HChem Final S1

In one sentence, describe why ionization energy increases from bottom to top.

As the atomic radius increases UP a group, the electrons in the valence shell are more attracted to the nucleus' positive protons and are, therefore, harder to remove from the atom.

In one sentence, describe why electronegativity increases from left to right.

As you go from left to right on the periodic table, the atoms get smaller. This is due to a greater attraction between the protons in the nucleus and the electrons. Electronegativity is the ability to attract new electrons, since the atom is smaller its protons are able to attract new electrons more easily.

In one sentence, describe why ionization energy increases from left to right.

As you go from left to right on the periodic table, the atoms get smaller. This is due to a greater attraction between the protons in the nucleus and the electrons. Ionization energy is the energy required to take away an electron, because the atoms are getting smaller and there is a greater attraction between the protons and the electrons it is harder to remove the electrons making the ionization energy greater.

What phase change has occurred if is the state of the chemical illustrated above goes from a pressure of 30 atm and temperature of -10 °C to 30 atm and 25°C?

At 30 atm and -10 the substance is in a solid state... At 30 atm and 25 the substance is in a liquid state Melting occurred (look at powerpoint)

In one sentence, describe why atomic radius increases from top to bottom.

Atomic Radius increases as you move down the periodic table because of the addition of an energy level

In one sentence, describe why atomic radius decreases from left to right.

Atomic radius decrease as we go across the periodic table because of an increase in nuclear charge. As you move across the periodic table there is an addition of one proton and one electron per element, the attraction between the protons and electrons increases, thus pulling the electrons in tighter.

In one sentence, describe why electronegativity increases from bottom to top.

Atoms increase is size as you go from top to bottom, so the largest atoms are at the bottom. Because of their size it is harder for them to attract new electrons, mainly because their nucleus and protons are so far away from the outer shell of electrons. As you go from bottom to top, the atoms get smaller and can attract new electrons more easily.

Titanium has five common isotopes: 46Ti (8.0%), 47Ti (7.8%), 48Ti (73.4%), 49Ti (5.5%), 50Ti (5.3%). What is the average atomic mass of titanium?

Average Atomic Mass=(46amu x 0.08)+(47amu X 0.078)+(48amu X 0.734)+(49amu X 0.055)+(50amu X 0.053) Average Atomic Mass= 47.923 amu (Average Atomic Mass=[Mass # x %in Nature(Isotope 1) + Mass # x %in Nature(next isotope)] (keep going until done)

The correct lewis structure for ammonia (NH3) has... a. 3 single bonds and no lone pairs b. 3 single bonds and 1 lone pair c. 2 single bonds and 2 lone pairs d. 2 single bonds and 1 double bond

B

What is a chemical preperty of copper? a. has a boiling point of 2567 °C b. reacts in air to form a green layer c. has a chemical symbol Cu d. is a solid at room temperature

B

Water could be made to boil at 85 °C instead of 100° C by ______. a. adding a lot of energy to the water B. decreasing the external pressure C. increasing the external pressure d. taking the sample to a higher altitude

B (possibly d) Decreasing the external pressure (which will happen in higher altitudes)

222/86Rn undergoes two alpha decays and then 1 beta decay. What isotope is formed? a. Uranium-234 c. Bismuth-214 b. Polonium-218 d. Bismuth-218

C

Why is a SOLID harder to compress than a gas or liquid? a. Its volume increases more under pressure than an equal volume of liquid does. b. Its volume increases more under pressure than an equal volume of gas does. c. The space between solid particles is much less than the space between liquid or gas particles. d. The space between solid particles is much greater than the space between liquid or gas particles.

C

In figure 1, which covalent molecule has the strongest bond? a. A (single) b. B (double) c. C (triple) d. They are all equally strong

C, The greater the number of bonds between two atoms, the stronger the bond between those atoms.

In one sentence, define electronegativity?

Electronegativity is an atom's ability to attract a bonding pair of electrons.

INTERmolecular forces vs. INTRAmolecular forces

INTERmolecular forces are the forces between molecules and INTRAmolecular forces are the forces within one molecule

In one sentence, define ionization energy?

Ionization energy is the amount of energy required to remove the an outermost electron from an atom.

Which of these elements will have the larger atomic radius? -Li or Be -As or Ca -P or Sb -Fr or F -Br or Bi

Li Ca Sb Fr Bi

Explain why/how we see color

Light can be emitted or reflected. When we see color, like a red shirt it is being reflected off of another object. If you are standing outside, the light is being emitted from the sun, and the shirt is absorbing all of the energy from that light except the energy we think of as red. We define the color red by a specific wavelength, which can be converted to energy.

Lithium has two naturally occurring isotopes: lithium-6 and lithium-7. If the average atomic mass of lithium is 6.941 amu, which isotope is the most abundant? How do you know?

Lithium - 7 would most likely be the most abundant because the average atomic mass takes into account the abundance of each isotope. Since the average is closer to Li -7, it implies that this isotope has a bigger impact to the average because it's more abundant.

Which IMFs is(are) responsible for holding SEPARATE Cl2 molecules together in the liquid state?

London Dispersion Forces These forces are also referred to as induced dipoles. They exist between all neutral molecules. Cl2 molecules do not have a dipole because the two atoms have equal electronegativities and do not have dipole-dipole forces as a result. They do not have a N-H, O-H or F-H bond and hence do not have hydrogen bonding.

Composition of Several Elements, Fill in blanks. Pb ________ _______ ________ b. _______ ________ 8 ________ c. _______ ________ _______ 30 (Element, atomic number, number of protons, number of electrons)

Pb: 82 82 82 O (Oxygen): 8 8 8 Zn(Zinc): 30 30 30

Draw electron configurations for the following elements: -Oxygen- O -Argon- Ar -Zinc- Zn -Tellurium-Te

Picture is an example of electron configuration

Draw orbital diagrams for the following elements: -Hydrogen- H -Oxygen- O -Argon- Ar

Picture is an example of orbital diagram

Write the shorthand electron configurations for the following elements: -Bromine- Br -Strontium- Sr -Titanium- Ti

Picture is an example of short hand

Define the following observations as: a. qualitative b. quantitative -The freshmen class is very large this year.

Qualitative

Define the following observations as: a. qualitative b. quantitative -The horn is very loud and shrill.

Qualitative

Define the following observations as: a. qualitative b. quantitative -The child is 42 inches tall.

Quantitative

Define the following observations as: a. qualitative b. quantitative -The jet plane engine is 140 decibels loud.

Quantitative

Measurements made during an experiment are what kind of observations?

Quantitative For quantitative, think numbers (data)

Describe what each part of the electron configuration represents: 5d4

The 5 determines the orbital pattern, the d determines the shape of the orbital and the 4 is how many electrons are in the orbital

What causes the four spectral lines that are produced when hydrogen gas is excited

The release of photons from the atom as the electrons leave the excited state

In one sentence, define ionic radius?

The radius of the ion. It will differ from the parent (or neutral atom) depending on whether it was metal or non-metal. Metals lose electrons and the resulting ion size is smaller. "Peeled" away the outermost energy level and therefore smaller Non metals gain electrons and the resulting ion size is larger. More electron electron repulsion, expands the radius

How did Thomson's plum pudding model increase our knowledge of the structure of the atom?

Thomson's experiment with the Cathode Ray Tube, provided evidence for a negatively charged subatomic particle. This finding, along with the knowledge that matter is typically neutral, provided the basis for the Plum Pudding model. This was the first model that suggested atoms were made of divisible, charged particles and established the presence of electrons.

The theoretical yield in a particular chemical reaction is 0.1062 g. The actual yield obtained by a chemist in an experiment is 0.0098g. Calculate the percent error for this experiment.

((Experimental - theoretical)/ theoretical )x 100% ((0.0098g - 0.1062g) / 0.1062g) x 100%= 90.77% with significant figures: 91% (error=experimental-accepted) (% error=((|error|)/(accepted))x100%)

Draw an orbital diagram and full electron configuration for the following ions: -Ca2+ -F1-

(do on paper) (examples in previous notecards)

A year is 365.25 days, and a decade has exactly 10 years in it. How many days are in 2 decades?

2 Decades x 10 years/1 decade x 365.25 days/ 1 year = 7305 days

Determine the number of atoms in 2.50 mol Zn

2.5 mol Zn x 6.02x10^23 atoms Zn/1 mol Zn= 1.5x10^24 atoms Zn

Determine the number of moles of chloride ions in 2.50 mol ZnCl2.

2.50 mol ZnCl2 x 2 mol Cl-/1 mol ZnCl2=5 mol Cl-

In your own words, define accuracy and precision:

accuracy: Is being close to the actual and not having your data being far off from the correct answer precision: Is when your data is all close together but it can not be accurate

Convert to sci. not. or to standard notation. 0.00530

5.30 x 10^-3

Convert to sci. not. or to standard notation. 56 760 000 000

5.676 x 10^10

Explain how and why a photon is emitted from an atom

A photon is emitted from an atom when the atom has become excited(by heat or electricity), the electron moves to a higher energy level. When it returns back to ground state, the energy is released in the form of a photon.

Given the following elements, will the radius of the ion of that element be larger or smaller than that of the neutral element? -Li -Mg -F -P -Ga -H

-Smaller (loses valence shell) -Smaller (loses valence shell) -Larger (more electrons held in less by the protons & more electrons repelling each other) -Larger (more electrons held in less by the protons & more electrons repelling each other) -Smaller (loses valence shell) -Smaller (loses valence shell)

Convert to sci. not. or to standard notation. 1.53 x 10-4

0.000153

Calculate the number of molecules in 11.5 mol H2O.

11.5 mol H2O x 6.02x10^23 molecules H20/1 mol H20=6.92x10^24 molecules H2O

Given 3.25 mol AgNO3, determine the number of formula units.

3.25 mol AgNO3 x 6.02x10^23 F.Un. AgNO3/1 mol AgNO3=1.96x10^24 F.Un. AgNO3

How many moles are in 3.40 X 1096 molecules of carbon monoxide (CO)?

3.40x10^96 molecules CO x 1 mol CO/6.02x10^23 molecules CO=5.65x10^72 mol CO

How many molecules are in 35.4 mol CO2?

35.4 mol CO2 x 6.02x10^23 molecules CO2/1 mol CO2=2.13 molecules CO2

The following are placed in a beaker weighing 39.457 g: 2.689 g of NaCl, 1.26 g of sand and 500.0g water. What is the final mass of the beaker?

39.457g + 2.689g + 1.26g + 500.0g = 543.406g With significant figures applied this value becomes: 543.4g (The least precise measurement has 1 decimal place. Use the least precise measurement when applying sig figs for addition and subtraction.)

Express each of the following in scientific notation. 8960 ___________________ 0.00023 ________________ 86,000 _________________ 8.5 _____________________

8.96x10^3 2.3x10^-4 8.6x10^4 8.5x10^0

Convert to sci. not. or to standard notation. 898 000.

8.98000 x 10^5

An isotope undergoes beta decay to produce 56/26Fe What isotope did this decay begin with? a. Manganese-56 c. Cobalt-56 b. Manganese-57 d. Cobalt-57

A

The combining of two nuclei to form a larger one is known as a. nuclear fusion b. nuclear fission

A

What Molecular shape does the compound formaldehyde (H2CO) have? a. trigonal planar b. trigonal pyramidal c. tetrahedral d. bent

A

Which of the following combinations of elements will not typically result in ionic bonding? (ionic is between a metal and a nonmetal) (covalent is between two nonmetals) a. O and S b. O and Ca c. O and Ba d. O and Li

A

Which of the structures below is a nonpolar molecule? a. methane b. methanol c. ammonia d. b and c non polar

A

Which type of radiation is the least harmful? a. alpha particles c. gamma rays b. beta particles d. they all have the same risk

A, Alpha particles have the weakest penetration power and in comparison to the others and is the least harmful.

Which is true of the BOND LENGTH of the molecules in figure 1 a. the bonds in A are longer than the bonds in B or C b. the bonds in C are the same length as the bonds in B c. the bonds in B are longer than the bonds in A or C d. the relative bond length of these compounds cannot be determine

A, The more bonds there for between two atoms, the more tightly bonded they are. This results in a shorter bond length for triple bonds compared to double bonds. Double bonds are also shorter than single bonds for this reason.

Name the following compounds: a.KOH b.Mg3(PO4)2 c.NaNO3 d.Cs2CrO4 e.NH4OH

A.potassium hydroxide B.magnesium phosphate C.sodium nitrate D.cesium chromate E.ammonium hydroxide

Which of the molecules shown to above evaporates faster? a. Methane because it stronger IMFs. b. Methane because it weaker IMFs. c. Ammonia because it weaker IMFs. d. They would evaporate at the same rate

B, Methane is nonpolar and would, therefore, only have London Dispersion forces (the weakest type of IMFs). Ammonia is polar and would have dipole-dipole forces. Ammonia also can have hydrogen bonding. These are the two strongest types of IMFs. Molecules with strong IMFs will have a low vapor pressure and therefore a slower evaporation rate. Therefore, methane's weak IMFs would give it a higher vapor pressure, allowing it to evaporate faster.

Which of the molecules in the figure to the right has a bent shape? a. hydrogen b. hydrogen sulfide c. ammonia d. methane e. methyl alcohol

B, Notice that there are no lone pairs shown on the molecules. When the proper lone pairs are added to the molecules, hydrogen sulfide has two lone pairs. This results in a bent structure with a bond angle of 109͒

Describe the difference between bond polarity and molecular polarity.

Bond polarity occurs when the central atom has an uneven pull on it and the net electronegativity is 0.3+ molecular polarity is interactions through dipole-dipole intermolecular forces and hydrogen bonds=[7

What is the state of the chemical represented in the phase diagram at 30 atm and 50°C? a. solid b. liquid c. both solid and liquid d. both liquid and gas

D, check powepoint

A cup of gold colored metal beads was measured to have a mass 425 grams. By water displacement, the volume of the beads was calculated to be 48.0 cm3. Given the following densities, identify the metal. Gold: 19.3 g/mL Copper: 8.86 g/mL Bronze: 9.87 g/mL

D=M/V D= 425g/48cm3 D= 8.86 g/cm3 (1 cm3= 1mL) Copper!

What is the density of a piece of wood that has a mass of 25.0 grams and a volume of 29.4 cm3?

Density= Mass/Volume Density= 25g/29.4cm3 Density= 0.85 g/cm3

A piece of wood that measures 3.0 cm by 6.0 cm by 4.0 cm has a mass of 80.0 grams. What is the density of the wood? (volume = L x W x H)

Density= mass/volume Volume= Length X Width X Height Volume= 3.0cm X 6.0cm X 4.0cm Volume= 72 cm3 Density= 80g/72cm3 Density= 1.11 g/cm3

Which of these elements will be more electronegative? -B or F -Si or Ge -Cl or S -As or F -Rb or Ga

F Si Cl F Ga

If the beaker containing a sample of alcohol weighs 49.8767 g and the empty beaker weighs 49.214 g, what is the weight of the alcohol?

Mass of alcohol= 49.8767g - 49.214g Mass of alcohol= 0.6627g (W/ sig figs: 0.663g)

In metallic bonding, what does it mean to say that the Atoms create a "sea of electrons"?

Metallic atoms hold on to their valence electrons very weakly. When they form metallic bonds, these weakly attached electrons are released and are free to move throughout the compound. The atoms remain dispersed amongst the free flowing electrons as cations.

Describe the Gold Foil experiment and indicate what information about the atom was gained from this experiment.

Most alpha particles passed through Conclusion made from this observation is ATOM MOSTLY EMPTY SPACE Some alpha particles deflected and few bounced back. Conclusion made from this observation is ATOM has a small dense core (NUCLEUS)

A runner runs the last 45m of a race in 6s. Give the speed of the runner in m/s.

Speed= distance / time Speed = 45m/6s Speed = 7.5 m/s (w/ sig figs: 8 m/s)

If an electron jumps from energy levels 6 to 2, and another electron jumps from 6 to 4, which has more energy?

The bigger the electron transition, the more energy involved (shorter wavelength) The transition from 6 to 2 would release a photon with more energy.

Describe resonance in your own words. Then show the resonance structures for the NO31- ion? Also for benzene.

The bonding of one molecule can be represented by many different lewis structures

Which of the sublevel is shaped like a four petal flower?

The sublevel d

Use the diagram below to: a. Label the wavelength. b. On top, or next to the diagram, draw a wave with higher energy. c. Circle/indicate the wave with the higher frequency.

a. 0.25 micrometers b. 0.10 micrometers c. higher frequency equals the wave with the length of 0.10 micrometers

Determine the molar mass: a. NaOH b. Sr(NO3)2

a. 23+16+1.008=40g b. 88+28+96=212g

Solve the problems and express the answer with the correct number of significant figures. A. 5.30 x 4.356 b. 8.5 + 5.356

a. 23.1 b. 14

Determine the mass in grams of each of a. 3.57 mol Al b.125 g Zn

a. 3.57 mol Al x 27g Al/1 mol Al=96.4g b. already in grams

73. Round the number 31.257592 to the requested number of significant digits. a. 5 sig figs b. 3 sig figs c. 1 sig fig

a. 31.258 b. 31.3 c. 30

Determine the formula for the following compounds: a. Potassium and iodide b. Magnesium and chloride c. Aluminum and bromide d. Cesium and nitride e. Barium and sulfide

a. KI b. MgCl2 c. AlBr3 d. Cs3N e. BaS

PICTURE

a. Measurement of A: 2.40 cm b. Measurement of B: 2.65 cm (2.64cm or 2.66cm would also be acceptable) ** Don't forget the estimated value**

What is the mass in grams of each of the following? a. 3.40 x 10^22 atoms He b. 1.50 x 10^15 atoms N

a. 4.40x10^22 atoms He x 1 mol He/6.02x10^23 atoms He x 4g He/1 mol He=2.92 g He b. 1.50x10^15 atoms N x 1 mol N/6.02x10^23 atoms N x 14 g N/1 mol N=3.50x10^-8 g N

How many atoms are in each of the following samples? a. 55.2 g Li b. 0.230 g Pb

a. 55.2 g Li x 1 mol Li/7 g Li x 6.02x10^23 atoms Li /1 mol Li=4.75x10^24 atoms Li b. 0.230 g Pb x 1 mol Pb/207 g Pb x 6.02x10^23 atoms Pb/1 mol Pb=6.689 atoms Pb

What families do the following elements fall into? a. H b. Li c. Co d. He e. Cl

a. Alkali metals (although it is not a metal) b. Alkali metals (although it is not a metal) c. Transition metal d. Noble Gas e. Halogen

Which of these elements will have the higher ionization energy? a. Li or Be b. Li or Na c. N or O d. Ne or Kr e. F or S

a. Be b. Li c. O d. Ne e. F

Name the following binary covalent compounds: a. CS2 b. NO c. N2O2 d. SF2 e. IF7 f. P4S10

a. Carbon disulfide b. Nitrogen monoxide c. dinitrogen dioxide d. Sulfur difluoride e. Iodine heptafluoride f. Tetraphosphorus decasulfide

Classify the following properties of water as physical or chemical: a. Reacts with certain metals and metal oxides to form bases. b. Melting point: 0°C c. Forms rust when in contact with iron d. It expands greatly as it freezes e. Density: 1.0 g / cm3 f. Reacts with certain organic compounds to form alcohols g. Colorless h. Completely pure water is a poor conductor of electricity

a. Chem b. Phys c. Chem d. Phys e. Phys f. Chem g. Phys h. Phys

Determine the correct formula: a. Sodium and nitrate b. Calcium and chlorate c. Aluminum and carbonate d. Potassium and chromate e. Magnesium and carbonate

a. NaNO3 b. Ca(ClO3)2 c. Al2(CO3)3 d. K2CrO4 e. MgCO3

Name the following compounds a. NaCl b. K2O c. MgO d. AlF3 e. CuCl2 f. ZnF2 g. Hg2O h. FeCl2

a. Sodium chloride b. Potassium oxide c. Magnesium oxide d. Aluminum fluoride e. Copper (II) chloride f. Zinc fluoride g. Mercury (I) oxide h. Iron (II) chloride

Trial Density Deviation (g/mL) (g/mL) 1 10.5 2 11.9 3 13.0 4 11.5 5 9.3 6 12.8 7 12.5 mean=11.6 Given the data in the chart, complete the following tasks: SHOW YOUR WORK, Accepted Density Value: 12.1 g/mL a. Calculate Error: b. Calculate Percent Error: c. Find the Deviation for each trial, fill in chart. d. Calculate Average Deviation: e. Calculate Percent Deviation: f. Was the overall experiment accurate? Explain. g. Was the overall experiment precise? Explain. h. Can we be confident in this group's data? Explain.

a. error=experimental-accepted 1. -1.6 2. -0.2 3. 0.9 4. -0.6 5. -2.8 6. 0.7 7. 0.4 b. %error=((|error|)/(accepted))x100% 1. 0.13% 2. 0.017% 3. 1.1% 4. 0.95% 5. 0.77% 6. 1.1% 7. 1.03% c. Deviation=trial-mean 1. -1.1 2. 0.3 3. 1.4 4. -0.1 5. -2.3 6. 1.2 7. 0.9 d. Average deviation=mean of deviations/# of trials average deviation=1.04 e. % deviation=(av. deviation/mean)x100% %deviation=0.09% f. It wasn't really quite accurate because most the time they were around 0.5+ off g. It wasn't too precise again their data was around 0.5+ off from each other h. Not really

72. Check the following equalities for errors. If answer correct, write correct. If answer is incorrect, rewrite in the scientific notation to be correct. ______________ ____ 45,630,000= 4.563 x10^7 ___________________0.000253 = 2.53 x 10^-3 ___________________680,500,000 = 68.05 x 10^8

correct incorrect, 2.53x10^-4 correct

A beam of light has 4.25 × 10^-19 J of energy, what is its wavelength in nanometers?

e=-(2.18x10^-18j)/n^2 (energy level stuff) c= 3.00 × 10^8 m/s h = 6.63 × 10^-34 J·s E = h × v 1 m = 1 × 10^9 nm c = λ × v λ=wavelength v=frequency e=energy v=4.25x10^-19j/6.63x10^-34j.s=6.41x10^14/s λ=3.00x10^8m/s/6.41x10^14/s=4.68x10^-7m

Alpha decay

is a radioactive process in which a particle with two neutrons and two protons is ejected from the nucleus of a radioactive atom. The particle is identical to the nucleus of a helium atom.

Describe the progression of the atom throughout history. Include: Dalton, Thomson, Rutherford, Bohr and the Quantum Model

look at powerpoint

Beta decay

occurs when, in a nucleus with too many protons or too many neutrons, one of the protons or neutrons is transformed into the other

Draw the correct lewis structure for Carbon Dioxide, Label the partial charges and tell if the MOLECULE is polar or non-polar

partial neg-->partial pos-->partial neg Carbon dioxide is a NON POLAR molecule with polar bonds that cancel out.

Define Isotope.

two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass (mass number) but not in chemical properties

Describe isomers in your own words. Then show all isomers for C3H6Cl2

you can draw more than one structural formula for one kind of molecule but it makes the molecule different