CHEM350 FINAL

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A cation is a ___________ atom, and an anion is a ____________ atom.

positive negative

What is the fundamental difference between metals and nonmetals?

metals lose valence electrons, and nonmetals gain valence electrons

What is ionization energy?

the amount of energy needed in order for an electron to be taken away from an atom

Titration

the process of slowly reacting a base of unknown concentration with an acid of known concentration (or vice versa) until just enough acid has been added to react with all of the base

Molecules will conform to whatever shape keeps the ___________ _____________ of the __________ atom farthest apart.

valence electrons central

Convert 0.036 km into cm.

".036" km is 3600 cm. "Kilo" means "1,000". ".036" km times 1,000 is 36 m. "Centi" means ".01". 36 m divided by ".01" is 3600 cm.

molarity acid base volume

(___________ _acid)volume_ ______ = molarity_ _______(___________ _base)

Beta Decay Equation:

(_atomic #) (^atomic mass) ELEMENT -> (_atomic # + 1) (^atomic mass) ELEMENT

Alpha Decay Equation:

(_atomic #) (^atomic mass) ELEMENT -> (_atomic # - 2) (^atomic mass - 4) ELEMENT

Mg(OH)2 is the active ingredient in many laxatives. It can be made with the following reaction: Mg (s) + 2H2O (l) → Mg(OH)2 (s) + H2 (g) If a laxative manufacturer has 4.6 x 10^5 grams of Mg, how many grams of water must be used to have all of the Mg react to form Mg(OH)2?

(grams given/1) x (1 mole/grams per mole) = ((4.6 x 10^5 grams)/1) x (1 mole/ 24.3g) = 18,930.04 moles Mole ratio of Mg to water = 1:2 18,930.04(2) = 37,860.08 moles of water H2O: 2(1.01) + 16 = 18.02 grams/mole (1 mole/ 18.02g), so 37,860.08(18.02) = 682,238.68 grams About 682,338.68 grams of water must be used.

-122°C to °F

-188 degrees F

-40°F to °C

-40 degrees C

His bathwater temperature was to be exactly 38.0°C. You are his butler, and one morning while checking his bath temperature, you notice that it's 47.0°C. You plan to cool the 100.0 kg of water to the desired temperature by adding an aluminum-duckie originally at freezer temperature (-26.0°C). Of what mass (in kg) should the Al-duckie be? Assume that no heat is lost to the air. [Specific heat of Al = .90 J/(g°C); density of water = 1.00 g/ml].

-q_object=q_water + q_calorimeter q=m∙c(J/(g ∙ degrees C))∙∆T ∆T=T_Final-T_Initial=38.0℃-47.0℃=-9.0℃ 100.0 kg ∙1000=100000.0 g q_water=m∙c(J/(g ∙ degrees C))∙∆T q_water=100000.0 g ∙ 4.184(J/(g ∙ degrees C))∙-9.0℃ q_water=-3765600.0 J We will ignore the calorimeter specific heat, because we are not given any information about it. Thus, q_calorimeter=0. -q_object=-3765600.0+0 q_object=3765600.0 J q_object=m∙c(J/(g ∙ degrees C))∙∆T 3765600.0 J=m∙ .90(J/(g ∙ degrees C))∙(38.0℃--26.0℃) 3765600.0 J=m∙57.6 3765600.0 J/57.6=m m=65375.0 g OR (65375 g)/1000=65.4 kg The AL-duckie should be 65.4 kg in mass.

Convert the following number back into decimal: 1.080 x 10^-7

.0000001080

Convert the following number back into decimal: 9.450 x 10^-3

.009450

Convert 0.540 Pg into Tg.

.54 Pg is 540 Tg. "Peta" means 10^15. "Tera" means 10^12. (10^15)-(10^12)= 10^3. ".54" Pg times 10^3 is 540 Tg.

How many electrons are in the valence shell of the atoms: sodium

The average person uses 2,500.0 Cal of energy per day. How many Joules is that?

1 Cal. = 1,000 cal. 2500.0 Cal. ∙1000=2500000.0 cal. 1 cal. = 4.184 J 2500000.0 cal. ∙4.184=10460000.0 J OR 1.046 x 10^7 J 2500.0 Cal. is 1.046 x 10^7 J.

Lead has a density of 11.4 grams per mL, whereas gold has a density of 19.3 grams per cc. If I were to make two identical statues, one out of gold and the other out of lead, which would be heavier?

1 cc is the same as 1 mL. Thus, lead has a density of 11.4 g/mL, and gold has a density of 19.3 g/mL. Since gold is denser, the golden statue would be heavier than the lead statue.

Draw the Lewis structures for the following atoms: Ba.

1 pair of valence electrons

List the 8 chemical formulas of the homonuclear diatomic elements.

1) H_2 2) O_2 3) N_2 4) F_2 5) Cl_2 6) Br_2 7) I_2 8) At_2

What are the noble gases (5), and why are they important in chemistry?

1) He 2) Ne 3) Ar 4) Kr 5) Xe Because they have the ideal electron configurations--meaning their s and p orbitals have their highest energy levels full.

What three gases are involved in earth's three-tiered protection system against high-energy light that comes from the sun?

1) Oxygen 2) Nitrogen 3) Ozone

Name three periodic properties of atoms.

1) The ionization energy of atoms decreases from right to left and from top to bottom on the periodic table, in general. 2) The electronegativity of atoms decreases from right to left and from top to bottom on the periodic table, in general. 3) The atomic radii of atoms increase from right to left and from top to bottom on the periodic table, in general.

Based on their Lewis structures, which molecule is easiest to break apart: C2H4, PN, or H2.

1.) Electron configuration of H: 1s^1; H has 1 valence electrons, and it only needs 2, not 8 like the others. 2.) Electron configuration of P: 1s^2 2s^2 3s^2 3p^3; P has 5 valence electrons. 2.) Electron configuration of N: 1s^2 2s^2 2p^3; N 5 has valence electrons. 3.) Electron configuration of H: 1s^1; H has 1 valence electrons, and it only needs 2, not 8 like the others. 3.) Electron configuration of C: 1s^2 2s^2 2p^2; C has 4 valence electrons. Therefore, based on their Lewis structures, H_2 is the easiest molecule to break apart, because it is the only molecule of the above listed without double or triple covalent bonds--it only has a single bond. Thus, it would be the easiest to break apart.

List the 4 base metric units used to measure.

1.) Length: Meter 2.) Mass: Gram 3.) Time: Second 4.) Volume: Liter

Convert the following decimal number into scientific notation: 123.46

1.2346 x 10^2

In this reaction: 3CCl4 (g) + 2SbF3 (s) → 3CCl2F2 (g) + 2SbCl3 (s) Freon Suppose the chemist wanted to make 100.0 liters of Freon using excess antimony trifluoride. How many liters of carbon tetrachloride would the chemist need?

100.0 liters

bond angle of a bent molecule

105 degrees (or 92 degrees)

bond angle of pyramidal

107 degrees

bond angle of tetrahedral

109 degrees

Some parts of the western United States regularly reach temperatures of 115 degrees F in the summer. What is that in degrees C?

115 degrees F is equivalent to about 46 degrees C. The formula for this conversion is as follows: (degrees F -32)/1.80 = degrees C.

How many total atoms are in one molecule of C_12H_26O_10S?

12 + 26 + 10 + 1 = 49 atoms

A compound is decomposed into its constituent elements of carbon, nitrogen, and hydrogen. If, in the decomposition, 12.0 grams of carbon, 14.0 grams of nitrogen, and 2.0 grams of hydrogen were formed, what was the mass of the compound before it was decomposed?

12.0g + 14.0g + 2.0g = 28.0g 28.0g mass

Convert 15.0 degrees C into Fahrenheit

150.0 degrees C is equivalent to 59.0 degrees F. The formula for this conversion is as follows: (degrees F -32)/1.80 = degrees C.

bond angle of a linear molecule

180 degrees

Give the full electron configurations of the following atoms: S

1s^2 2s^2 2p^6 3s^2 3p^4

Give the full electron configurations of the following atoms: Rb

1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^1

Give the full electron configurations of the following atoms: Ti

1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^2

How many electrons are in the valence shell of the atoms: barium

How many significant figures: 12

N_2 + 3H_2 --> 2NH_3 How many grams of NH_3 can be prepared from 1.5 moles of N_2?

2 moles of NH_3 prepares 1 mole of N_2 2(1.5) = 3 moles of NH_3 can be prepared N: 14.0g H_3: 3(1.01) = 3.03g 3.03g + 14.0g = 17.03g in 1 mole 3(17.03g) = 51.09g About 51.1g

Draw the Lewis structures for the following atoms: Ge.

2 pairs of valence electrons

Draw a Lewis structure for FNO

2 pairs of valence electrons on O plus double bond on N with 1 pair of electrons and a covalent bond to F with three pairs on valence electrons

-33°C to K

240 K

N_2 + 3H_2 --> 2NH_3 How many moles of hydrogen gas are needed to prepare 18 moles of NH_3?

What is the vapor pressure in torr for water at 28 degrees Celsius?

28.3

74°F to K

296 K

Write a balanced chemical equation for the complete combustion of butyraldehyde (C_4H_8O).

2C_4H_8O + 11O_2 --> 8CO_2 + 8H_2O

A chemist wants to perform the following reaction: CaCO3 (s) + 2HCl (g) → CaCl2 (aq) + CO2 (g) + H2O (l) Which substances can she use Gay-Lussac's Law to relate to one another?

2HCl (g) and CO2 (g)

Write a balanced chemical equation for the decomposition of RbNO_3.

2RbNO_3 --> 2Rb + N_2 + 3O_2

How many significant figures: 3.40 x 10^3

How many valence electrons are in the following electron configuration? 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^1

Draw the Lewis structures for the following atoms: Te.

3 pairs of valence electrons

Convert 3.5 Mg into Gg.

3.5 Mg is 3.5 x 10^(-12) Gg. "Milli" means 10^(-3). "Giga" means 10^9. 10^(-3) - 10^9= 10^(-12). Thus, 3.5 x 10^(-12).

Convert 31.9 ng into fg.

31.9 ng is 3.19 x 10^7 fg. "Nano" means 10^(-9). "Femto" means 10^(-15). 10^(-9) - 10^(-15)= 10^6. 31.9 ng times 10^6 3.19 x 10^7 fg.

Convert the following number back into decimal: 3.52 x 10^7

35200000

What is wrong with the following electron configuration: 1s22s22p63s23p63d104s24p5

3d^10 and 4s^2 have switched positions.

What is wrong with the following electron configuration: 1s22s22p63s23p74s23d10

3p^7 doesn't exist in the periodic table--only 3p^6--, so this is what is wrong.

Draw a Lewis structure for CH4

4 H's bonded to a single carbon

Convert the following decimal number into scientific notation: 0.0004030

4.030 x 10^-4

How many Joules are in a calorie?

4.184 Joules

Convert the following decimal number into scientific notation: 0.4321

4.321 x 10^-1

142.1 g of an unknown substance absorbs 40.0 kJ of heat and increases its temperature by 32.3 degrees C. What is its specific heat?

40.0 kJ∙1000=40000.0 J q=m∙c(J/(g ∙ degrees C))∙∆T ∆T=T_Final-T_Initial 40000.0 J=142.1 g∙c(J/(g ∙ degrees C))∙(32.3 degrees C) 40000.0 J=4589.8∙c(J/(g ∙ degrees C)) c=8.7(J/(g ∙ degrees C)) The unknown substance's specific heat is about 8.7 in (J/(g ∙ degrees C)).

Convert 43.5 km into m.

43.5 km is 43500 m. "Kilo" means 1,000. "43.5" km times 1,000 is 43500 m.

How many significant figures: 10.020

A nurse injects 5.20 cc of medicine into a patient. How many liters is that?

5.2 cc of medicine is .0052 liters. Cubic centimeters equal "cc's". Cubic centimeters are the same as mL. So, 5.2 mL is how many liters? "Milli" means ".001". 5.2 mL times .001 is .0052 L.

How many electrons are in the valence shell of the atoms: oxygen

How many significant figures: 0.0120350

Convert the following decimal number into scientific notation: 6,200,000

6.2 x 10^6

How old is a fossil that has 6.25 grams of carbon-14 remaining where 43.75 grams decayed to carbon-12 using 5,700 years as the half-life?

6.25 g + 43.75 g = 50 g originally 1/2 decays every 5,700 years, so... 50 g/ 2 = 25 g after 5,700 years 25 g/ 2 = 12.5 g after [2(5,700)] 11,400 years 12.5 g/ 2 = 6.25 g after [3(5,700)] 17,100 years The fossil would be about 17,100 years old.

Solution A has a mass of 60 g. Solution B has a mass of 40 g. When they are mixed, a chemical reaction occurs in which gas is produced. If the mass of the final mixture is 85 g, what mass of gas was produced?

60g + 40g = 100g 100g - 85g = 15g 15g of gas

Convert the following number back into decimal: 6.34 x 10^3

6340

A solid has a mass of 35 g. When it is mixed with a solution, a chemical reaction occurs. If the final total mass of all the products is 85 g, what was the mass of the original solution?

85g -35g = 50g 50g mass

A chemist decomposes 150.0 grams of water (H_2O). If the chemist finds that he makes 16.7 grams of hydrogen from the decomposition, how much oxygen must he have produced?

8g of O/1g of H to form water (H_2O) 16.7g x 8 = 133.6g 133.6g of oxygen

N_2 + 3H_2 --> 2NH_3 How many moles of nitrogen gas are needed to react with 27 moles of H_2?

37°C to °F

99 degrees F

base

A _______ is defined as a molecule that accepts protons or H+ ions.

STP = 1.000 atm K = oC + 273.15 K = 25 oC + 273.15 25 oC = 298.15K 760torr/1atm=780torr/atm 760atm = 780 Atm = 1.03 7.8 ∙10^2 torr=1.03 atm (P_1 V_1)/T_1 =(P_2 V_2)/T_2 (1.03(64.1))/(298.15)=(1∙V_2)/273 ((65.787)/(298.15)=V_2/273)273 V_2=(17959.851)/(298.15)=60.2mL The volume of the methane at STP would be 60.2 mL.

A bacterial culture isolated from sewage produced 64.1 mL of methane gas at 25oC and 7.80 x 102 torr. What would the volume of the methane be at STP?

Constant temperature = Boyle's Law P_1 V_1=P_2 V_2 775(1.5) = 675(V_2) V_2 = 1.72L Its new volume will be 1.72L at this higher altitude.

A balloon is filled with hydrogen at a temperature of 20oC and a pressure of 775 mmHg. If the balloon's original volume was 1.50 liters, what will its new volume be at a higher altitude, where the pressure is only 675 mmHg? Assume the temperature stays the same.

A box is measured to be 1.3 m by 2.4 m by 3.6 m. What is its volume in cubic centimeters?

A box is measured to be 1.3 m by 2.4 m by 3.6 m. "Centi" means 100. 1.3 m times 100 is 130 cm. 2.4 m times 100 is 240 cm. 3.6 m times 100 is 360 cm. 130 cm times 240 cm times 360 cm is 11232000 cm^3. The volume in cubic centimeters is 11232000 cm^3.

Have: 14M HBr Need: 500mL 5.3M HBr Let us have H_2 O as our amphiprotic substance. (molarity_acid)volume_acid=molarity_base(volume_base) (14v_a = 5.3(500))/14 v_a = 189.2857mL ≈189.3 mL 500 - 189.2857 = 310.7143mL ≈ 310.7 mL In order for a chemist to make 500mL of 5.3M HBr from 14M HBr, the chemist would have to take 189.3mL of 14M HBr and dilute it with 310.7mL of water. The result would be 500mL of 5.3M HBr.

A chemist has 14.0 M HBr and would like to use it to make 500.0 mL of 5.3 M HBr. Describe how she should do this.

Molecular mass of NaOH = 23 + 16 + 1.01 = 40.01 1 mole = 40.01g (40.01)/1=950/moles 40.01(moles) = 950 40.01 Moles ≈23.7441 100mL = .1L Molarity = (#moles)/(#Liters) = (23.7441)/2≈11.8720M Have: 2000mL of 11.872M NaOH Need: 100mL of .1M NaOH We can use water to dilute the solution. molarity_acid volume_acid=molarity_base volume_base 11.872v_a = .1(100) (11.872 v_a = 10)/11.872 .8423 = v_a 100 - .8423 = 99.1577mL The chemist should dilute .8423mL of the stock solution with 99.1577mL of water.

A chemist makes a "stock" solution of NaOH by dissolving 950.0 grams in enough water to make 2.00 liters of solution. If, later on, he wants to use this stock solution to make 100.0 mL of 0.10 M NaOH, what would he need to do?

Sulfuric Acid = H_2 SO_4 Calcium Hydroxide = Ca(OH)_2 Acid + Base --> Salt + Water H_2 SO_4 + Ca(OH)_2 --> CaSO_4 + 2H_2 O

A chemist mixes sulfuric acid (H2S04) with calcium hydroxide. Give the balanced chemical equation that represents the resulting reaction.

34.3mL of 3.5M HCl + 50mL of ?M NaOH M_1 V_1=M_2 V_2 3.5 * 34.3 = M_2(50) (120.05 = M_2 (50))/50 M_2 = 2.401 The concentration of the NaOH solution is 2.401M.

A chemist needs to know the concentration of some NaOH that is in the laboratory. To find this out, she titrates a 50.0 mL sample of the solution with 3.5 M HCl. If it takes 34.3 mL of the HCl to reach the titration endpoint, what is the concentration of the NaOH solution?

Potassium Hydroxide: KOH H_2 CO_3+2KOH→K_2 CO_3+2H_2 O Coefficients represent mole ratios. 1 mole of K_2 CO_3 = 2(39.1) + 12 + 3(16) = 138.2g (.23 mol)(138.2g) = 31.786 g About 31.8g of potassium carbonate are produced.

A chemist reacts 50.0 mL of 4.5 M carbonic acid (H2CO3) with excess potassium hydroxide. How many grams of potassium carbonate are produced?

The chemist can use the one with 5.0 M concentration to make the desired acid, because the chemist can dilute the concentration to 4.3 M.

A chemist wants to make a solution of 4.3 M HCl. There are two solutions of HCl that he can find on the shelf. One has a concentration of 5.0 M, while the other has a concentration of 3.0 M. Which solution can the chemist use to make the desired acid? Explain.

Classify the following reaction as decomposition, formation, complete combustion, or none: C_6H_12O_6 (s) + 6O_2 (g) → 6CO_2 (g) + 6H_2O (g).

A complete combustion reaction is when oxygen is added to a compound containing carbon and hydrogen and carbon dioxide and water are produced; this is what is accomplished in this reaction. Therefore, this is a reaction is neither a complete combustion reaction.

What is the difference between complete combustion and incomplete combustion?

A complete combustion reaction is when oxygen is added to a compound containing carbon and hydrogen, where carbon dioxide and water are produced. However, an incomplete combustion reaction is when oxygen is added to a compound containing carbon and hydrogen, where EITHER carbon monoxide or carbon is produced in addition to water.

Anhydride

A compound derived from another compound by the removal of water that will combine with water to form an acid or base.

Classify the following reaction as decomposition, formation, complete combustion, or none: 2NaHPO_4 (s) → 2Na (s) + H2 (g) + 2P (s) + 4O_2 (g).

A decomposition reaction breaks down a compound into its elements, and this what was accomplished in this reaction. Therefore, this reaction is a decomposition reaction.

Classify the following reaction as decomposition, formation, complete combustion, or none: 2HBr (l) + Ca(OH)_2 (s) → 2H_2O (l) + CaBr_2 (aq).

A decomposition reaction breaks down a compound into its elements, so this is not a decomposition reaction. A formation reaction starts with two or more elements and produces one compound, so this is not a formation reaction. A complete combustion reaction is when oxygen is added to a compound containing carbon and hydrogen and carbon dioxide and water are produced, so this is not a combustion reaction. Therefore, this reaction is neither a decomposition, formation, nor a complete combustion reaction.

Classify the following reaction as decomposition, formation, complete combustion, or none: NaCl (s) + AgNO_3 (aq) → AgCl (s) + NaNO_3 (aq).

Classify the following reaction as decomposition, formation, complete combustion, or none: 2H_2 (g) + O_2 (g) → 2H_2O (l)

A formation reaction starts with 2 or more elements and produces one compound, and this is what was done here by reacting hydrogen with oxygen to produce water. Therefore, this reaction is a formation reaction.

Which has more liquid: a glass holding 0.600 kL or a glass holding 120 mL? Why?

A glass holding .600 kL holds more liquid than a glass holding 120 mL. "Kilo" means "1,000", so one kiloliter is 1,000 liters. Thus, .6 kiloliters are 600 liters. "Milli" means one-thousandth. Thus, 600 liters times 1,000 is 600,00 mL. 600,000 mL equals .6 kL, and 600,000 mL is more liquid than 120 mL.

Which of the following contains no matter? -A rock -A balloon full of air -A balloon full of helium -A lightning bolt

A lightning Bolt

The liquids vapor pressure decreases during that time.

A liquid's temperature is lowered from 60oC to 10oC. Did the the liquid's vapor pressure increase, decrease, or stay the same during that time?

Explain the difference between polar covalent bonds and purely covalent bonds.

A polar covalent bond is a type of bind where the electrons of the central atom are not being pulled in exactly opposite directions, creating a net pull on the central atom's electrons, and the electrons are shared unequally as a result. On the other hand, purely covalent bonds are a type of bond where the electrons are being pulled in exactly opposite directions by the same atom type--such as C and C, not C and H. Therefore, the main differences between polar covalent bonds and purely covalent bonds are found in the structure of the molecule--what type(s) of atoms surround the central atom and how they pull on the central atom. Polar covalent bonds also unequally share their electrons, but purely covalent bonds equally share their electrons.

500mL of ?M H_2 SO_4 + 345.1mL of 1.2M KOH 345.1 mL = .3451 L 500 mL = .5 L M_1 V_1=M_2 V_2 M_1= 1.2(.3451) = .414 1:2 = H_2 SO_4 : KOH (.414)/2 = .207 mol (.207 mol) / (.5 L) = .414M M_1 = .4 The concentration of the H_2 SO_4 is .4M.

A solution of H2SO4 is titrated against 1.2 M KOH. A total of 345.1 mL of KOH must be added to a 500.0 mL sample of H2SO4 in order to reach the endpoint. What is the concentration of the H2SO4?

Total Pressure = 5 + 2 + .5 = 7.5 atm P_P=XP_T N: 5 = 7.5X => .67 O: 2 = 7.5X => .27 Ar: .5 = 7.5X => .07 The total pressure is 7.5 atm. The mole fraction of nitrogen is .67. The mole fraction of oxygen is .27. The mole fraction of .07.

A steel container is filled with 5.00 atms of nitrogen, 2.00 atms of oxygen, and 0.50 atms of argon. What is the total pressure in the vessel and the mole fraction of each gas?

P_1=125.0 atm;T_1=20.0oC;Volume=constant P_2= ?;T_2=65oC;Volume=constant K = oC + 273.15 20 oC = 293.15K 65 oC = 338.15K (P_1 V_1)/T_1 =(P_2 V_2)/T_2 =>P_1/T_1 =P_2/T_2 (125/(293.15)=P_2/(338.15))338.15 P_2=(42268.75)/(293.15)=144.2 atm The new pressure is 144.2 atm.

A steel container with a volume that cannot change is filled with 125.0 atms of compressed air at 20.0 oC. It sits out in the sun all day, and its temperature rises to 65.0 oC. What is the new pressure?

Why are the bond angles in a pyramidal shape smaller than the bond angles in a tetrahedral shape?

A tetrahedral shape has four groups of valence electrons with no non-bonding electrons, so it has four bonds. A pyramidal has four groups of valence electrons with one pair of non-bonding electrons, so it has three bonds and one pair of non-bonded electrons. The pair of non-bonded electrons push on the bonds with more force than the bonds push on themselves. Thus, the pyramidal has a smaller bond angle than the tetrahedral.

Salt Water

Acid + Base --> _____ + ________

Acid

Acid or Base? Blue litmus paper red

Base

Acid or Base? Feels slippery

Base

Acid or Base? Tastes bitter

Name these ionic compounds: Ag_3N.

Ag = Ag^+ as an ionic compound; Ag is a cation, so its name is Silver. N = N^(3-) as an ionic compound; Br is an anion, so add "ide" as a suffix to its name. Silver nitride

Give the chemical formulas for the following molecules: aluminum sulfide.

Aluminum = Al^(3+) Sulfide = S^(2-) Different numerical values, so drop the signs, switch the numbers, and make the superscripts subscripts. Al_2 S_3

acid base water

Always add the ______ or _______ to the ________, not the reverse.

acid

An ______ is a molecule that donates H^+ ions.

Polyprotic acid

An acid that can give away more than one H^+ ion (or proton)

In a 3D Lewis structure, a solid line signifies what?

An angle even with the plane of the paper.

In a 3D Lewis structure, a dotted line signifies what?

An angle that extends behind the plane of the paper.

In a 3D Lewis structure, a triangular bond signifies what?

An angle that extends forward from the plane of the paper.

What is the difference between an atom and a molecule?

An atom is the smallest unit of matter, whereas, a molecule is multiple atoms bonded together.

Anwer the picture question.

Answer is...J

?L of 1.5M AgNO3 + excess NaBr 100g AgBr AgBr = 107.9 + 79.9 = 187.8g/mole 100/187.8 = .53 moles of AgBr need to be produced AgNO3 : AgBr => 1:1, so .53moles of AgNO3 Molarity = (#moles)/(#liters)=>1.5=(.53)/L => .53/1.5 = L = .353 About .35L of silver nitrate must be added to an excess sodium bromide.

Aqueous sodium bromide and silver nitrate will react to form solid silver bromide (a compound used in photography) and sodium nitrate: NaBr (aq) + AgNO3 (aq) --> AgBr (s) + NaNO3 (aq) If a chemist needs to produce 100.0 grams of silver bromide, how many liters of 1.5 M silver nitrate must be added to an excess of sodium bromide?

SO_2 = 32.1 + 2(16) = 64.1g/mol (64.1)/1=15/mol 64.1mol = 15 Mol = .23 NO = 14 + 16 = 30g/mol mol=(11.2)/30= .37 SO_3=32.1+3(16)=80.1g/mol mol=(2.5)/(80.1)= .03 Total moles = .23 + .37 + .03 = .64 moles total X = (#moles in compound)/(total #moles in mixture) SO_2 = (.23)/(.64)=.3594 NO = (.37)/(.64)= .5781 SO_3 = (.03)/(.64)= .0469 The mole fraction of SO_2 is .36; the mole fraction of NO is .58; and the mole fraction of SO_3 is .05.

As part of an environmental experiment, the mixture of gases released from a smokestack is collected in a balloon. If the mixture is analyzed and found to contain 15.0 g of S02 gas, 11.2 g of N0 gas, and 2.5 g of S03 gas, what is the mole fraction of each component in the mixture?

Two different compounds are formed by the elements carbon and oxygen. The first compound contains 42.9% by mass carbon and 57.1% by mass oxygen. The second compound contains 27.3% by mass carbon and 72.7% by mass oxygen. Show that the data are consistent with the Law of Multiple Proportions.

Assume a 100.0g sample of such compounds is used. Sample 1: 42.9g carbon and 57.1g oxygen 57.1g O/ 42.9g C = 1.33g O/C Sample 2: 27.3g carbon and 72.7g oxygen 72.7g O/ 27.3g C = 2.66g O/C (2.66g O/C)/(1.33g O/C) = 2 <-- A whole number ratio, just like the Law of Multiple Proportions tells us.

List the four assumptions of Dalton's atomic theory.

Assumption 1: All elements are composed of indivisible atoms. *Later on, however, atoms were shown to be divisible. Assumption 2: All the atoms in a given element have the same properties. *This was later proven to be false due to isotopes. Assumption 3: Atoms of different elements have different properties. Assumption 4: Compounds are formed by atoms combining. Atoms can only join together in whole-number ratios.

What is the mass of an iodine atom (I) in grams?

Atomic Mass: 1.00 amu = 1.66 x 10^-24 g Atomic Mass = 126.9 amu, so 126.9(1.66 x 10^-24) = 2.1 x 10^-22 g

What is the mass of a Na_2CrO_4 molecule in kg?

Atomic Mass: 1.00 amu = 1.66 x 10^-24 g Na_2 = 2(23.0) = 46.0 amu Cr = 52.0 amu O_4 = 4(16.0) = 64.0 amu 46.0 + 52.0 + 64.0 = 162.0 amu 162.0(1.66 x 10^-24) = 2.7 x 10^-22 g 1 kg = 1000 g (2.7 x 10^-22 g)/1000 = 2.7 x 10^-25 kg The mass is 2.7 x 10^-25 kg.

How many moles of Cr atoms are in a 300.0-gram sample of Cr?

Atomic mass = mass in g of 1 mole of an element Cr: 52.0 amu = 52.0 g is 1 mole of Cr (300.0 g/52.0 g) = (x moles/1 mole) (300.0g = 52.0g(x))/52.0g x = about 5.7692 moles

How many moles of NaHCO_3 are in a 175-gram sample of the compound?

Atomic mass = mass in g of 1 mole of an element Na: 23.0 g H: 1.01g C: 12.0g O_3: 3(16.0)g = 48.0g 23.0g + 1.01g + 12.0g + 48.0g = 84.01g Thus, 1 mole of NaHCO_3 is 84.01g. (175g/x moles) = (84.01g/ 1 mole) (175g = 84.01g(x))/84.01 x = about 2.0831 moles

How many grams are in 25.0 moles of Ce?

Atomic mass = mass in grams of 1 mole Ce: 140.1 amu or g in 1 mole 140.1(25) = 3502.5g in 25 moles

What is Avogadro's Number and what does it represent?

Avogadro's number is 6.02 x 10^23. It represents one mole, so Avogadro's number of an element will yield one mole of that element.

Which of the following are empirical formulas? a. C12H24O10 b. K2S2O3 c. CaN2O6

B and C

Why should a calorimeter always be made from an insulating material?

Because if it is not, then heat may escape the calorimeter. This would lead to inaccurate results from the calorimeter.

Why do chemists use two different naming systems for compounds?

Because it helps them to determine if a compound is ionic or covalent just by the name. This is why chemists have one naming system for ionic compounds and one for covalent compounds.

Some diet books tell you that an excellent way to lose weight is to drink ice-cold water. Why?

Because it helps you burn excess calories. Your body has an internal "thermometer", and when you intake something colder than your internal temperature, your body has to heat that substance up to your body's temperature. This takes energy to do, so you end up burning some calories in the process.

Why must a chemical reaction be balanced before it can be used in stoichiometry?

Because only balanced chemical reactions occur in nature. In order for a chemical reaction or equation to be balanced, there must be an equal number of atoms on both sides of the equation. In real life, when a chemical reaction takes place, there is always an equal number of product and reactant atoms, because atoms cannot be destroyed or created.

Why does ice float on top of water?

Because the ice is less dense

Use table 13.3 to find the ∆Hfo ∆Hfo = 49 2C6H6 (l) + 〖15O〗_2 (g) 12CO_(2 ) (g)+〖6H〗_2 O (g) ∆Ho = ∑∆Hfo (products)-∑∆Hfo (reactants) ∆Ho = (12[-394] + 6[-242])-(2[49] + 0) ∆Ho = -6278 The ∆Ho for this reaction is -6278 kJ.

Benzene (C6H6) is a toxic liquid with a ∆Hfo of 49.00 kJ/mole. The best method for disposing of benzene is to burn it in the presence of excess oxygen. What is the ∆Ho for this reaction? (You should know all of the phases in this problem, so use Hess's Law).

How can you determine from the periodic chart whether a compound is ionic or covalent?

By examining whether the atoms that compose the compound are metal or nonmetal: If the compound contains at least one metal atom and at least one nonmetal atom, it is an ionic compound; but, if the compound is made of only nonmetal atoms, it is a covalent compound.

How can you experimentally determine whether a compound is ionic or covalent?

By testing a compounds conductivity in water: If the compound is dissolved in water, and the water conducts electricity, it is ionic; if the compound is dissolved in water, and the water does not conduct electricity, it is a covalent compound.

An unknown compound was decomposed into 63.2 g carbon, 5.26 g hydrogen, and 41.6 g oxygen. What is its empirical formula?

C = 12.0, so 63.2/12.0 = 5.2 moles H = 1.01, so 5.26/1.01 = 5.2 moles O = 16.0, so 41.5/16.0 = 2.6 moles Thus, the mole ratios of C to H to O is 2:2:1. The empirical formula is C2H2O.

A dry-cleaning compound was decomposed into 14.5 g carbon and 85.5 g chlorine. In a separate experiment, its molar mass was determined to be 166.0 grams. What is the molecular formula of the compound?

C = 14.5g; 12.0g Cl = 85.5g; 35.5g So, one mole is 166.0g. 14.5/12.0 = 1.2 85.5/35.5 = 2.4 Mole ratio of C to Cl = 1:2 Thus, the empirical formula is CCl2. C +Cl2 = 12.0 + 2(35.5) = 83.0 166.0/83.0 = 2.0 Thus, the molecular formula is C2Cl4.

Balance the following equation: CO_2 (g) + H_2O (l) → C_6H_12O_6 (s) + O_2 (g).

C=/C_6 <--Should be 6C, not C O_2 + O =/O_6 + O_2 <--Should be 6O, not O H_2=/H_12 <--Should be 6H_2, not H_2 Balanced equation: 6CO_2 (g) + 6H_2O (l) → C_6H_12O_6 (s) + 6O_2 (g).

A compound with the empirical formula CH has a molar mass of 78 grams/mole. What is its molecular formula?

CH = 12.0 + 1.01 = 13.01 78.0/13.01 = About 6 The molecular formula is C6H6.

List the chemical formula (including charge) for following ion: acetate.

C_2 H_3 O_2^-

What is the chemical formula of a molecule that is made up of 3 carbon atoms, 5 hydrogen atoms, 3 chlorine atoms, and one oxygen atom?

C_3H_5Cl_3O

Balance the following equation: C_8H_18 (l) + O_2 (g) → CO_2 (g) + H_2O (g).

C_8=/C <--Should be 8C, not C H_18=/H_2 <--Should be 9H_2, not H_2 O_2=/O_2 + O <--Should be 2O_2 and O_2 + 2O Balanced equation: 2C_8H_18 (l) + 25O_2 (g) → 16CO_2 (g) + 18H_2O (g).

Write a balanced chemical equation for the formation of Ca(HSO_4)_2.

Ca + H_2 + 2S + 4O_2 --> Ca(HSO_4)_2

Remember that a food calorie (_____) is _______ chemistry calories (____).

Cal 1,000 cal

Give the balanced chemical equation for the reaction in which aqueous calcium nitrate reacts with aqueous sodium carbonate to produce solid calcium carbonate (chalk) and aqueous sodium nitrate.

Calcium Nitrate: Ca^(2+)+NO_3^-= Ca(NO_3 )_2 Sodium Carbonate: Na^++CO_3^(2-)= Na_2 CO_3 Calcium Carbonate: Ca^(2+)+CO_3^(2-) =Ca_2 (CO_3 )_2 Sodium Nitrate: Na^++ NO_3^-= NaNO_3 2Ca(NO_3 )_2 (aq) + 2Na_2 CO_3 (aq) → Ca_2 (CO_3 )_2 (s) + 4NaNO_3 (aq)

Give the chemical formula for calcium nitrate.

Calcium: Ca^(2+) Nitrate: NO_3^- Drop the signs and switch the numbers: Ca(NO_3 )_2

It splits into 1 ion. 7.5/128.08 = .06moles 2 + 2 = 4ions .03 + .06 = .09moles 200g = .2kg Molality = (#moles of solute)/(#kg of solvent)=(.09)/(.2)=.45 ΔT = -i(K_f)m ΔT = -1(5.12).45 ΔT = -2.304 5.5 - 2.304 = 3.196 The freezing point of this solution would be about 3.2ºC.

Calculate the freezing point of a solution of 5.00 g of diphenyl, C12H10, and 7.50 g of naphthalene, C10H8 dissolved in 200.0 g of benzene (Kf = 5.12°C/m, fp = 5.50°C).

ΔH of H_2=0 To get what we need, we will need to reverse reactions 1 and 2, changing the sign of their ΔH, and we need to half reaction 1 and 3. This will give us the following reactions: 1) NH_3 (g) → 〖1/2 N〗_2 (g)+ 1 H_2 (g) + .5 H_2 (g) ΔH = 45.9 kJ 2) CH_4 (g) --> C (s) + 2 H_2 (g) ΔH = 74.9 kJ 3) 〖1/2 H〗_2 (g) + C (s) + 〖1/2 N〗_2 (g) --> HCN (g) ΔH = 135.15 kJ 1 H_2 (g) + 2 H_2 (g) = 3 H2 (g) So we have: CH4 (g) + NH3 (g) --> HCN (g) + 1 H2 (g) + 2 H2 (g) => CH4 (g) + NH3 (g) --> HCN (g) + 1 H2 (g) + 2 H2 (g) ΔH = 45.9 kJ + 74.9 kJ + 135.15 kJ = 255.95 kJ The ΔH of the above reaction is 255.95 kJ.

Calculate ΔH for the reaction CH4 (g) + NH3 (g) --> HCN (g) + 3 H2 (g), given: 1) N2 (g) + 3 H2 (g) --> 2 NH3 (g) ΔH = -91.8 kJ 2) C (s) + 2 H2 (g) --> CH4 (g) ΔH = -74.9 kJ 3) H2 (g) + 2 C (s) + N2 (g) --> 2 HCN (g) ΔH = +270.3 kJ

C2H6 (g) + 3½ O2 (g) --> 2 CO2 (g) + 3 H2O (l) becomes... 2 CO2 (g) + 3 H2O (l) --> C2H6 (g) + 3½ O2 (g) And ΔH (-1560.0 kJ) becomes...1560kJ 3 O2 (g) + ½ O2 (g) = 3½ O2 (g) 2 H2O (l) + H2O (l) = 3 H2O (l) The only molecules left create this reaction: C2H4 (g) + H2 (g) --> C2H6 (g) => C2H4 (g) + H2 (g) --> C2H6 (g) -1411 kJ + 1560kJ + -285.8 kJ = -136.8 kJ ΔH for the above reaction is -136.8 kJ.

Calculate ΔH for the reaction: C2H4 (g) + H2 (g) --> C2H6 (g) from the following data. C2H4 (g) + 3 O2 (g) --> 2 CO2 (g) + 2 H2O (l) ΔH = -1411 kJ C2H6 (g) + 3½ O2 (g) --> 2 CO2 (g) + 3 H2O (l) ΔH = -1560.0 kJ H2 (g) + ½ O2 (g) --> H2O (l) ΔH = -285.8 kJ

Name the following ion: CO_3 ^2-.

Carbonate

Name these ionic compounds: CdO.

Cd = 〖Cd〗^(2+) as an ionic compound; Cd is a cation, so its name is Cadmium. O = O^(2-) as an ionic compound; O is an anion, so add "ide" as a suffix to its name. Cadmium oxide

Give the chemical formulas for the following molecules: cesium nitride.

Cesium = Cs^+ Nitride = N^(3-) Different numerical values, so drop the signs, switch the numbers, and make the superscripts subscripts. Cs_3 N

Classify the following as a physical or chemical change: charcoal is burned in a grill.

Chemical

Name the following ion: ClO_3 ^-.

Chlorate

Name the following ion: CrO_4 ^2-.

Chromate

Give the chemical formulas for the following molecules: chromium (III) oxide.

Chromium (III) = Cr^(3+) Oxide = O^(2-) Different numerical values, so drop the signs, switch the numbers, and make the superscripts subscripts. Cr_2 O_3

Citric Acid = C₆H₈O₇ Molar Mass of C₆H₈O₇= 6(12) + 8(1.01) + 7(16) = 192.08 g/mol The molar mass of citric acid is 192.08 grams per mole.

Citric acid, abbreviated H3Cit, gives Kool-Aid its tart taste. If 31.60 mL of 0.339 M NaOH neutralizes a 0.685 g sample of citric acid, what is the molar mass of citric acid? H3Cit + 3NaOH --> Na3Cit + 3H2O

NaOH is a base, so HCO_3^- must be an amphiprotic substance.

Consider the following reactions: HCO3- + NaOH → Na+ + CO32- + H2O and H2O + HCO3- → H2CO3 + OH- Which substance in the two equations is acting as an amphiprotic substance?

When ionic compounds dissolve in water, they divide into two or more ions, whereas, when polar covalent compounds dissolve in water, they dissolve one molecule at a time.

Contrast the way ionic compounds dissolve in water with the way that polar covalent compounds dissolve in water.

Name the ionic compound: CsI.

Cs = Cesium I = Iodine Cesium Iodide

Name these ionic compounds: CsF.

Cs = 〖Cs〗^+ as an ionic compound; Cs is a cation, so its name is Cesium. F = F^- as an ionic compound; F is an anion, so add "ide" as a suffix to its name. Cesium fluoride

What is the mass of a CuCl2 sample if it contains 0.122 moles of the compound?

Cu: 63.5g Cl: 2(35.5) = 71.0g 63.5g + 71.0g = 134.5g is 1 mole 134.5(.122) = 16.409 g The mass is 16.409 g.

Gold has a density of 19.3 grams per cc. If a gold nugget has a mass of 35.6 kg, what is its volume?

Density equals mass/volume. 35.6 kg times 1000 equals 35600 g. Thus, 19.3/1 equals 35600/volume. Multiply both sides by volume. This will give you 19.3(volume)=35600. Divide both sides by 19.3. Volume=1844.559585. Thus, the volume is 1844.6 cc. 1 cc equals 1 mL. Thus, the volume is 1844.6 mL (or 1.8446 mL x 10^3).

18 kJ

Determine the activation energy for the following reaction if we assume the product line is at 70 and the reaction line is at 18.

Potassium chloride = KCl = 39.1 + 35.5 = 74.6g/mole 250mL = .25L .010M = .01 moles/L g = (74.6)(.01)(.25) g = .1865 The number of grams of potassium chloride required to make 250mL of a .010M solution would be .1865g.

Determine the number of grams of potassium chloride required to make 250 mL of a 0.010 M solution.

Balanced equation: CO_2 + H_2 O --> H_2CO_3 Acid or base: Carbonic Acid is an acid.

Determine what acid or base is formed when the following anhydrides are placed in water. a) give balanced equation and b) state whether the product is an acid or base CO2

Balanced equation: CaO+ H_2 O --> Ca(OH)_2 Acid or base: Base

Determine what acid or base is formed when the following anhydrides are placed in water. a) give balanced equation and b) state whether the product is an acid or base CaO

In the decomposition of 2.1 moles of dinitrogen pentoxide, how many moles of oxygen would be formed?

Dinitrogen pentoxide: N_2O_5 Reaction: 2N_2O_5 -> 2N_2 + 5O_2 2 moles of N_2O_5 is to 2 moles of N_2 + 5 moles of O_2. 2x = 2.1 => x = 1.05 So, 5(1.05) = 5.25 moles There are about 5.25 moles of oxygen formed.

Y-axis = energy in kJ X-axis = reaction coordinate Start at (0,0) and draw a curve up to 100 kJ and then curve down to the x-axis.

Draw an energy diagram for a reaction that has a large activation energy and a ∆H of zero.

State Gay-Lussac's Law and explain how it is used.

Gay-Lussac's Law states that, "The stoichiometric coefficients in a chemical equation relate the volumes of gases in the equation as well as the number of moles of substances in the equation." It is used to find the volume of any and all gases in a chemical equation using the coefficients of each substance.

Molarity = (#moles)/(#Liters) = (3.15)/(2.1)=1.5M The concentration would be 1.5M.

Give the concentration in M: 3.15 moles of HNO3 are dissolved in enough water to make 2.1 liters of solution

Molecular mass of KOH = 39.1+16+1.01=56.11 1 mole = 56.11g (56.11)/1=(324.1)/moles (56.11(moles) = 324.1)/56.11 Moles ≈ 5.7762 435 mL = .435 L Molarity = (#moles)/(#Liters) = (5.7762)/(.435)≈13.2785≈13.3M The concentration would be 13.3M.

Give the concentration in M: 324.1 grams of KOH are dissolved in enough water to make 435 mL of solution

Ammonia = NH_3 Carbonic Acid = H_2 CO_3 2NH_3 + H_2 CO_3 --> 2NH_4+CO_3

Given that ammonia (NH3) is a base, determine the reaction that occurs between H2C03 and ammonia and give the balanced chemical equation.

What is the concept of ground state and why is it so important in chemistry?

Ground state is the state in which matter is in when it is at its lowest possible energy level. Ground state is so important in chemistry, because all forms of matter want to be in ground state. Thus, ground state greatly helps scientists to be able to make predictions and models of matter.

To make a phosphorus fertilizer, agricultural companies use the following reaction: Ca3P2O8 + 2H2SO4 + 4H2O → CaH4P2O8 + 2CaH4SO6 fertilizer If 1.50 x 10^4 grams of H2SO4 are reacted with excess Ca3P2O8 and H2O, how many grams of fertilizer can be made?

H2SO4: 1.50 X 10^4 grams; 2(1.01) + 32.1 + 4(16) = 98.12 g/mole (grams given/1) x (1 mole/grams per mole) = ((1.50 x 10^4 grams)/1) x (1 mole/98.12g) = about 152.87 moles "If 152.87 moles of H2SO4 are reacted with excess Ca3P2O8 and H2O, how many grams of fertilizer can be made?" Mole ratio of Ca3P2O8 to H2SO4 to H2O to fertilizer = 1:2:4:1 152.87/2 = 76.44 moles of fertilizer CaH4P2O8 (fertilizer): 40.1 + 4(1.01) + 2(31.0) + 8(16.0) = 234.14 grams (1 mole/234.14g); 234.14(76.44) = 17,897.66 grams About 17,897.66 grams of fertilizer can be made.

Which has more mass: 100 hydrogen atoms, 4 sulfur atoms, or 1 lanthanum (La) atom?

H: 1.01(100) = 101 amu S: 4(32.1) = 128.4 amu La: 1(138.9) = 138.9 amu 1 Lanthanum atom has the most mass of the above listed atoms.

Balance the following equation: HCl (aq) + Zn (s) →ZnCl_2 (aq) + H_2 (g).

H=/H_2 <--Should be 2H, not H Cl=/Cl_2 <--Should be 2Cl, not Cl Zn=Zn Balanced equation: 2HCl (aq) + Zn (s) → ZnCl_2 (aq) + H_2 (g).

Freon, a very useful refrigerant, is produced in the following reaction: 3CCl4 (g) + 2SbF3 (s) → 3CCl2F2 (g) + 2SbCl3 (s) Freon If a chemist wants to make 1.5 x 10^4 moles of Freon using excess carbon tetrachloride, how many moles of antimony trifluoride will the chemist need?

Mole ratio of Freon to carbon tetrachloride to antimony trifluoride = 3:3:2; thus, if 1.5 x 104 moles of Freon are being made, then 1.5 x 104 moles of carbon tetrachloride will be needed as well. carbon tetrachloride ratios = antimony trifluoride 3/(1.5 x 10^4 moles)=2/x 3x=2(1.5 x 10^4 moles) 3x=30000 moles x=30000/3 X = 10,000 moles 1.0 x 10^4 moles of antimony trifluoride will be needed by the chemist.

What is the difference between molecular formulas and empirical formulas?

Molecular formulas give the number of each type of atom in a molecule, whereas, empirical formulas give a simple, whole number ratio of the atoms in a molecule.

Which of the following molecules are covalent? a. SO_3 b. P_2H_6 c. CaSO_4 d. KF

Molecules are covalent if their atoms are only nonmetals. Thus, option A and B are covalent.

In an automobile, nitrogen from the air reacts with oxygen in the engine to make nitrogen monoxide, a toxic pollutant. Write the balanced chemical equation for this reaction.

N=N_2 Monoxide=O_2 Balanced chemical equation: N_2 (g) + O_2 (g) → 2NO (g).

List the chemical formula (including charge) for following ion: ammonium.

NH_4^+

List the chemical formula (including charge) for following ion: nitrite.

NO_2^-

If a substance has 15 positive charges and 11 negative charges, is it positively charged, negatively charged, or neutral?

If a substance has 15 positive charges and 11 negative charges, it is positively charged, because the number of positive charges is larger than the number of negative charges.

If an atom absorbs energy, what happens to its electrons?

If an atom absorbs energy, its electrons will jump to a different orbital--farther away from the nucleus--that has a higher energy level.

How can you determine whether an atom is a metal or a nonmetal from the periodic chart?

If an atom is a metal, it will be on the left side of the jagged line on the periodic table (with the exception of Hydrogen, a nonmetal on the left side of the periodic table). All metal atoms will be on the left side of the jagged line on the periodic table (with the exception of Hydrogen, a nonmetal on the left side of the periodic table).

If the atom is emitting light, what are its electrons doing?

If an atom is emitting light, its electrons are "de-exciting" or releasing their energy as the jump to a lower energy orbital.

If an object has a volume of 63.7 mL, how many kL of space does it occupy?

If an object has a volume of 63.7 mL, it occupies .0000637 kL of space. "Milli" means ".001". 63.7 mL times by ".001" is .0637 L. "Kilo" means "1,000". ".0637" L divided by 1,000 is ".0000637" kL.

If light has a frequency of 2.1 x 1014 Hz, what is its wavelength?

If light had a frequency of 2.1 x 10^14 Hz, its wavelength will be about 1.4 x 10^-6 m. f=c/h 2.1 x 10^14 Hz = (3.0 x 10^8 m/s)/h

P_P=XP_T SO_2: .36(1.1 atm) = .396 atm NO: .58(1.1 atm) = .638 atm SO_3: .05(1.1 atm) = .055 atm The partial pressure of SO_2 is .396 atm. The partial pressure of NO is .638 atm. The partial pressure of SO_3 is .055 atm.

If the total pressure of the gas mixture in P5 above was 1.1 atm, what was the partial pressure of each gas?

-324 J = -.324 kJ Spontaneous: ΔG < 0 ΔG = ΔH - T(ΔS) 0 > -1023 - T(-.324) +1023 1023 > .324T .324 T > 3157.4 K The temperature (T) range for which this reaction is spontaneous is T > 3157.4 K.

If the ∆H of a certain reaction is -1023 kJ/mole and the ∆S is -324 J/mol•K, what is the temperature range for which this reaction is spontaneous?

If two different atoms are bonded together with a purely covalent bond, what can we say about the electronegativities of the two atoms?

If two different atoms are bonded together with a purely covalent bond, we can say the electronegativities of the two atoms are the same. In covalent bonds, the electrons are shared equally. Electronegativity refers to the strength of the atoms to pull away electrons. Thus, if neither of the two different atoms are gaining or losing any electrons (because the bond is covalent), then the electronegativities of the two atoms must be the same.

If two electrically charged particles repel one another, what can we conclude about their charges?

If two electrically charged particles repel one another, we can conclude that they have like charges--either both have a positive charge or both have a negative charge.

The solubility of gases decreases as temperature increases. Carbon dioxide is released from soda when it is heated. Thus, when a glass of soda sits on the counter, it is heated to room temperature--which releases the carbon dioxide and makes it "flatter".

If you have an open glass of soda pop sitting on the counter, it gets "flatter" than the same open glass of soda pop that sits in the refrigerator. Why?

Entropy increases as temperature increases. Thus, the block of copper that is 60 oC has more entropy.

If you have two 50.0 kg blocks of copper, and one is at a temperature of 60 oC while the other is at a temperature of 35 oC, which has more entropy?

NaCl = Na^+ + Cl^- = 2 ions ΔT = -i(K_f)m -15 = -2(1.86)m (-15 = -3.72m)/-3.72 m = 4.03 The molality of the salt solution must be 4.03m.

If you want to lower water's freezing point 15 oC by adding NaCl, what must the molality of the salt solution be (Kf for water is 1.86 oC/m)?

Name the following ion: NO_3 ^-.

Nitrate

What element makes up the majority of the air we exhale?

Nitrogen

What element makes up the majority of the air we inhale?

Nitrogen

What is the chemical formula for nitrogen monoxide?

Nitrogen = N Mono- = 1 Oxide = Oxygen = O NO

N_2 + 3H_2 --> 2NH_3 How many grams of nitrogen are needed to react with 5.30 moles of H_2?

Nitrogen gas: H_2 => 1 N_2: 3 H_2 About 1.77 moles of nitrogen are needed to react with 5.30 moles of H_2. 14.0g of N_2 = 1 moles of nitrogen 14.0(2) = 28.0 28.0(1.77) = 49.6g About 49.6g

Can an element undergo a decomposition reaction?

No, because a decomposition reaction breaks a compound down into its elements.

Is the following equation balanced; Explain: CaF_2 (aq) + 2NH_4Cl (aq) → CaCl_2 (aq) + NH_4F (aq).

No: 1Ca=1Ca F_2=/F <--Should be 2F, not F 2N=/N <--Should be 2N, not N 2H_4=/H_4 <--Should be 2H_4, not H_4 2Cl=Cl_2 The balanced equation should be: CaF_2 (aq) + 2NH_4Cl (aq) → CaCl_2 (aq) + 2NH_4F (aq).

Identify the following as metal or nonmetal (do not use other names): I.

Nonmetal

Identify the following as metal or nonmetal (do not use other names): N.

Nonmetal

4 Al + 3 O2 -> 2 Al2O3 How many moles of oxygen are required to react with 15.3 moles of Al?

O to Al mole ratio = 6:4 6/x=4/(15.3) 91.8=4x x=(91.8)/4 X = 22.95 Thus, about 23.0 moles of oxygen are required.

List the chemical formula (including charge) for following ion: hydroxide.

OH^-

List the chemical formula (including charge) for following ion: oxide.

O^(2-)

What is the chemical formula of oxygen gas?

O_2 (g)

Why do oil and water not mix?

Oil and water do not mix due to their molecular structure. Water is a polar covalent compound, whereas, oil is a nonpolar (or purely) covalent compound. Thus, water has an electrical charge, but oil does not have an electrical charge. Therefore, due to the differences is charges, oil and water do not mix.

Draw a Lewis structure for PCl3

One P with 1 pair of valence electrons bonded each to three Cl's with three pairs of valence electrons each

H2O2 = 2(1.01) + 2(16) = 34.02 g/mol 1600/(34.02) = 47.03 moles Mole ratio of H2O2 to water vapor = 7:8 Kelvin = oC + 273.15K 540 oC = 813.15K PV = nRT, where R = .0821 1.2V = 47.03(813.15)(.0821) 1.2V = 3139.7 V = 2616.4 The volume of water vapor that will be produced is 2616.4 L.

One common rocket engine uses the following reaction: 7H2O2 (aq) + N2H4 (g) →2HNO3 (g) + 8H2O (g) If the rocket engine contains 1600.0 grams of H2O2 and an excess of N2H4, what volume of water vapor will be produced when the rocket fires up to a temperature of 540 oC and a pressure of 1.2 atm?

When measuring any matter, you should always go...

One digit further than the instrument allows

PbCl2 = 207.2 + 2(35.5) = 278.2g (278.2)/1=30/m (278.2m=30)/278.2 Moles = .108 Molarity = (#moles)/(#liters)=(.108moles)/(1.6L)=.067M The molarity of the Pb2+ in the water would be about .07M.

One popular test for lead (Pb2+) contamination in drinking water is the "chloride test." This test involves adding NaCl to water. Any Pb2+ in the water will immediately react with the Cl-, forming a solid precipitate: Pb2+ (aq) + 2NaCl (aq) → PbCl2 (s) + 2Na+ (aq) Measuring the mass of this precipitate can tell you what concentration of Pb2+ is in the water. If an excess of NaCl is added to 1.6 liters of water and 30.0 grams of PbCl2 are produced, what was the molarity of Pb2+ in the water?

Name the compound: P_2H_6.

P = Phosphorus H = Hydrogen 2 = Di- 6 = Hexa- Diphosphorus Hexahydride

Classify the following as either a mixture or a pure substance and then as an element, compound, homogeneous mixture, or heterogeneous mixture: HNO_3.

Pure Substance; Compound

Classify the following as either a mixture or a pure substance and then as an element, compound, homogeneous mixture, or heterogeneous mixture: Gold Ingot.

Pure Substance; Element

If you wanted to protect water from freezing, a compound you would use as a solute would need to be exothermic. Exothermic processes release heat. All the compounds are soluble salts, but since Al(NO3)_3 divides into the most ions, it would heat the water the most.

If you wanted to protect water from freezing, which compound below would accomplish this best. Explain. NaNO3, Mg(NO3)2, or Al(NO3)3

A calorimeter is filled with 250.0 g of water at 24.6 degrees C. A 60.0 g sample of a metal at 100.0 degrees C is dropped in this calorimeter and causes the temperature to increase a total of 4.5 degrees C. What is the specific heat of the metal (in J/g°C)? Ignore the calorimeter in this problem.

Ignore to calorimeter = q_calorimeter=0 -q_metal=q_water + q_calorimeter q=m∙c(J/(g ∙ degrees C))∙∆T ∆T=T_Final-T_Initial q_water=250.0 g ∙4.184(J/(g ∙ degrees C))∙([24.6+4.5]℃-24.6℃) q_water=1046.0∙(29.1℃-24.6℃) q_water=4707.0 J -q_metal=q_water + q_calorimeter -q_metal=4707.0 J+0 q_metal=-4707.0 J q=m∙c(J/(g ∙ degrees C))∙∆T -4707.0 J=60.0 g∙c(J/(g ∙ degrees C))∙(29.1℃-100.0℃) -4707.0 J=-4254.0∙c(J/(g ∙ degrees C)) (-4707.0 J)/(-4254.0)=c(J/(g ∙ degrees C)) c≈1.1(J/(g⋅℃)) The specific heat of the metal is about 1.1 (J/(g⋅℃)).

Kinetic energy is in the substances themselves in a chemical reaction, and thus, this energy is active in releasing or absorbing energy during a reaction.

In a chemical reaction, where is the kinetic energy?

The potential energy is stored in the chemical bonds of a substance.

In a chemical reaction, where is the potential energy?

What is the main difference between a chemical change and a physical change?

In a physical change the atoms and/or molecules in a substance are not altered, whereas, in a chemical change, the atoms and/or molecules are affected.

In a titration, the endpoint signifies when the acid and base have completely reacted with one each other to the point where no more of either acid or base need be used.

In a titration, what is the significance of the endpoint?

1) It reveals whether a substance is an acid or base based off its pH. 2) It also helps to determine the end-point of titration.

In acid/base chemistry, what two uses does an indicator serve?

P_(Water Vapor) = 26.7 torr P_T=P_(CO_2 )+P_(Water Vapor) 878 torr = P_(CO_2 ) + 26.7 torr -26.7 P_(CO_2 ) = 851.3 torr The pressure of the carbon dioxide in the vessel would be about 851.3 torr.

In an experiment similar to Experiment 6.1, a chemist collects carbon dioxide over water at 27oC. If the gas in the collection vessel has a pressure of 878 torr, what is the pressure of carbon dioxide in the vessel?

Explain VSEPR theory in your own words.

In my own words, the VSEPR theory states that molecules will form whatever shape keeps the valence electrons of the central atom farthest apart.

Endothermic

Is the following diagram an endothermic or exothermic reaction?

Use Table 13.3 and 13.4 ΔSº = ΣSº (products) - ΣSº (reactants) ΔSº = (6[161]) - (2[49]+0+0) ΔSº = 868 ΔHº = ΣHº (products) - ΣHº (reactants) ΔHº = (6[-278]) - (2[49]+0+0) ΔHº = -1766 Spontaneous: ΔG < 0 ΔG = ΔH - T(ΔS) 0 > -1766 - 298(868) 0 > -260430 The above reaction is spontaneous at 298K.

Is the following reaction spontaneous at 298 K? 2C6H6 (l) + 12H2 (g) + 3O2 (g) → 6C2H6O (l)

Why is it so hard to separate one isotope from another?

It is so hard to separate one isotope from another, because they behave identically in their chemistry.

Name the compound: KF.

K = Potassium F = Fluoride Potassium Fluoride

A chemist experiments with the following reaction: 14HCl + K2Cr2O7 → 2KCl + 2CrCl3 + 3Cl2 + 7H2O If the chemist adds 16 moles of HCl to 1 mole of K2Cr2O7, what is the limiting reactant?

K2Cr2O7

A sample is analyzed as containing 24.09 grams of potassium, 0.308 moles of manganese, and 7.42 x 10^23 atoms of oxygen. What is the empirical formula?

K: 24.09G; 39.1 g/mole, so 24.09/39.1 = .616 moles Mn: .308 moles O: 7.42 x 10^23 atoms ((given # of atoms)/1) x (moles/ avogadro's #) = ((7.42 x 10^23 atoms)/1) x (moles/(6.02 x 10^23 atoms) = 1.233 moles Common Factor = .308 .616/.308 = 2 .308/.308 = 1 1.233/.308 = 4 Mole ratio of K to Mn to O = 2:1:4 The empirical formula, thus, is K2MnO4.

Give the chemical formulas for the following molecules: magnesium oxide.

Magnesium = Mg^(2+) Oxide = O^(2-) Same numerical values, so the subscripts are one and can be ignored. MgO

Find the missing information: Symbol, Name, Metal or Nonmetal, At #, and At Mass #. Mg ________________ ________ ___ ______ ___ Chlorine ______________ ___ ______ ____ _______ ________ 82 _______ ____ _______ ________ 79 ______ ____ Cesium ________ ____ _______ S ________ ______________ ___ _____ Li __________ ________ __ ______ __ Phosphorus ______________ __ _____ __ ____________ ______________ 8 _____ __ ______________ ______________ 1 _____

Magnesium, Metal, 12, 24.3 Cl, Nonmetal, 17, 35.5 Pb, Lead, Metal, 207.2 Au, Gold, Metal, 197.0 Cs, Metal, 55, 132.9 Sulfur, Nonmetal, 16, 32.1 Lithium, Metal, 3, 6.94 P, Nonmetal, 15, 31.0 O, Oxygen, Nonmetal, 16.0 H, Hydrogen, Nonmetal, 1.01

In making calcium nitride, 100.0 grams of calcium plus 100.0 grams of nitrogen makes 152.5 grams of product along with some leftover nitrogen. How much nitrogen should be added in order to make 1.5 kg of calcium nitride without any leftovers? How much calcium should be added in order to make 1.5 kg of calcium nitride without any leftovers?

Mass before reaction = mass after reaction 100.0g + 100.0g = 152.5g + leftover nitrogen 200.0g = 152.5g + leftover nitrogen 47.5g = leftover nitrogen 100.0g - 47.5g = 52.5g used/100.0g of calcium 1.5kg x 1000 = 1500g 100.0gx + 52.5gx = 15000g 152.5gx = 1500g 1500g/152.5g = x x ~~ 9.8 52.5g (9.8) = 514.5g of nitrogen 100.0g (9.8) = 980.0g of calcium

In an experiment to make hydrogen peroxide, a chemist mixes 25.0 grams of hydrogen with 25.0 grams of oxygen. She finds that 28.2 grams of hydrogen peroxide are produced. In addition, there is a lot of hydrogen left over at the end of the experiment. How many grams of hydrogen should have been added to the 25.0 grams of oxygen so that there would be no leftovers at the end of the experiment?

Mass before reaction = mass after reaction 25.0g + 25.0g = 28.2g + leftover Hydrogen 50.0g = 28.2g + leftover Hydrogen 21.8g = leftover Hydrogen 25.0g - 21.8g = 3.2g used/ 25.0 g O 3.2g of H

Lead has a density of 11.4 grams per mL. If I make a statue out of 3.65 L of lead, what is the statue's mass?

Mass equals density times volume. Density equals 11.4 g/mL. Volume equals 3.65 L, which is 3650 mL. Mass is 11.4 times 3650--which is 41610.0 mL, the statues mass. Thus, the statue's mass is 4.161 mL x 10^4.

Identify the following as metal or nonmetal (do not use other names): Re.

Metal

Identify the following as metal or nonmetal (do not use other names): Y.

Metal

What are the three physical characteristics that distinguish metals from nonmetals?

Metals are shapeable, have luster, and conduct electricity--nonmetals have none of these things.

Name these ionic compounds: MgBr2.

Mg = Mg^(2+) as an ionic compound; Mg is a cation, so its name is Magnesium. Br = Br^- as an ionic compound; Br is an anion, so add "ide" as a suffix to its name. Magnesium bromide

Name these ionic compounds: MgCl2.

Mg = Mg^(2+) as an ionic compound; Mg is a cation, so its name is Magnesium. Cl = 〖Cl〗^- as an ionic compound; Cl is an anion, so add "ide" as a suffix to its name. Magnesium chloride

If a substance can be physically separated into its components, is it a pure substance or a mixture?

Mixture

Classify the following as either a mixture or a pure substance and then as an element, compound, homogeneous mixture, or heterogeneous mixture: Egg.

Mixture; Heterogeneous

Classify the following as either a mixture or a pure substance and then as an element, compound, homogeneous mixture, or heterogeneous mixture: Lemonade.

Mixture; Homogeneous

(#moles)/(#liters)

Molarity equation:

4 Al + 3 O2 -> 2 Al2O3 How many grams of Al are needed to produce 0.75 moles of Al2O3?

Mole ratio of Al to Al2O3 = 4:2 .75/2 = .375 4(.375) = 1.5 1.5 moles of Al are needed Moles = grams/(# of atoms x atomic weight) 1.5 = g/(27.0) (1.5 = g/(27.0)) 27.0 40.5 = g 40.5 grams of Al are needed.

4 Al + 3 O2 -> 2 Al2O3 How many moles of Al2O3 are formed when 0.85 moles O2 reacts with Al?

Mole ratio of Al2O3 to O2 = 2:6 6/(.85)=2/x 6x=1.7 x=(1.7)/6 X = .28333... About .28 moles of Al2O3 are formed.

A compound has a molecular formula of H3PO4. What is its empirical formula?

Ratio = 3:1:4 No common factor, so this is the empirical formula. Therefore, the empirical formula is H3PO4.

A compound has a molecular formula of C7H14O7. What is its empirical formula?

Ratio = 7:14:7 Common factor is 7, so divide the ratio by 7 to get 1:2:1. Therefore, the empirical formula is CH2O.

4 Al + 3 O2 -> 2 Al2O3 How many moles of Al are needed to react with 6.4 grams of O2?

Ratio of moles of Al to O2 = 4:6 Convert that to grams using Moles = grams/(# of atoms x atomic weight) Al: 4=g/((27.0)) => (4=g/((27.0)))27.0 => g = 108.0 O2: 6=g/(2 x 16.0) => (6=g/(32.0))32.0 => g = 192.0 Ratio of Al to O2 in grams = 108.0:192.0 6.4/192.0 = (.1)/3 (.1)/3(108.0) = 3.6 grams of Al are needed Moles = grams/(# of atoms x atomic weight) => moles = (3.6)/((27.0)) => about .1333... moles About .13 moles of Al are needed.

Silver tarnishes when exposed to oxygen and dihydrogen monosulfide. The chemical reaction is as follows: 4Ag (s) + 2H2S (g) + O2 →2Ag2S (s) + 2H2O (l) silver tarnish Every household has some H2S in the air (it smells like rotting eggs), but there is usually only a small quantity. Thus, H2S is almost always the limiting reactant in this reaction. If a silver spoon has 0.0023 moles of tarnish on it, how many moles of H2S was it exposed to?

Ratio of moles of H2S to Ag2S = 2:2 Thus, .0023 moles of tarnish will require .0023 moles of H2S.

Liquid octene, C_8H_16, can react with gaseous hydrogen to make liquid octane, C_8H_18. Write the balanced chemical equation for this reaction.

Reactant: Liquid octene = C_8H_16 (l) Reactant: gaseous hydrogen = H_2 (g) Product: liquid octane = C_8H_18 (l) Balanced Chemical Equation: C_8H_16 (l) + H_2 (g) → C_8H_18 (l).

Moles of silver to moles of hydrogen sulfide to tarnish = 4:2:2, or 2:1:1 Ag = 107.9 g/mol Kelvin = oC + 273.15, so 22 oC = 295.15K 65.7 mL = .0657 L PV = nRT, where R = .0821 1.23(.0657) = n(.0821)295.15 .0808 = 24.2318n n = .0033 moles of H2S (.0033 moles of H2S )/1=(2 moles of Ag)/(1 moles of H2S)=(.0033)(2)= .0067 moles of Ag .0067(107.9) = .72 g About .72 grams of silver on the spoon will tarnish.

Silver tarnishes in the presence of oxygen and hydrogen sulfide according to the following equation: 4Ag (s) + 2H2S (g) + O2 (g) →2Ag2S (s) + 2H2O (l) tarnish Usually, H2S is the limiting reactant. If a silver spoon is placed in a container that holds 65.7 mL of H2S at 1.23 atm and 22oC, how many grams of silver on the spoon will tarnish?

A compound has an empirical formula of CHBr2. If its molar mass is 345.6 grams, what is its molecular formula?

So CHBr2 must be 345.6 grams. Mole ratios of C to H to Br = 1:1:1 C = 12.0 H = 1.01 Br2 = 2(79.9) = 172.81 2(172.81) = 345.6 Thus, the molecular formula is C2H2Br4.

∆Ho = ∑∆Hfo (products)-∑∆Hfo (reactants) ∆Ho = (2[-45.9]+4[-242]) - (2[33.2]+0) ∆Ho = -1126.2 kJ 55g of NH3 is about 3.2 moles. 17.03g/mol 3.2(-1126.2 kJ) = -3603.84 kJ -3603.84 kJ/ 2 moles = -1801.92 kJ -1801.92 kJ of energy will be released if 55 g of NH3 are formed.

Suppose you synthesized ammonia with the following reaction: 2NO2 (g) + 7H2 (g) →2NH3 (g) + 4H2O (g) How much energy will be released if 55.0 g of NH3 are formed?

What is the chemical formula for tetranitrogen hexahydride?

Tetra- = 4 Nitrogen = N Hexa- = 6 Hydride = Hydrogen = H N_4H_6

Use table 13.2 to find the bond energies Cl-Cl = 240 kJ; 2Cl2 = 2(240) = 480 kJ H-O-H = 459 kJ; 2H2O = 4(459) = 1839 kJ H-Cl = 428 kJ; 4(428) = 1712 kJ O_=O = 494 kJ ∆Ho = ∑〖bond energy〗 (products)-∑〖bond energy〗 (reactants) ∆Ho = (1712+494)-(480+1839) ∆Ho = -113 The ∆H of this reaction is -113 kJ.

The "chlorine smell" of pool water is not, in fact, due to chlorine. When chlorine hits water, some of it reacts with the water in the following way: 2Cl2 + 2H2O →4HCl + O2 The smell you get from a chlorinated pool is often the smell of the HCl produced in this reaction. What is the ∆H of this reaction?

Write the Law of Mass Conservation in your own words.

The Law of Mass Conservation states that matter can be neither destroyed nor created, so matter can only change forms and cannot be lost or gained in a chemical reaction.

What law did Dalton predict using his theory?

The Law of Multiple Proportions

What two laws were instrumental in the development of Dalton's atomic theory?

The Laws of Mass Conservation and Definite Proportions

What do the following things have in common? 32.1 g of sulfur, 40.1 g of calcium, and 60.1 g of SiO_2

The above elements and compound all have 1 mole of their substance.

Pressure

The amount of force per amount of area put on an object

Answer the picture question.

The answer is...B.

Order the following in terms of increasing atomic radius: As, K, Br, Se.

The atomic radii of atoms increase from right to left and from top to bottom on the periodic table, in general. Thus, from having the lowest radius to the largest, the atoms above would be ordered as follows: Br, Se, As, and K.

Name the compound: (NH_4)_2O.

The chemical formula of a compound is made by dropping the signs and switching the numbers of the individual elements' formulas. To find whether each element is positive or negative, we have to consult the periodic table. So NH_4 would stay the same, but the 2 outside the parentheses would be the charge of O. Since the O does not have a subscript, the NH_4 will have a charge of 1. NH_4 is ammonium, so it has a positive charge. O is oxygen, so it has a negative charge. Therefore, the deconstructed chemical formula would be NH_4^+ + O^(2-). In words, this would be Ammonium Oxide.

Two light bulbs emit light of the same color. One, however, is much brighter than the other. What can you say about the wavelengths and amplitudes of the waves being emitted by each bulb?

The light bulb emitting brighter light is going to have a larger amplitude than the other light bulb, because the larger the amplitude is, the bigger and brighter the wave of light is. Since the light bulbs are emitting the same color, their wavelengths will be equal.

A man pushes a stalled car for 2 minutes. During the first 1.5 minutes, the car does not move, but for the last 0.5 minutes the man pushes even harder and succeeds in getting the car to move. Is the man doing work for the entire 2 minutes? If not, does he ever succeed in doing work? If so, when?

The man is not doing work for the entire 2 minutes. He is only doing work in the last half minute. In the first minute-and-a-half, the car does not move at all, and in order for work to be done, movement must occur. However, in the last half-minute, the car moves, so work occurs.

#molecules/(6.02 x 1023) = 1,000/(6.02 x 1023) = 1.66 x 10-21 Mole fraction = X = .87 = (#moles in compound)/(total #moles in mixture) = ((total #moles in mixture))/(1.66 x 10-21) .87(1.66 x 10-21) = total #moles in mixture total #moles in mixture = 1.45 x 10-21 1.45 x 10-21(6.02 x 10^23) = 870 870 molecules of the compressed air will be nitrogen molecules.

The mole fraction of nitrogen gas in compressed air is 0.87. If you have 1,000 molecules of compressed air, how many will be nitrogen molecules?

If you have an orange light bulb and a violet one, Which emits waves with the largest wavelength?

The orange light bulb will emit waves with the largest wavelength over the violet light bulb.

What were the differences between the plum pudding model of the atom and the planetary model of the atom?

The plum pudding model of an atom featured a positively charged pudding-like substance in which electrons were suspended in. This pudding-like substance made up the sphere shape of the atom. On the other hand, in the planetary model of the atom, protons are in the nucleus of the atom (in the center), and electrons orbit around the cluster of protons. In this model, there is no pudding-like substance, and the electrons orbit around the protons--they are not suspended in a pudding-like substance.

In the metric system, what does the prefix "milli" mean?

The prefix "milli" means one-thousandth or ".001".

Where do the protons and neutrons exist in an atom?

The protons and neutrons exist in the nucleus (center) of an atom.

One electron is in a 2p orbital while another is in a 3s orbital. What shape is each electron's orbit?

The shape of the electron's orbit in the 2p orbital is somewhat like a dumbbell, and the shape of the electron's orbit in the 3s orbital is somewhat spherical.

The temperature of deep space is 3.5 K. What is the temperature of deep space in Fahrenheit?

The temperature of deep space in degrees F is -453.4 degrees F. The temperature of deep space in C is -269.65 degrees C. The formula for this conversion is as follows: (degrees F -32)/1.80 = degrees C.

If the temperature of deep space is 3.5 K, what is the temperature of deep space in Celsius?

The temperature of deep space is Celsius is -269.7 ºC. Kelvin equals Celsius plus 273.15. Thus, 3.5 equals Celsius plus 273.15; so, 3.5 minus 273.15 equals -269.65, so -269.7 ºC.

A chemist watches the temperature of a vat of liquid and notices that it decreases over time. What can the chemist conclude about the energy in the vat from this observation?

The vat is being released. In other words, the liquid is losing energy.

If you have an orange light bulb and a violet one, Which emits light of higher frequency?

The violet light bulb will emit light of higher frequency than an orange light bulb.

If you have an orange light bulb and a violet one, Which emits the higher energy light?

The violet light bulb will emit the higher energy light than an orange light bulb.

What are valence electrons and why are they so important in chemistry?

Valence electrons are electrons in an atom that exist at the highest energy level and are farthest from an atom's nucleus. These electrons are so important in chemistry, because they determine an atom's chemical behavior and chemistry.

What makes water an exception to the phase change rule?

Water is less dense as a solid than it is as a liquid. Thus, the molecules are slower and closer together when water is in its liquid phase than when it is in its solid phase--when it expands.

What do we call the experimental apparatus that William Crookes used in his experiments, and what did he discover with it?

We call the experimental apparatus that William Crookes used in his experiments a Crookes tube (also referred to as a cathode ray tube). Crookes was able to use his Crookes tube to discover that cathode rays were particles.

The properties of an ideal gas are that the atoms or molecules that compose the gas are very little compared to the volume of the amount of the gas available, that they are far enough apart from one another to not face repulsion or attraction, and that their collisions are elastic--meaning, there is no lost energy in the collision.

What are the properties of an ideal gas?

1) Pa 2) Atm 3) mmHg

What are the three units used to measure pressure?

The general rule a careful scientist must follow when extrapolating data is to ensure there is a lot of data establishing the trend and to extrapolate as little as necessary.

What general rule must a careful scientist follow when extrapolating data?

a solution where the max amount of solute that can be dissolved is dissolved.

What is a saturated solution?

a quantity measured in which how it got to its final destination does not matter, only what the final destination is

What is a state function?

Standard temperature is 273K, and standard pressure is 1.000 atm.

What is standard temperature and pressure?

ZnCl_2=Zn^(2+)+Cl_2^(1-)=3 ions=65.4+2(35.5)=136.4g/mole 100/136.4 = .73 moles 700g=.7kg Molality = (#moles of solute)/(#kg of solvent)=(.73)/(.7)=1.05 ΔT = i(K_b)m ΔT = 3(.512)1.05 ΔT = 1.613 100 + 1.61 = 101.61 The boiling point of this solution would be 101.61ºC.

What is the boiling point of a solution made by mixing 100.0 g ZnCl2 with 700.0 grams of water (Kb for water is 0.512oC/m)?

Molality is: The number of moles of solute per kilogram of solvent. Molarity is: The number of moles of solute per liter of solution.

What is the difference between molality and molarity?

N^(-3)+H_3^+=1 ion= NH3 = 14 + 3(1.01) = 17.03g/mole 30/17.03 = 1.76 moles 300g = .3kg Molality = (#moles of solute)/(#kg of solvent) = (1.76)/(.3)=5.87 ΔT = -i(K_f)m ΔT = -1(1.86)5.87 ΔT = -10.92 The freezing point of this solution would be -10.9ºC.

What is the freezing point of a solution made by mixing 30.0 grams of NH3 with 300.0 grams of water (Kf for water is 1.86 oC/m)?

M_1 V_1=M_2 V_2 35(.010) = 30M_2 (.35 = 30M_2)/30 M_2 = .012 The molarity of a solution of hydroiodic acid if exactly 35mL of .010M lithium hydroxide is required to titrate 30mL of the acid solution to the equivalence point would be .012M.

What is the molarity of a solution of hydroiodic acid if exactly 35.0 mL of 0.010 M lithium hydroxide is required to titrate 30.0 mL of the acid solution to the equivalence point?

The side of the reaction that contains the most molecules in the gas phase is the reactant side of the reaction. Thus, the chemicals go from higher entropy to lower entropy, so the ΔS is negative.

What is the sign of ∆S for the following reactions? Explain why. HCl (g) + NH4OH (g) →NH4Cl (s) + H2O (l)

The side of the reaction with the most molecules in the gas phase has the highest entropy--which happens to be on the product side. Thus, the chemicals go from lower entropy to higher entropy, so the ΔS is positive.

What is the sign of ∆S for the following reactions? Explain why. NaHCO3 (aq) + HCl (aq) →NaCl (aq) + H2O (l) + CO2 (g)

Given all the substances are gases, the side of the reaction with the most atoms or molecules will have the highest entropy. On the reactant side, there are 4 molecules, and on the product side, there are 2 molecules. Thus, the chemicals go from higher entropy to lower, so the ΔS is negative.

What is the sign of ∆S for the following reactions? Explain why. SO2 (g) + 3F2 (g) →SF6 (g) + O2 (g)

PV = nRT, where R = .0821 Kelvin = oC + 273.15; 25 oC = 298.15K Chlorine Gas = Cl_2=2(35.5)=71g/mol mol=(11.6)/71= .16 moles=n 1(V) = .16(.0821)298.15 V = 4.00 L The volume is 4.00 Liters.

What is the volume of 11.6 grams of chlorine gas at 1.00 atm and 25 degrees C?

∆H = products - reactants ∆H = 70 kJ - 18 kJ = 52 kJ The ∆H of that reaction is 52 kJ.

What is the ∆H of the reaction if we assume the product line is at 70 and the reaction line is at 18?

Use Table 13.4 ΔSº = ΣSº (products) - ΣSº (reactants) ΔSº = (76.1) - (69.9 + 38.2) ΔSº = -32 kJ The ΔSº of the above reaction is -32 kJ.

What is the ∆So of the following reaction? H2O (l) + CaO (s) →Ca(OH)2 (s)

The kind of solute that dissolves best under high pressure conditions would be gas.

What kind of solute (solid, liquid, or gas) dissolves best under high pressure conditions?

The kind of solute that dissolves best under high temperature conditions would be a solid

What kind of solute (solid, liquid, or gas) dissolves best under high temperature conditions?

The kind of solute that has a solubility least affected by the conditions under which the solution is made would be a liquid.

What kind of solute (solid, liquid, or gas) has a solubility that is least affected by the conditions under which the solution is made?

HBr + H_2 O --> H_3 O+Br

When HBr is mixed with water, what chemical reaction occurs? Give the balanced chemical equation.

Use table 13.3 for ∆Hfo s ∆Ho = ∑∆Hfo (products)-∑∆Hfo (reactants) ∆Hfo = (-198kJ-(2 mol)(-396 kJ/mol))/(-2 mol) ∆Hfo = 594/(-2) ∆Hfo of SO_2 = -297 kJ The ∆Hfo of SO2 (g) is -297 kJ/mole.

When coal is burned in a power plant, it usually contains a small amount of sulfur contamination. The sulfur burns along with the coal to make SO2. This sulfur dioxide then begins to travel up the smokestack, where it reacts with oxygen as follows: 2SO2 (g) + O2 (g) → 2SO3 (g) If the ∆Ho of this reaction is -198 kJ, what is the ∆Hfo of SO2 (g)?

Acid + Base --> Salt + Water Al_2 (CO_3 )_3+H_2 O → H_2 O+Al_2 (CO_3 )_3 Al_2 (CO_3 )_3) Drop the signs and switch the numbers Al has a charge of 3. (CO_3 ) has a charge of 2. Al^(+3) and CO_3^(-2) It forms two Al^(+3) and three CO_3^(-2) ions.

When the compound Al2(C03)3 dissolves in water, what ions does it form and how many of each ion are present?

Salt is the solute, and water is the solvent.

When you dissolve salt in water, which compound is the solute and which is the solvent?

That fact does not contradict the Second Law of Thermodynamics, because it does not include the whole process. The neurons do not only store information in an orderly fashion, they do other things as well, and the brain does other things too. Therefore, there is some disorder in the brain, meaning there is entropy of at least 0, so the Second Law of Thermodynamics is not contradicted.

When you study, your brain neurons store information. This causes the brain to become more ordered. Why doesn't that fact contradict the Second Law of Thermodynamics?

H2C03 and H3P04

Which of the following is (are) polyprotic acid(s)? a. H3P04 b. Ca(0H)2 c. HN03 d. H2C03

The standard enthalpy of formation (ΔH_f) of an element in its element state is 0, so O_2 and Cl_2 have a ∆Hfo of 0. NaOH is not an element. Na (aq) and H_2 (l) are not in their elemental forms, and O (g) does not exist in nature, because it is a diatomic element.

Which of the following substances will have a ∆H^o_f of zero? NaOH (aq), Na+ (aq), O2 (g), O (g), Cl2 (g), H2 (l)

grams/m^3 and moles/mL

Which of the following units could be used as concentration units? a. grams/m^3 b. mL/meters c. moles/mL d. moles/sec e. cups/mi

All of the laws we studied in this module require the use of the Kelvin temperature scale, but Charles's Law directly involves the Kelvin temperature scale.

Which of the laws you studied in this module leads to the Kelvin temperature scale?

Hess's Law states that ∆H is a state function, meaning it is independent of how it got to its final destination. Hess's Law is a more exact way of determining ∆H than the technique that uses bond energies, because the bond energy technique includes all the phases each substance in the reaction has to endure to get to their final destination, unlike Hess's method. In the end, enthalpy of an individual substance cannot be measured, so taking into account the extra phases in not necessary, per say, and is thus, not as exact as simply using the final destination reaction.

Why is Hess's Law a more exact way of determining ∆H than the technique that uses bond energies?

Boyle's Law, in my own words, states the volume and pressure of a gas are inversely-related when there is a constant temperature.

Write Boyle's Law in your own words

How precise can you be with your measurement?

You can only be as precise as the least precise instrument you are using.

Give the abbreviated electron configuration of: zinc

[Ar]4s^2 3d^10

How many electrons are in the valence shell of the atoms: zinc

[Ar]4s^2 3d^10 There are 2 electrons in the valence shell of a zinc atom since the 4s orbital is the last one.

Give the abbreviated electron configurations of the following atoms: V

[Ar]4s^2 3d^3

Define a limiting reactant

a reactant that runs out before any other reactants in a chemical reaction--thus, it also determines how much of a given substance(s) is produced through the reaction.

Sublimation occurs when what happens?

a solid changes directly into a gas, without passing through a liquid phase

Which of the following is not a complete combustion equation? a. H_2CO_3 (s) → CO_2 (g) + H_2O (g) b. 2C_3H_8O + 9O_2 → 6CO_2 + 8H_2O c. CH_4 (g) + 2O_2 (g) → CO_2 (g) + 2H_2O (g)

a. H_2CO_3 (s) → CO_2 (g) + H_2O (g)

What is the difference between an atom and an ion?

atoms have the same number of protons and electrons, whereas, ions are atoms that have gained or lost an electron(s). In other words, atoms are neutral, but ions are atoms with a charge.

Which of the following is not a formation reaction? a. 2H_2 (g) + O_2 (g) → H_2O (g) b. 2S (s) + Cl_2 (g) + 5F_2 (g) → 2SF_5Cl c. H_2CO_3 + 2KOH → 2H_2O + K_2CO_3

c. H_2CO_3 + 2KOH → 2H_2O + K_2CO_3

amphiprotic compounds

compounds that can be an acid or base depending on the situation

If a stoichiometry problem gives you the quantity of a substance in grams, what is the first thing you must do to solve the problem?

convert the grams to moles

What does a catalytic converter do for an automobile?

converts the poisonous carbon monoxide--produced by the burning of fuel in an automobile--into carbon dioxide

What is the fundamental difference between ionic compounds and covalent compounds?

covalent bonds share electrons, but ionic compounds give and take electrons, and ionic compounds form ions, whereas, covalent bonds form molecules.

If a light wave has a wavelength of 251 nm, what is its energy?

f = c/h; E = h x f If a light wave has a length of 251 nm, its energy is about 8.0 x 10^-19 J.

To name an ion, take each element's chemical ___________, ignore the _______, and _________ the numbers.

formula signs switch

What does VSEPR stand for?

VSEPR stands for Valence Shell Electron Pair Repulsion.

Convert 2.10 mL into L.

2.10 mL is .0021 L. "Milli" means ".001". ".001" times "2.1" mL is ".0021" L.

When 2.33 moles of C3H8 burn in excess oxygen, how many moles of CO2 will be formed? Assume this is complete combustion

2.33C3H8 + O2 -> 6.99CO2 + 9.32H2 2.33(3)=6.99 6.99 moles of CO2 will be formed.

Molality = (#moles of solute)/(#kg of solvent) = 50/(3.4)=14.7m The solution's molality is 14.7m.

If a solution is made by mixing 50.0 moles of K0H to 3.4 kilograms of water, what is the solution's molality?

Phosgene, COCl2, was once used as a chemical weapon in war. When humans breathe in the gas, it reacts with the water in their lungs in the following way: COCl2 + H2O → CO2 + 2HCl The product HCl burns the lining in the lungs, making them unable to function. Thus, by breathing in phosgene, a person will eventually suffocate. Assuming that 10.0 grams of HCl in the lungs is deadly, how many grams of phosgene would a person need to breathe in order to die?

HCI = 1.01 + 35.5 = 36.51 g/mole (grams given/1) x (1 mole/grams per mole) = (10.0g/1) x (1 mole/36.51g) = about .27 moles of HCI is 10.0 grams. Mole ratio of phosgene to HCI = 1:2 .27/2 = .14 moles of phosgene would be needed. COCl2 = 12.0 + 16.0 + 2(35.5) = 99.0g/mole x moles = (99.0g)(.14 moles) x = 13.86g About 13.86 grams of phosgene would be needed in order to die.

What makes a chemical equation balanced?

Having an equal number of molecules on the reactant side as on the product side.

The solubility of solids increases as the temperature increases. Thus, the solubility of solids decreases as the temperature decreases. Therefore, if the temperature of a hot tub with dissolved solids decreases, the solubility of those solids will also decrease--making the tub look cloudy and filled with a fine solid.

Hot tubs generally contain water at a temperature of 38 oC. In order to keep the water clean, several solid solutes are dissolved in the water. Many hot tub manufacturers warn that if the water gets too cold, it will get cloudy and filled with a fine solid. Why?

A H^+, or hydrogen ion, is a hydrogen atom that has lost an electron. Hydrogen atoms have one electron and one proton. Thus, if the hydrogen atom becomes a hydrogen ion, it loses its only electron and only has one proton. Therefore, a H^+ is a proton.

How are protons and H^+ ions related?

M_1 V_1=M_2 V_2 .012V_1 = .112(50) (.012V_1 = 5.6)/.012 V_1 = 466.67mL About 466.67mL of .012M barium hydroxide are required to titrate exactly 50mL of a .112M hydrochloric acid solution.

How many milliliters of 0.012 M barium hydroxide are required to titrate exactly 50.0 mL of a 0.112 M hydrochloric acid solution?

M_1 V_1=M_2 V_2 50(.2) = .05V_2 (10 = .05V_2)/.05 V_2 = 200mL 200 - 50 = 150mL 150mL of water would be needed to be added to 50mL of a .2M solution to produce a final molarity of .05M.

How much water would need to be added to 50.0 mL of a 0.200 M solution to produce a final molarity of 0.050 M?

An acid is a molecule that donates H^+ ions, so the molecule that lost a H^+ ion on the product side will be the acid. CH40 is the acid.

Identify the acid in the following reaction: PH3 + CH40 → CH30- + PH4+

Heat is added to two identical objects that are initially at the same temperature. If the first absorbs 100.0 cal and the second absorbs 100.0 J, which gets hotter? Explain.

If 1 calorie = 4.184 Joules, then 100.0 calories equals 418.4 Joules. 418.4 J is hotter than 100.0 J, so 100.0 calories is hotter than 100.0 Joules.

If a chemical reaction has a positive ∆H, the beaker that contains the reaction will feel cold once the reaction is finished.

If a chemical reaction has a positive ∆H, will the beaker that contains the reaction feel hot or cold once the reaction is finished?

If a chemical reaction is exothermic but has a negative ΔS, you could decrease the temperature in order to make it possible to run the reaction. Exothermic is energy releasing, so it causes heat. Since the ΔS is negative, the substance is going from a liquid to a solid, but we want to reverse this to make the ΔS positive, so it is spontaneous. In order to do this, we must decrease the temperature.

If a chemical reaction is exothermic but has a negative ∆S, what could you do to the temperature in order to make it possible to run the reaction? Explain your reasoning.

If a chemist makes a solution in a beaker using water and a solute that dissolves endothermically in water, the chemist would expect the beaker to feel cold, because endothermic processes absorb heat.

If a chemist makes a solution in a beaker using water and a solute that dissolves endothermically in water, would you expect the beaker to feel hot or cold?

If a hot object is totally insulated from the outside world (totally unable to interact with anything else), will its temperature ever be able to change? Explain your answer.

If a hot object is totally insulated from the outside world, its temperature would never be able to change. In order for an objects temperature to increase or decrease, energy must be added for released to/into the object. If the object is totally insulated from the outside world, then it cannot release its energy to cool down, and it cannot gain any energy to heat up further.

If a solid solute is not dissolving well in water, you can increase its solubility by heating the solid and/or the water.

If a solid solute is not dissolving well in water, what can you do to increase its solubility?

CaBr2 = 40.1 + 2(79.9) = 199.9g/mole 35/199.9 = .18 moles 675g = .675kg Molality = (#moles of solute)/(#kg of solvent)=(.18)/(.675)=.27m The solution's molality is .27m.

If a solution is made by mixing 35.0 g of CaBr2 with 675 grams of water, what is the solution's molality?

Name the following ion: PO_4 ^3-.

Phosphate

Classify the following as a physical or chemical change: Kool-Aid powder is dissolved into water.

Physical

Classify the following as a physical or chemical change: vase is smashed into pieces.

Physical

When something is dissolved into water, what kind of change occurs: chemical or physical?

Physical

If a substance can be given a single chemical name, e.g. calcium bromide, is it a pure substance or a mixture?

Pure Substance

Classify the following molecule as ionic, polar covalent, or purely covalent: CF_3Cl.

Polar covalent molecules can only exist between different atoms, and they share their electrons unequally (meaning they have different electronegativities). Also, the bonds cannot pull on the central atom in exactly opposite directions. Purely covalent molecules can only exist between the same type of atoms, and they share their electrons equally (meaning they have the same electronegativities). Also, the electrons must be being pulled in exactly opposite directions. Ionic molecules must be between a metal and nonmetal. C: Nonmetal with electronegativity of 2.5 F: Nonmetal with electronegativity of 4.0 Cl: Nonmetal with electronegativity of 3.0 Since all the atoms that compose this molecule are nonmetals but different atoms, this molecule is polar covalent.

Classify the following molecule as ionic, polar covalent, or purely covalent: CS_2.

Polar covalent molecules can only exist between different atoms, and they share their electrons unequally (meaning they have different electronegativities). Also, the bonds cannot pull on the central atom in exactly opposite directions. Purely covalent molecules can only exist between the same type of atoms, and they share their electrons equally (meaning they have the same electronegativities). Also, the electrons must be being pulled in exactly opposite directions. Ionic molecules must be between a metal and nonmetal. C: Nonmetal with electronegativity of 2.5 S: Nonmetal with electronegativity of 2.5 Since this molecule is composed of atoms with the same electronegativity, all nonmetals, and the surrounding atoms are being pulled on the central atom in exactly opposite directions (due to its linear shape), this molecule is purely covalent.

Classify the following molecule as ionic, polar covalent, or purely covalent: MgCl_2.

Polar covalent molecules can only exist between different atoms, and they share their electrons unequally (meaning they have different electronegativities). Also, the bonds cannot pull on the central atom in exactly opposite directions. Purely covalent molecules can only exist between the same type of atoms, and they share their electrons equally (meaning they have the same electronegativities). Also, the electrons must be being pulled in exactly opposite directions. Ionic molecules must be between a metal and nonmetal. Mg: Metal with electronegativity of 1.2 Cl: Nonmetal with electronegativity of 3.0 Since this molecule is composed of different types of atoms with different electronegativities and the bonds are pulling on the central atom in exactly opposite directions (due to its linear shape), the molecule is ionic.

What is the difference between ions and polyatomic ions?

Polyatomic ions are formed when a GROUP of atoms gain or lose electrons, whereas, the ions we previously discussed form when a SINGLE ATOM loses or gains electrons.

Give the chemical formula for potassium sulfate.

Potassium: K^+ Sulfate: SO_4^(2-) Drop the signs and switch the numbers: K_2 SO_4

Give the number of protons, electrons, and neutrons in the following atoms: ^58 Ni

Protons: 28 Electrons: 28 Neutrons: 30

Give the number of protons, electrons, and neutrons in the following atoms: ^90 Zr

Protons: 40 Electrons: 40 Neutrons: 50

Give the number of protons, electrons, and neutrons in the following atoms: ^202 Hg

Protons: 80 Electrons: 80 Neutrons: 122

Give the number of protons, electrons, and neutrons in the following atoms: ^222 Rn

Protons: 86 Electrons: 86 Neutrons: 136

What was Rutherford's main contribution to the study of atomic structure?

Rutherford's main contribution to the study of atomic structure was disproving the plum pudding model of the atom and developing the planetary model of that atom as a revised and seemingly more accurate model of what an atom looks like.

Name the compound: SO_3.

S = Sulfur O = Oxygen 3 = Tri- Sulfur Trioxide

List the chemical formula (including charge) for following ion: sulfate.

SO_4^(2-)

Why does soap help to wash away stains that water cannot wash away by itself?

Soap helps to wash away stains that water cannot wash away by itself due to its molecular structure. Most stains are made of purely covalent (nonpolar) compounds. However, water is a polar covalent compound. Since polar covalent compounds can only dissolve other polar covalent compounds and ionic compounds, water cannot dissolve these stains. However, soap is composed of long molecules that are ionic on one end and purely covalent (nonpolar) at the other end. The ionic end allows the soap to mix with the water, and the purely covalent end dissolves the purely covalent stains, because purely (nonpolar) covalent compounds can only dissolve other nonpolar (purely) covalent compounds.

If a liquid goes through a phase change and all you know is that the molecules slowed down and moved closer together, what phase did the liquid turn into?

Solid

the amount of heat needed to increase the temperature by 1 degree Celsius of 1 gram of any given substance

Specific Heat

Define stoichiometry and explain why it is such a useful tool for chemists.

Stoichiometry - the process in a chemical reaction by which one substance amount is related to any other substance amount. Stoichiometry is such a useful tool for chemists, because it allows them to find the moles of all the substances in a chemical reaction--given the number of moles of a single substance in the reaction.

Does sublimation occur when something is heated or when something is cooled?

Sublimation occurs when something is heated, because a solid's molecules must gain energy (heat) in order to phase change from a solid to a gas, so the molecules can move faster in a larger area.

Name the following ion: SO_3 ^2-

Sulfite

Name the ionic compound: K_2SO_4.

The chemical formula of a compound is made by dropping the signs and switching the numbers of the individual elements' formulas. To find whether each element is positive or negative, we have to consult the periodic table. The two parts of this compound are K_2 and SO_4. SO_4 would have a charge of 2, and K_2 would have a charge of 1. Consulting the periodic table, K has a positive charge, and SO_4 has a negative charge. Thus, the two molecules would be K^+ and SO_4^(2-). In words, this would be Potassium Sulfate.

What is the difference between the continuous theory of matter and the discontinuous theory of matter?

The continuous theory of matter theory states that all forms of matter are each composed of long, unbroken blobs of more matter, whereas, the discontinuous theory of matter states that all forms of matter are made of tiny, individual particles--not long, unbroken blobs.

One electron is in a 2p orbital while another is in a 3s orbital. Which has the higher energy?

The electron in the 2p orbital

Which atom has the greatest desire for extra electrons: N, Sb, or As.

The electronegativity of atoms decreases from right to left and from top to bottom on the periodic table, in general. Thus, N has the greatest desire for extra electrons.

What is the energy of a light wave with a frequency of 3.5 x 1020 Hz?

The energy of a light wave with a frequency of 3.5 x 10^20 Hz is about 2.3 x 10^-13. E = h x f

What is the energy of a photon of green light with a frequency of 5.50 x 1014 Hz?

The energy of a photon of green light with a frequency of 5.5 x 10^14 Hz is 3.6 x 10^-19 J. E = h x f

A student measures the mass of an object as 2.32 grams and its volume as 34.56 mL. The student then calculates the density to be 0.067129629. There are two things wrong with the student's value for density. What are they?

The first thing that is wrong with the student's calculation for density is that the student did not label his final answer. There are no units with his numerical answer. The second thing that the student did wrong was his rounding (or lack thereof). Your measurements are limited to the least precise instrument. In this case, his final calculation of the density can only be to the nearest hundredth.

Two students measure the mass of a 502.1 gram object. The first student measures the mass to be 496.8123 grams. The second measures the mass to be 501 grams. Which student was more precise and which was more accurate?

The first was more precise, but the second was more accurate.

Which of the following atoms are isotopes? ^22Na, ^22Ne, ^23Na, ^22Mg, ^24Na

The following are isotopes ^22Na, ^23Na, and ^24Na

355mL = .355L 1.5(.355)=.5325 moles (.533mol Al(NO3)3)/1∙(1mol Al_2 (SO_4 )_3)/(2mol Al(NO3)3)=.2665mol Al_2 (SO_4 )_3 Aluminum sulfate = Al_2 (SO_4 )_3 = 2(27) + 3(32.1) + 12(16) = 342.3g .2665mol(342.3g) = 91.2229g About 91.2g of aluminum sulfate will be produced.

The following reaction is performed in a lab: 3Na2SO4 (aq) + 2Al(NO3)3 (aq) → Al2(SO4)3 (s) + 6NaNO3 (aq) If 355 mL of 1.50 M aluminum nitrate is added to an excess of sodium sulfate, how many grams of aluminum sulfate will be produced?

The fundamental particles that make an atom in terms of decreasing mass are as follows: neutron, proton, and electron.

Which atom gives up its electrons most readily: Al, B, In, or Ga.

The ionization energy of atoms decreases from right to left and from top to bottom on the periodic table, in general. Ionization energy is the amount of energy needed in order for an electron to be taken away from an atom. Thus, the higher on the periodic table an element is, the tighter it holds onto its electrons. Since Al, B, In, and Ga are all in the same column, the lowest element will give up its electrons the most readily. In is the lowest element, so it gives up its electrons the most readily.

Order the following atoms in terms of increasing ionization potential: Sr, Sb, I.

The ionization energy of atoms decreases from right to left and from top to bottom on the periodic table, in general. Thus, from the lowest ionization energy to the highest would be as follows: Sr, Sb, and I.

The specific heat of iron is roughly three times that of gold. Equal masses of gold and iron start out at room temperature. Heat is added to each mass at the same rate for the same amount of time. When it is all over, the gold's temperature increased by 600 degrees C. What was the temperature increase of the iron?

The iron would have to be 200⁰C (600 degrees C /3 = 200⁰C).

The chemistry of life is based on carbon. This means that all of the molecules which govern life- giving chemistry have carbon atoms as their principal component. Chemists have often speculated that there could be a life form with a chemistry based on silicon. Why?

There could be a life form with chemistry based on silicon, because elements in the same column on the periodic table have similar chemistry. Silicon and carbon are the only nonmetals in column 4A, so they have very similar chemistry. Thus, one of the similarities between the chemistries of the elements could support life.

Examine the heating curve for the following unknown substance. Disregard points D-F. At what temperature does this substance boil? How do you know?

This substance appears to boil at point B. I know this, because the substance stops heating up at point B and remains the same temperature until the end of the graph. When a substance boils, it does not increase in heat.

V_1=V_2 T_1=T_2 n_1=1.7 moles of N_2 n_2=1.7 moles of SO_3 n_1=n_2 P_1 V=nRT AND P_2 V=nRT P_1=P_2 The pressures of the two containers are equal.

Two steel containers of equal volume contain two different gases at the same temperature. The first container holds 1.7 moles of N2 gas and the second contains 1.7 moles of S03 gas. Compare the pressures of the two containers.

Gases behave ideally when their pressure is close to or less than 1.000 atm and their temperature is close to or above 273K.

Under what conditions do gases behave ideally?

2C6H6 (l) + 〖15O〗_2 (g) 12CO_(2 ) (g)+〖6H〗_2 O (g) C6H6 = 6(12) + 6(1.01) = 78.06 g/mol 550g is about 7.05 moles ∆Ho = -6278 7.05(-6278) = -44259.9 kJ -44259.9 kJ/ 2 moles = -22129.95 -22129.95 kJ of energy will be released when 550 g of benzene are burned.

Using ∆H = -6278 kJ (the answer to question P2 from the previous lesson), calculate the number of kJ of energy released when 550.0 grams of benzene are burned in excess oxygen.

Give the abbreviated electron configuration of: oxygen

[He]2s^2 2p^4

Give the abbreviated electron configurations of the following atoms: In

[Kr]5s^2 4d^10 5p^1

Give the abbreviated electron configurations of the following atoms: Sn

[Kr]5s^2 4d^10 5p^2

Give the abbreviated electron configuration of: sodium

[Ne]3s^1

Give the abbreviated electron configuration of: aluminum

[Ne]3s^2 3p^1

How many electrons are in the valence shell of the atoms: aluminum

[Ne]3s^2 3p^1 2 + 1 = 3 electrons in the valence shell of an aluminum atom.

Give the abbreviated electron configuration of: barium

[Xe]6s^2

What is the symbol of the atom made up of 39 protons, 45 neutrons, and 39 electrons?

^84Y

Write the equation for the alpha decay of radon-198.

_86^198Rn -> _84^194Po

Write the equation for the beta decay of uranium-237.

_92^237U -> _93^237Np

Acid Base

_______ + _______ --> Salt + Water

Titration

____________ determines the concentration of an unknown base or acid.

The element with the __________ electronegativity will have the strongest _____.

highest pull

"kJ" stands for ______________

kiloJoules

Classify the following as having either potential or kinetic energy, or both: A candle flame.

kinetic energy

Classify the following as having either potential or kinetic energy, or both: A flash of lightning.

kinetic energy

metals ______ valence electrons, and nonmetals ______ valence electrons

lose gain

acid base

pH < 7 = ______ pH > 7 = _______

Classify the following as having either potential or kinetic energy, or both: A tornado.

potential and kinetic energy

Classify the following as having either potential or kinetic energy, or both: A lump of coal.

potential energy

P = F/A is the formula for what?

pressure

A 354.1 g sample of copper at 100.0 degrees C is dropped into a 5.5 g calorimeter made of an unknown substance. If the calorimeter has 160.0 grams of water in it and the temperature changed from 24.2 degrees C to 25.3 degrees C, what is the specific heat of the calorimeter (in J/g°C)?

q=mc(DeltaT) q_water=(16.0 g)(4.184 J/g*degrees C)(1.1 degrees C)=740.0 J q_metal=(354.1 g)(.3851 J/g*degrees C)(-74.7 degrees C)=-10200 J -q_metal=q_water + q_calorimeter 10200 J=740 J + q_calorimeter q_calorimeter=10200 J - 740 J=94600 J c=(9460)/((5.5 g)(1.1 degrees C)) =1.6 x 10^(3) (J/g*degrees C)

Calculate how many Calories are burned when a 355 g glass of water at 0.0 degrees C is warmed up to body temperature (37.0 degrees C).

q=m∙c((cal.)/(g ∙ degrees C))∙∆T ∆T=T_Final-T_Initial q=355 g ∙1.000∙(37.0℃-0.0℃) q=13135 cal. 1 Cal. = 1,000 cal. (13135 cal.)/1000=13 Cal. 13 Calories are burned when a 355 g glass of water at 0.0⁰C is warmed up to body temperature.

A 425 g piece of copper at room temperature (25 degrees C) loses 654.7 Joules of heat. What will its new temperature be?

q=m∙c(J/(g ∙ degrees C))∙∆T ∆T=T_Final-T_Initial -654.7 J=425∙ .3851∙(degrees 0 C-25 degrees C) -654.7 J=163.7∙(degrees C-25 degrees C) -654.7J/163.7=℃-25 degrees C -4.0 +25= ℃ = 21⁰C The copper's new temperature will be 21⁰C.

How many Joules does it take to heat up 12.1 kg of glass from 15 degrees C to 40 degrees C?

q=m∙c∙∆T ∆T=T_Final-T_Initial C_glass=.8372 12.1 kg ∙1000=12100 g q=12100g∙ .8372 (J/(g ∙ degrees C))∙(40 degrees C-15 degrees C) q=253253 J It takes 253,253 J to heat up 12.1 kg of glass from 15⁰C to 40⁰C.

CHEM350 FINAL

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