Chemistry Final 2021

Which of the following is a molecular formula?

NO2

What is the charge of the iron ion in FeO?

+2

Which of the following does not correctly show an ion-dipole interaction?

+h-f-->...S2-

How many lone pairs does the carbon tetrachloride (ℂCl4) molecule have?

0

Some rocket engines use a mixture of hydrazine, N2H4, and hydrogen peroxide, H2O2, as the propellant. The reaction equation is N2H4(l)+2 H2O2(l)→N2(g)+4 H2O(g). When 0.750 mol N2H4 is mixed with 0.500 mol H2O2, how much N2, in moles, is formed? Be sure to use the limiting reagent

0.250 moles

A balloon is filled with 2 liters of air at sea level, then a scuba diver carries it under the ocean. If the scuba diver stops when the pressure on the ballon is 3 atmospheres, what is the new volume of the balloon? Round to the nearest hundredth.

0.67 L

How many atoms are bonded to the central atom in a fluorine (F2) molecule?

1

How many moles of carbon dioxide are produced in the reaction between hydrochloric acid and calcium carbonate when 2 moles of HCl are used to start with?

1

A sample of gas at 0.5 atmospheres is compressed until it is under 2.5 atmospheres. The temperature is measured as 900 K after it is compressed. What was the temperature of the gas before its pressure changed? Round to the nearest hundredth.

180K

How many moles are present in 60 grams of hydrochloric acid, HCl? checkCorrect1.65

1.65 moles

Radon-222 has a half-life of 2.8 days. How many half-lives will pass after 28 days?

10

what is the mass of an atom with 44 protons, 42 electrons, and 57 neutrons

101

the most common form of an argon atom has how many neutrons

22; neutrons= most common mass - atomic number

the atomic number of an atom with 1 4 neutrons and a mass of 27 is --

13

The combustion of glucose is represented by the following balanced equation: C6H12O6+6 O2→6 H2O+6 CO2.The reaction uses 1 gram of both C6H12O6 and O2. What is the percent yield if 0.45 g of H2O is produced?

80%

What is the mole ratio of calcium carbonate to carbon dioxide in the reaction between hydrochloric acid and calcium carbonate?2HCl+CaCO3→CaCl2+CO2+H2O

1:1

what is the electron configuration for zirconium

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d2

A diatomic molecule has _____ atom(s)

2

how many electrons does calcium have in its outermost shell

2

You have 500 mL of 5 M HCl already made. You need to dilute the solution to 1 M HCl. How much water will you need to add?

2.0 L

A balloon is filled with 2 liters of air at sea level. If the balloon is taken up a mountain so that the new air pressure is approximately 0.94 atmospheres, what will the new volume of the balloon be? Round to the nearest hundredth.

2.13 l

sample of gas at 3 atmospheres and 115∘ C is cooled to 15∘ C. What pressure will the gas be under after it is cooled? Round to the nearest hundredth.

2.23 atm

A 8 L sample of gas at 250 K is cooled to 75 K. What is the volume of the gas after it is cooled?

2.4 L

How many neutrons does the most common form of barium have?

81

Which reaction will not be affected by changing the volume of the container in which it takes place?

2S2O3(ag)+12(aq)<--> 24O6(aq) + 2I(aq)

How many atoms of sulfur are there in Al2(SO4)3?

3

How many moles of propane are needed to completely react with 15 moles of O2?

3

how many electrons does boron have in it s outer most shell

3

Rounding to the appropriate number of significant digits, calculate 5.37801-2.005

3.373

Rounding to the appropriate number of significant digits, calculate 10.23 x 3.0

31

Laughing gas (nitrous oxide, N2O) is sometimes used as an anesthetic in dentistry. It is produced when ammonia nitrate is decomposed according to the following reaction.NH4NO3(s)→N2O(g)+2H2O(l)How many grams of NH4NO3 are required to produce 33.0 g N2O? Show your work.

33.0g N2O x 1 mole N2O / 44g N2O x 1 mole NH4NO3/ 1 mole N2O x 80g NH4NO3/ 1 mole NH4NO3 = 60g NH4NO3 Molar Mass of N2O: N= 14(2) = 28g O= 16(1) = 16g 28 + 16 = 44g Molar Mass of NH4NO3: N= 14 (1) = 14 H= 1(4) = 4 N = 14 (1) = 14 O= 16(3) = 48 14 + 4 + 14 + 48 = 80

Determine the molar mass of lactose, C12H22O11.

342 g/mol

How many individual orbitals does carbon use for all of its electrons? Remember, there are two electrons in each filled orbital.

4

How many significant numbers are in 0.0003090

4

how many individual orbital does carbon use for all of its electron. remember, there are 2 electrons in each filled orbital

4

If a 160 mL sample of gas has a temperature of 200 K, what will the new temperature be if the gas has a new volume of 320 mL? 575

400K

balloon can hold 10 liters of a gas. If you blow up this balloon with 2 moles of oxygen gas at a pressure of 0.76 atmospheres, what is the temperature of the balloon? Pay attention to the unit of pressure used.

46.3 K

what is the correct number of protons, neutrons, and electrons for a neutral atom of silver

47, 61, 47

How many moles are represented by 3.01⋅1024 oxygen atoms

5 moles

How many moles of NaF are produced in the reaction between sodium bromide and calcium fluoride when 550 grams of sodium bromide are used?

5.35 mol NaF

A sample of gas is heated from 25∘ C to 50∘ C. If the original volume is 500 mL, what is the final volume? Round to the nearest milliliter

542 mL

What is the mole ratio of oxygen to carbon dioxide in the combustion reaction for propane?C3H8+5O2→3CO2+4H2O

5:3

How many moles of chlorine are present in 3 moles of MgCl2? 3

6

If you have 3 moles of a gas at a pressure of 2.5 atmospheres and a volume of 8 liters, what is the temperature? Pay attention to the unit of pressure used.

81.27 K

Convert 850,000,000 milliliters to kiloliters. Use the conversion factors 1 liter = 1,000 milliliters and 1 kiloliter = 1,000 liters. 8.50⋅1014

850 kiloliters

a neutral atom of astatine would have how many electrons

85; neutrons = protons

How many significant digits are there in 5.00920

6; numbers that are significant: nonzero numbers, zeros in the middle of non zero numbers, trailing zeros after a decimal point

How much energy is produced when CO2 is formed if each C-O bond releases 350 kJ?

700 kJ

A sample of gas at 15 atmospheres and 445 K is cooled to 250 K. What pressure will the gas be under after it is cooled? Round to the nearest hundredth.

8.43 atm

What is the main difference between a Brønsted-Lowry acid and a Lewis acid?

A Brønsted-Lowry acid is a compound that gives up a proton, while a Lewis acid accepts a lone pair.

Describe how an electric field affects molecules with polar bonds and molecules with non-polar bonds.Use examples to support your answer.

A molecule with a non-polar bond will not be affected when placed into an electric field; however, a molecule with a polar bond will be affected. A polar molecule has a partially negative end and a partially positive end. An atom that is more electronegative will be the partially negative end. A dipole is a molecule that has a positive end and a negative end; therefore, a polar molecule will be a dipole. The dipole, or the polar molecule, will place itself in the middle of the electric field, because opposites attract, the partially positive end will point towards the negative side of the electric field and the partially negative end will point towards the positive side of the electric field.

Determine the acid type for HBr.

Ahrrenius

What is the highest number of valence electrons that can be shown in an electron dot structure?

An electron dot structure can show a maximum of eight valence electrons.

Which indicator could be used to show that a nuclear reaction occurred?

An element changes identity.

Who is credited with the work that led to the conservation of mass?

Antoine Lavoisier

explain the trend for atomic size

Atoms on the periodic table follow periodic trends that determine their size, radius, and electro negativity. Trends for atomic size go as follows, atomic radius decreases from left to right, electronegativity increases from left to right, and atom size increases as you move down a group. Atomic radius decreases from left to right since elements with more protons have a smaller radius. As a result of atomic radius decreasing from left to right, electronegativity increases. The size of the atom increases as you move down a group since the number of protons increase, therefore the number of neutrons increase as well.

what element in the second period has the largest atomic radius

Be; atomic radius decreases from left to right

Who hypothesized that lightening and electricity were the same

Ben Franklin

Determine the molar mass of acetic acid, CH3COOH. 38 g/mol

C=2 atoms⋅12 g/mol=24 g/mol H=4 atoms⋅1 g/mol=4 g/mol O=2 atoms⋅16 g/mol=32 g/mol Add the mass of each element in the compound. 24+4+32=60 g/mol There are 60 grams per mole of acetic acid.

Which equation represents a balanced chemical equation?

CF4+2Br-->CBr4+2F2

Which of the following molecules has a dipole moment?

CHCl3

Which of the following compounds is likely to be a base?

Ca(OH)2

Explain what dimensional analysis is, and give at least three examples of what it can be used for. Use details to support your answer.

Dimensional analysis is used to convert one unit to another by multiplying with a conversion factor. Dimensional analysis is used when converting molecules to grams; moreover, you do so by multiplying the amount of molecules by 1 mole divided by 6.02x10^23, then multiplying that answer by the molar mass of the molecules divided by 1 mole. Dimensional analysis is also used when converting moles to particles. This is done by multiplying the total amount of moles by 6.02x10^23 divided by 1 mole. Furthermore, dimensional analysis is used to convert the amount of a gas at STP to moles. This is achieved by multiplying the amount of gas at STP in liters by 1 mole divided by 22.4 liters. Overall, Dimensional analysis is used in a wide range of ways to convert units, from converting molecules to grams, to converting moles to particles, and more.

At the time of Antoine Lavoisier, what did scientists think happened to a substance when it burned? How did Antoine Lavoisier disprove this idea? What law did his ideas lead to? Use details to support your answer.

During the time of Antoine Lavoisier, people believed that when a substance was burned it disappeared; moreover, they thought that when something evaporated it disappeared as well. Antoine Lavoisier disproved this idea by proving the Law of Conservation of Mass. This law states that matter cannot be created or destroyed but only changed into a new form. By discovering the Law of Conservation of Mass, Lavoisier discovered oxygen and that when oxygen is inhaled it is exhaled as carbon dioxide, which is then taken in by plants and then given of from plants as oxygen. The Law of Conservation of Mass majorly contributed to science and is the main basis for balancing chemical reactions and balancing cycles in ecosystems.

is the balanced reaction for the formation of table salt. Given 20 grams of Na(s) and 10 grams of Cl2, which reactant is in excess? How much NaCl should be produced from these amounts of the two reactants? Show all your work

First, determine the limiting reactant. 20 g Na⋅1 mol Na/22.99 g Na⋅2 mol NaCl/2 mol Na⋅58.44 g NaCl/1 mol NaCl=50.84 g NaCl 10 g Cl2⋅1 mol Cl/270.9 g Cl2⋅2 mol NaCl/1 mol Cl2⋅58.44 g NaCl/1 mol NaCl=16.49 g NaCl Chlorine is the limiting reactant, so sodium is in excess. 0.29 mol of NaCl will be produced when there is 10 g of Cl2, which makes 16.49 grams of NaCl.

Describe how to separate a mixture of salt, sand, and iron. Describe each step and what part of the mixture is separated out with that step.

First, run a magnet over the mixture. The magnet will attract the iron and take it out of the mixture. Next, put the salt and sand mixture in water and stir. The salt will dissolve in the water. Pour this mixture through a funnel with filter paper. The water and salt will go through the filter paper, and the sand will get caught by the filter. This separates out the sand. The last step is to evaporate the water, which will leave the salt behind.

Some rocket engines use a mixture of hydrazine, N2H4, and hydrogen peroxide, H2O2, as the propellant. The reaction equation is N2H4(l)+2 H2O2(l)→N2(g)+4 H2O(g). Which is the limiting reagent in this reaction when 0.750 mol N2H4 is mixed with 0.500 mol H2O2?

H2O

What is the percent composition of hydrogen in H2O2, hydrogen peroxide?

Hydrogen peroxide is approximately 6% hydrogen.

A 78.0 g sample of gold at 175∘C is put in a foam cup calorimeter with 25.0 g of water at 25.0∘C. Calculate the specific heat of the gold if the final temperature is 38.18∘C and the specific heat of water is 4.18 Jg∘C. Show your work.

If a 78.0 g sample of gold at 175°C is put into a foam cup calorimeter with 25.0 g of water at 25.0°C, the final temperature is 38.18°C, and the specific heat of water is 4.18 J/g°C, then the specific heat of the gold will be 0.129 J/g°C. Water: C= 4.18 J/g°C Ti= 25°C Tf= 38.18°C m= 25 g 𝚫T= 38.18-25= 13.18 Gold Sample: Ti= 175°C Tf= 38.18°C m= 78.0 g 𝚫T=38.18-175=-136.82 m⋅c⋅ΔT=-m⋅c⋅ΔT (25)(4.18)(13.18)=-(78.0)(C sample)(-136.82) 1377.31=10671.96 C sample 1377.3110671.96=10671.9610671.96C sample 0.129J/g°C=C sample

What is the difference between high and low pressure?

In high pressure, there are more particle collisions happening than in low pressure.

What happens when the correct amount of carbon is added to iron to make carbon steel?

It becomes more durable and stronger.

Why is the neutron to proton ratio so important?

It determines the stability of the nucleus based on the shielding effect of the neutrons

An electric motor produces energy to turn a fan blade. The energy used to turn the fan blade is always less than that produced by the motor. Where does the remainder of the energy go?

It is converted to heat.

What type of bond is the bond between two hydrogens (H-H)? Why?

It is non-polar because the atoms in the bond are the same, so they have the same electronegativity.

Which of the following compounds is likely to add hydroxide ions to a solution?

KOH

Which of the following compounds is likely to have a pH above seven?

KOH

Explain Le Chatelier's principle as it relates to chemical equilibrium. Describe the types of stresses that cause chemical reactions in equilibrium to make more products. Use details to support your answer.

Le Chatelier's principles states that a system will change in order to relieve stress when stress is applied to a system that is in dynamic equilibrium. A change in concentration, temperature, or pressure will disturb the equilibrium of a chemical system by causing molecules to collide more, or increasing the rate of reaction, which will cause the system to shift left or right. A system will adjust in order to minimize the effects of the stressor. For example, if more of a reactant was added into a chemical reaction, then more collisions would occur and more of the product is produced, causing the reaction to shift to the right. This means that conversion of products and reactants no longer occurs at the same time, so the system is no longer in a state of equilibrium.

Determine the base type for PCl3.

Lewis

Which of the following interactions would be the weakest?

Li+ and C3H8

Which statement is not evidence for the wave-particle duality of light?

Light travels at a constant speed in the vacuum of space.

Electromagnetic radiation can be separated into several types, but the types exist on a spectrum. The wavelength, frequency, and energy of a wave changes as you move through the spectrum, but speed stays constant. Describe the trends in wavelength, frequency, and energy of the parts of the electromagnetic spectrum as you move from radio waves to gamma rays. Use details to support your answer.

Looking at the parts of the electromagnetic spectrum as a whole allows you to see the trends in the properties that each part of the spectrum has. Radio waves have the least amount of energy, the longest wavelength, and the lowest frequency. As you move through the parts of the spectrum to gamma rays, the energy carried on the wave increases, the wavelength decreases, and the frequency increases. This means that gamma rays have the most energy, the shortest wavelength, and the highest frequency of the parts of the electromagnetic spectrum.

What is the formula for this compound: nitrogen trihydride? N3H

NH3

Why do you cook with metal pots and pans?

Metal has a low heat capacity, which allows it to heat up faster and transfer the heat to the contents of the pot or pan.

Answer the question below. Use the rubric in the materials for help if needed.List all of the possible mole ratios in the decomposition of silver oxide. 2Ag2O→4Ag+O2Explain what mole ratios help you to do. Use details to support your answer.

Mole ratios are conversion factors that allow you to convert the unit of one substance, to another unit by dimensional analysis. The mole ratio is determined by the coefficient in front of the element or compound. In the equation, for every 2 moles of silver oxide broken down, 4 moles of silver will be produced; therefore, the mole ratio is 2:4, or 1:2. The mole ratio for silver oxide to oxygen is 2:1, or for every 2 moles of silver oxide broken down, 1 mole of oxygen will be produced. For every 4 moles of silver produced, there will also be 1 mole of oxygen produced, moreover, the mole ratio of silver to oxygen is 4:1.

What preliminary work is not necessary to complete before performing a mass to mass stoichiometric problem?

Multiplying the coefficient by the molar mass

which of the following is an isotope of N-16

N-14

The combustion of glucose is represented by the following balanced equation: C6H12O6+6 O2→6 H2O+6 CO2.Which reactant is the limiting reagent if there is 1 gram of both C6H12O6 and O2?

O2

Which of the following diatomic molecules is joined by a double covalent bond?

O2

What is the best definition of an electric dipole?

Opposite charges are a fixed distance from each other.

Anna is excited about conducting her lab today. She takes out her lab sheet and reads over the lab. She gathers all of the lab materials. She follows each lab procedure step by step until she has completed the procedure and recorded all of the data she collected. After, Anna takes two of the substances and mixes them together to see what will happen. Which lab safety rule did Anna break?

Perform only experiments that you teacher tells you to perform

Using the stock name method when naming a transition metal ion that can have more than one common ionic charge, the numerical value of the charge is indicated by a _____.

Roman numeral following the name

What formula is used to represent the compound sulfur hexafluoride?

SF6

In the equation 4 Si2H3+11 O2→8 SiO2+6 H2O, what would be the activated complex?

Si2H302

Find the empirical formula for a compound with 65.4%C, 5.5%H, and 29.1%O.

The empirical formula is C3H3O.

Find the empirical formula for a compound with 92.25% C and 7.75% H.

The empirical formula is CH.

Find the empirical formula for a compound with 27.5%K, 37.5%Mn, and 35%O.

The empirical formula is K5Mn5O16.

Explain the meaning of the abbreviation STP and why scientists have to use it in their calculations with gases. Use details to support your answer.

The abbreviation 'STP' stands for standard temperature and pressure. Scientists use STP to specify pressure and temperature when dealing with gases. This is due to the fact that the volume of gas changes when pressure and temperature change. The standard temperature used is 0 degrees celsius and the pressure is 1 atmosphere. 22.4 L of gas at STP is equivalent to 1 mole.

Which of the following is not a type of chromatography?

solid chromatography

how have experiments been used to discover information about the atom when the atom cannot be seen

The behavior of particles in different experiments can be used to learn about atoms and the parts that make them up.The Cathode Ray Tube experiment showed that atoms contain charged particles. It used magnetic plates to determine the charge on these particles. The particles could not be seen, but their behavior allowed scientists to determine that they were negatively charged.The Gold Foil experiment was used to show that atoms are made of mostly empty space and have a mass core called a nucleus. This was also determined based on the behavior of particles that could not be seen.The Atomic Emission Spectrum experiment showed that electrons are positioned in fixed energy levels and can move from energy level to energy level if energy is added or released in the atom. This also gave information about atoms. Even though the electrons could not be seen, the results of their behaviors could be seen.

Describe the process used to determine how many atoms of each element are in 2Ca3(PO4)2. Show all your work.

The compound 2Ca3(PO4)2 has subscripts, coefficients, and a subscript outside of a parenthesis, all of which determine the amount of atoms of a specific element in a compound. A subscript, which is the smaller number following an element tells how much of an element is in the compound. This means that there are three atoms of calcium. However, there is coefficient in front of calcium, a coefficient is used to balanced an equation and is multiplied by the subscript. So, that means that there are six atoms of calcium present. The phosphate, or PO4, is in parenthesis, this means that each element will be multiplied by the subscript following the parenthesis. One multiplied by two is two, therefore, there are two atoms of phosphorus present. There are eight atoms of oxygen, because four multiplied by two is eight. By using coefficients, subscripts, and subscripts following a parenthesis, we can determine that in the compound, there are six atoms of calcium, two atoms of phosphorous, and eight atoms of oxygen.

Determine the concentration of a solution that has 3 moles of C6H12O6 dissolved in 9 liters of water. 27 M C6H12O6

The concentration of the solution is 1/3 M C6H12O6.

Determine the concentration of a solution that has 116.88 grams of NaCl dissolved in 1 liter of water.

The concentration of the solution is 2 M NaCl.

Looking at the electron dot structures for carbon dioxide below. Choose the one that is correct, and explain why it is correct based on the six rules for drawing covalent structures.

The correct electron dot structure for carbon dioxide is figure C based on the six rules for drawing covalent structures. In figure C the correct amount of valence electrons to be distributed is present for each atom; moreover, oxygen has six valence electrons and carbon has four valence electrons. The structure of figure C is correct, the least electronegative atom is in the center and the dot structure is symmetrical. Carbon is bonded to both oxygen's with a double bond that uses all four of its electrons and two valence electrons from each oxygen. This leaves behind eight valence electrons that are distributed equally to the outside atoms. Finally, the electron dot structure C satisfies the octet rule

Calculate the enthalpy change for the reaction 2K+S→K2S using the following thermochemical reactions.K+S→KS ΔH=+32.5 kJKS+K→K2S ΔH=+38.2 kJShow all your work.

The enthalpy change for the reaction 2K+S--> K2S is 𝚫H=+70.7 kJ. K+S→KSΔH=+32.5kJ KS+K→K2SΔH=+38.2kJ 2K+S→K2S 32.5kJ+38.2kJ=70.7kJ 2K+S→K2SΔH=70.7kJ

Use the first law of thermodynamics to explain why a cup of hot chocolate or tea eventually cools down if it sits on a table. Use details to support your answer

The first law of thermodynamics says that the energy of the universe is constant. This means that energy is always flowing from one system to another. Energy will seek to reach equilibrium when two systems, like the cup of hot liquid and the air around it, are in contact. The high-energy particles in the hot liquid and cup will bump into the lower-energy particles in the air around it. The high-energy particles will lose energy and the lower-energy particles will gain energy. This interaction will continue until the hot liquid and cup are the same temperature as the air around it.

Determine the freezing point depression of 2 kg of water when 2 mol salt is added to it. The Kf of water is 1.86∘Cm. Show all your work.

The freezing point depression of 2 kg of water will not change when 2 moles of salt is added to it. Na= 23 x 1= 23 g/mol Cl= 35.45 x 1= 35.4g/mol NaCl= 58.45 g/mol m= 2 mol/ 2 kg= 1 ΔTf= Kf x m ΔTf=(1.86)(1)= 1.86

What is the frequency of a wave that has a wavelength of 28 m? Remember that c=2.998⋅108 m/s.

The frequency of the wave is 1.07⋅107 Hz.

When can the ions in an ionic compound separate from each other?

The ions in an ionic compound can separate from each other when they dissolve in water.

Put the states of matter in order from slowest to highest particle speed

solid, liquid, gas

An ice cube is placed in a sealed insulated container of hot water at 80°C. After five minutes, the ice cube disappears.

The hot water lost the same amount of heat energy as the ice cube gained.

Choose the property that is typical of acids.

taste sour

Use the kinetic molecular theory to explain the effect that temperature has on viscosity of liquids. Use details to support your answer

The kinetic molecular theory explains that a substance's behavior is based on the behavior of it's molecules. The theory has certain assumptions, however, not all of these assumptions are true. The main assumptions of the theory state: molecules are constant random motion, collisions between molecules are elastic, molecules do not interact with one another besides colliding, and the distance between molecules is greater than the molecule's size. This theory can be used to explain the effect temperature has on viscosity, or the amount of resistance a liquid has to flow. Viscosity is the result of a strong attraction between particles, causing the liquid to flow at a slower rate; in turn, this goes against the kinetic molecular theory that says molecules are not attracted to one another. If a liquid with a high viscosity is heated, the particles will move faster and the liquid will flow more easily. However, if this same liquid is chilled, the particles will slowly and the liquid will have a higher viscosity. For example, when maple syrup is kept in the fridge, it will have a higher viscosity and will be harder to pour. But, if the maple syrup is stored in a pantry, the viscosity will be lower and it will be easier to pour. This is because when a liquid is heated, the bond between the particles is harder to maintain, so the attraction is weaker.

Why are the particles in a solid assumed to be moving even though we cannot see them?

The kinetic molecular theory says that all particles are in constant, random motion.

After analyzing the molecule name and formula, explain the similarities and differences between carbon dioxide (CO2) and carbon monoxide (CO). Use examples to support your answer.

The main difference between the two binary molecular compounds, CO2 and CO, is the amount of oxygen in their make up. Carbon dioxide has 2 two oxygens; furthermore, this is evident in its formula by the subscript following oxygen and the prefix 'di-' in front of oxygen in its name. Carbon monoxide only has one oxygen. The different amount of oxygen in both molecules is what causes their different properties. There are also similarities between the two. CO2 and CO are both binary molecular compounds, meaning they are made up of two elements and are both non-metals.

Describe the purpose of the electron dot diagram and how it works. Be sure to support your response with evidence from the text.

The main purpose of an electron dot diagram is to show the number of valence electrons an element has using dots around the element's symbol. For example, if an element has 4 electrons then dots that represent those electrons will be placed at the top of that elements symbol, at the bottom of that elements symbol, and then on the left and the right of that elements symbol, adding up to a total of 4 valence electrons. Another element has 6 valence electrons, 2 dots that represent those electrons will be placed at the top of the elements symbol, 1 dot will be placed at the bottom, and 1 dot will be placed on the left and the right of that elements symbol, adding up to 6 valence electrons. There can only be two valence electrons on each side of the elements symbol, however two dots cannot be present until each side has at least 1 electron. In total, 8 valence electrons can be shown using the electron dot diagram, this is because once an atom has 8 valence electrons it will satisfy the octet rule and be stable.

What does it mean for a metal to be malleable?

The metal can change shape and bend.

A compound is made up of 80.0% C and 20.0% H. Its molar mass is 30.0 g. What is its molecular formula?

The molecular formula is two times the empirical formula, so the molecular formula is C2H6.

Why does an ionic bond transfer electrons instead of sharing?

The non-metal is so much more electronegative than the metal that it pulls the electron away from the metal.

Valence electrons play a vital role in how atoms follow the octet rule. Describe the role that valence electrons play in the octet rule. Be sure to support your response with evidence from the text.

The octet rule states that atoms want to have eight valence electrons in order to be stable. Valence electrons are the electrons located in the outermost shell of an atom and are the electrons that are involved in chemical reactions. In order for atoms to satisfy the octet rule they will gain, give away, or share their valence electrons. For example, an atom that has 5-7 valence electrons will gain electrons, an atom with 1-3 valence electrons will lose electrons, and atoms with 4 valence electrons will share their electrons. Losing and gaining valence electrons will also change an atoms charge. For example, if Potassium, an atom with 1 valence electron, gives away its electron to Chlorine, who has 7 valence electrons, then Potassium becomes positive and Chlorine becomes negative. This is because when an atom gives away its valence electrons there are more protons than electrons, so the atom becomes positive; moreover, if the atom gains electrons, it becomes negative because there are more electrons than protons.

The purpose of the mole ratio in mass to mass stoichiometric problems is to _____

The purpose of the mole ratio in mass to mass stoichiometric problems is to _____

What is the ΔH of the reaction 2KS+2K→2K2S?K+S→KS ΔH=+32.5 kJ

The reaction is doubled, so the ΔH is found by doubling the enthalpy. The enthalpy of the reaction is +38.2 kJ⋅2=+76.4 kJ.

What is the ΔH of the reaction KS→K+S?K+S→KS ΔH=+32.5 kJ

The reaction is reversed, so the ΔH is found by reversing the sign of the enthalpy. The enthalpy of the reaction is -32.5 kJ.

How many moles of H2O2 are produced in the production of hydrogen peroxide when 13 grams of oxygen are used?2 H2O+O2→2 H2O2

The reaction produces 0.81 mol H2O2 when 13 g O2 are used.

Reactions that occur in the gaseous state are affected by changing the volume of the container. Which choice best describes what will happen to the reaction if the volume of the container is decreased

The reaction will shift right.

Calculate the speed of light in a sugar solution. The index of refraction for the sugar solution is 1.33. Remember that the speed of light is 2.998⋅108 m/s.

The speed of light in a sugar solution is 2.25⋅108 m/s.

Calculate the speed of light in a diamond. The index of refraction in diamond is 2.417. Remember that the speed of light is 2.998⋅108 m

The speed of light in a diamond is 1.240⋅108 m/s.

What is the wavelength of a wave that has a frequency of 6.1⋅109 Hz? Remember that c=2.998⋅108 m/s.

The wavelength of the wave is 0.049 m.

How many moles are represented by 3.01⋅1023 helium atoms?

There are 0.50 moles of helium when there are 3.01⋅1023 atoms present.

How many moles are present in 25.2 grams of water?

There are 1.40 moles in 25.2 grams of H2O.

How many particles are present in 0.24 moles of carbon?

There are 1.4⋅1023 particles of carbon when there are 0.24 moles present.

How many moles are represented by 9.34⋅1021 sodium atoms?

There are 1.55⋅10-2 moles of sodium when there are 9.34⋅1021 atoms present

Determine the molar mass of zinc nitrate, Zn(NO3)2.

There are 189.39 grams per mole of zinc nitrate

How many moles of hydrogen gas are present in 65.0 liters at STP?

There are 2.90 moles of hydrogen gas present in 65.0 liters at STP.

The sugar in your kitchen has a molar mass of 342.3 g/mol. How many particles are present inside a sugar bowl if there are 250 grams of sugar in it?

There are 4.4⋅1023 particles in the bowl that contains 250 grams of sugar.

How many particles are present in 13.4 moles of carbon dioxide? 6.02⋅1024

There are 8.07⋅1024 particles of carbon dioxide when there are 13.4 moles present.

Determine the number of moles that are represented by 5.82⋅1028 gold atoms.

There are 9.67⋅104 moles of gold when there are 5.82⋅1028 atoms present.

Why do metals have body-centered, face-centered, and hexagonal-centered structures?

These structures give metals their strong properties and also cause them to be rigid.

How is the energy released from a system related to the energy absorbed by the surroundings?

They are the same.

When copper metal is added to silver nitrate in solution, silver metal and copper (II) nitrate are produced. What mass of silver is produced from 100.0 g Cu?Cu(s)+2(AgNO)3→2(Ag)(s)+Cu(NO3)2

You will produce 339.5 g Ag from 100.0 g Cu.

Casey is ready for lab. He has on all necessary lad attire. He looks at his procedure and sees that it tells him to use a test tube to conduct a reaction. The test tube will need to be heated. Casey picks up the test tube, places the necessary substances inside, and heats the test tube. Which lab saftey rule did Casey break?

Thoroughly inspect glassware before each use. Never use chipped or cracked glassware. Never use dirty glassware.

Jordan was asked to find the density of an irregular-shaped object in the science lab. She finds that the volume is 4.56 ml, and the mass is 128 g. Describe how she could find the volume when the object is an irregular shape. Also, show how to calculate the density, giving the answer with the correct number of significant digits. Use details to support your answer.

To find the volume of an irregular-shaped object, she would use water displacement. She would put a certain amount of water in a graduated cylinder, and measure it. Then. she would drop the object into the water and read the measurement of the water again. She would then subtract the two measurements to get the volume of the object.The density of this object is 28.1 g/ml. This comes from dividing the mass by the volume. The mass is 128 g, and the volume is 4.56 ml. Dividing 128 g by 4.56 ml gives 28.07 g/ml. The numbers for mass and volume both have three significant digits, so the answer should have three significant digits. The answer is 28.1 g/ml.

What is the mass of 1.368⋅1024 particles of table salt? Table salt has a molar mass of 58.44 g/mol.

Use dimensional analysis to solve this problem. 1.368⋅1024 particles⋅1 mol/6.02⋅1023 particles⋅58.44 g/1 mol=132.8 g There are 132.8 grams in 1.368⋅1024 particles of table salt.

Compare and contrast alpha, beta, and gamma radiation. For each, detail the emitted particles, released energy, and danger to humans. Use details to support your answer.

When an element's nucleus is unstable, it will break apart and emit radiation. Alpha radiation is the largest particle that can be emitted, and it contains two protons and two neutrons. Alpha particles have the least amount of energy and cannot pass through a piece of paper. Beta particles are smaller than alpha particles and consist of a single electron. These types of particles do not have enough energy to penetrate our skin. Gamma radiation is the smallest particle and has the highest energy. Gamma rays do not have any mass. They are packets of energy. Gamma rays have so much energy that they can only be stopped by lead or thick concrete, so they are dangerous to humans.

After analyzing the molecule name and formula, explain the similarities and differences between carbon dioxide (CO2) and carbon monoxide (CO). Use examples to support your answer.

While CO2 and CO both involve carbon and oxygen, there are different amounts in each compound. The amount in each compound can be determined by looking at the prefix in their names and the number that goes with that prefix. For example, CO2 is carbon dioxide. The prefix di- means two and since it is placed in front of oxygen, you can deduce that there are two oxygen atoms present in the compound. Carbon monoxide, or CO, has only one oxygen atom present, this is because the prefix mono-, meaning one, is placed in front of oxygen. Using prefixes when naming binary molecular compounds helps to describe the amount of each element in the compound and helps to show the difference in the composition of many compounds, such as CO2 and CO.

The chemical properties of an element are largely determined by _____.

the number of valence electrons the element has

How many grams are needed to make a solution that is 5 M HCl when you have 500 milliliters of water?

You need 91.15 g HCl to make the solution.

Laughing gas (nitrous oxide, N2O) is sometimes used as an anesthetic in dentistry. It is produced when ammonium nitrate is decomposed according to the following reaction.NH4NO3(s)→N2O(g)+2H2O(l) How many grams of water are produced in the reaction above if you start with 33 grams of nitrous oxide?

You will produce 27.0 g H2O from 33.0 g N2O.

Which device to nutritionists use to determine the number of calories in samples of food?

a bomb calorimeter

Which device can be used to determine the amount of heat absorbed by the surroundings in a reaction?

a calorimeter

. Colligative properties include freezing point depression, boiling point elevation, and vapor pressure lowering. What is the best description of a colligative property?

a change in the properties of a solvent after a solute is added

If a pH value goes up or down by one number, how much does the concentration of the H+ ions change?

a factor of 10

the filtration technique is used to separate ---

a liquid from a solid

What types of mixture does this picture represent (image is of two yellows square bonded together and a single red square floating around)

a mixture of elements

what does this picture represent (a single red squares and single blue squares)

a mixture of elements

Choose the best description of a reversible reaction.

a reaction that occurs in both directions at the same time

What is an activated complex?

a short-lived, very unstable compound that is formed for a split second before breaking into the products

What is a saturated solution?

a solution where the maximum amount of solute is dissolved in the solvent

which of the following explains the different between a theory and a law

a theory explains why something happens, and a law states what happens

What is the chemistry definition of a mole?

a unit used to measure an extremely large quantity of things

Which of the following describe the particles of a substance that is an element

the particles are all the same and all separate

In order for it to be falsifiable it needs to be -------

able to be proven false

What is the theoretical temperature where all particle motion would stop?

absolute zero

chromatography relies on --- for separating components of a solution

the polarity of the components

Which group of elements can form more than one cation and are classified as Type II cations?

transition metals

If a nucleus is too large, which type of particle will it most likely emit?

alpha particle

Which of the following is a definition for an interstitial alloy?

an alloy in which the atomic sizes of the components are different

which of the following cannot be directly read from the periodic table

an elements number of neutrons

Which type of reaction is indicated by a positive ΔH?

an endothermic reaction

Which statement best describes boiling point elevation?

an increase in the boiling point of a solvent when a solute is added to it

Which type of substance causes greater vapor pressure lowering?

an ionic compound

List lab equipment and tools in a complete list that are needed to heat a reaction in a beaker with high heat

beaker, ring stand, iron ring, bunsen burner, beaker tongs, and wire gauze

Which of the following is the best reason scientists use significant digits

because each measuring device has a different level of accuracy

All gases _____.

behave differently based on temperature and pressure

What is the molecular shape of the sulfur dioxide (SO2) molecule?

bent

If a nucleus needs to decrease its neutrons and add a proton to become more stable, which type of particle will it most likely emit?

beta particle

Sulfur hexafluoride is an example of a

binary compound

Sulfur hexafluoride is an example of a _____.

binary compound

Under what conditions can potassium bromide, an ionic compound, conduct electricity?

when melted or dissolved in water

Which position of two atoms has the highest repulsion between the nuclei?

when there is no distance between them

Is this compound an acid or a base: H2O?

both

How is a supersaturated solution typically made?

by heating a solution to dissolve more solute, then letting it cool

What is the name of the base Ca(OH)2?

calcium hydroxide

in democritus' concept of an atom, what did 'atom' mean

cannot cut

How are chemical formulas of binary ionic compounds generally written?

cation of the left, anion of the right

In the specific heat equation, what unit must temperature be?

celcius

Jordana pulled a muscle while running at a track meet. Her coach gave her a self-heating pack to treat the injury. The instructions on the box said to twist the pack until the liquids mix. Which type of energy contained in the pack is responsible for producing the heat?

chemical

Once a reaction is proceeding both forward and backward at the same rate, which state has been reached?

chemical equilibrium

The numbers in front of the compounds in an equation are called _____.

coefficients

the role of the filter paper in the filtration process is to --

collect all of the solid particles

Identify this reaction.C3H8+O2→CO2+H2O

combustion

What types of matter does this picture represent (a triple bond of a yellow square and 2 blue square)

compound

The purpose of the mole ratio in mass to mass stoichiometric problems is to _____.

convert from the given substance to the desired substance using dimensional analysis

Which law is used to determine the energy of interaction between two ions

coulombs law

Who was the first to come up with the idea of an atom

democritus

Density equation

density= mass/volume

The name of As2S5 is _____.

diarsenic pentasulfide

Distillation separates solutions using --

differing boiling points of the compounds

Using prefixes, name this molecule: H2O.

dihydrogen monoxide

According to Charles' law, what kind of relationship does temperature and volume have?

direct relationship

Which of the following is not a common pH indicator?

distilled water

Identify this reaction.HCl+NaOH→NaCl+H(OH)

double displacement

Boiling water on the stove for cooking can be classified as a(n) _____ process.

endothermic

The quantum mechanical model of the atom is also called the --

electron cloud model

A pure substance could be an

element and compound

which of the following are considered pure substances

elements and compounds

A glass of ice water is placed on a table on a hot afternoon. Condensation forms on the outside of the glass. What best describes the formation of condensation?

exothermic

A sample of gas is kept at 5 atmospheres, 25∘C, and takes up 3 L. If the gas is cooled, the volume changes to 1.5 L and the pressure changes to 4 atmospheres, what is the final temperature in degrees Celsius? Show all your work.

final temp is -153.8 degrees c

What property of liquids allows them to take the shape of their containers?

flow

What is the element with the highest electronegativity value

fluorine

Which of the following correctly provides the name of the element, the symbol for the ion, and the name of the ion?

fluorine, F-, fluoride ion

Why did Dimitri mandeleev leave open space on his periodic table

for elements that were yet to be discovered

At which stage of the scientific process would a scientist look at experimental data from other scientists to set up a new experimental study?

forming a hypothesis

When two systems are in contact with each other, energy will move between them to reach equilibrium. How does the energy between the two systems move?

from the higher-energy system to the lower-energy system

Which component is not typically found in a nuclear reactor facility

fusion reaction

The kinetic molecular theory can help us determine which state of matter has the fastest moving particles. Choose the correct state of matter.

gas

put the states in order from lowest to highest attractive force between the particles in an object

gas, liquid, solid

the experiment that showed that atoms are mostly empty space with a central core of mass called the nucleus was the ---

gold foil experiment

Which of the following is not a property of an acid?

good at removing grease

The best instruments to use to measure volume in the lab is a ---.

graduated cylinder

what evidence did dalton have to prove his theory

he did not have any evidence to prove his theory

What causes some parts of the electromagnetic spectrum to be harmful to humans?

high energy

What is the frequency of a wave?

how many times a wave is repeated during a certain interval of time

Which of the following changes will not speed up the rate at which a solute dissolves in a solvent?

increasing the particle size

Which nuclide is written in isotope notation? 818

iron-58

A resonance structure _____.

is a structure that can have more than one electron dot formula

A beaker cannot be used for measuring the volume of a liquid because ---.

it does not have precise measuring lines

What describes a scientific theory

it may change; theories change as more knowledge is gained

What happens to an ionic compound when it is hit with a hammer?

it shatters

How does this equation help you to understand acids and bases: H(aq)++OH(aq)- ↔H2O(aq)?

it shows you that water is a reversible reaction, which contains hydrogen and hydroxide ions

how does ionization energy change from left to right across a period in the periodic table

it tends to increase

who used the word atom 2,200 years ago after democritius first used it

john dalton

When an ionic compound like potassium chloride is formed, which part of the reaction will release the most energy?

joining the potassium and chloride ions to make KCl

A school bus uses petroleum as chemical potential energy. This energy is transferred through the engine, which in turn moves the bus. The movement of the bus is an example of what type of energy?

kinetic

book held 1 meter above the floor has potential energy. The book is dropped and hits the floor. To what types of energy has the potential energy of the book been converted?

kinetic, sound and heat

Which of the following is not an example of a base?

lemon

Refraction causes many phenomena in our everyday lives. Which phenomena is not caused by refraction?

light bending around an object

What is the electron geometry of the nitrogen (N2) molecule?

linear

Chromatography can be used to separate

liquid-liquid mixtures; gas-gas mixtures

heat capacity depends on

mass

which of the following physical changes is an endothermic change

melting

which of the following is a chemical change

milk turning sour

Which type of energy is not considered an evolving source of energy?

nuclear

A chemical formula that shows the actual number and kinds of atoms present in one molecule of a compound is its _____.

molecular formula

. Use the band of stability to determine if 154/63 Eu is a stable or unstable nucleus.

n/Z= 1.44, stable

What is the charge of an ionic compound?

neutral

Most polyatomic ions will only contain _____.

non-metal atoms

Which scenario is Hess' law not used for?

o calculate the amount of heat lost by a sample of metal in a calorimeter

Each color of the visible light spectrum has a different frequency and wavelength. Which color listed below has the longest wavelength and the lowest frequency?

orange

What element did Antoine Lavoisier discover?

oxygen

Which mathematical relationship shows Gay-Lussac's law?

p1/t1 = p2/t2

The combined gas law uses multiple variables to show the relationship between the volume, the pressure, and the temperature of gases. What is the mathematical relationship between these three variables? T1P1V1=T2P2V2

p1v1/t1=p2v2/t2

Explain what the pH scale can tell you about an acid, base, or neutral substance like distilled water. Use details to support your answer.

pH scale will measure the concentration of hydrogen in a substance, this means that it can identify whether a substance is an acid or a base. The pH scale goes from 0-14 and when moving up and down the scale, it will increase or decrease by ten from each number. For example, an acid with a pH level of 1 is 10 times more acidic than an acid with a pH level of 2 and 100 times more acidic than an acid with a pH level of 3. An acid has a higher concentration of H+ ions and anything that falls between 0-7 on the pH scale is an acid. A base has a higher concentration of OH- ions and anything that falls between 7-14 on the pH scale is a base. Moreover, if a substance is neutral, such as distilled water, it will have a pH level of 7. The pH of a substance can be tested with a pH meter, that can only give values as a whole number, or an indicator that will change color based on the pH level; however, indicators do leave room for human error.

Chromatography separates mixtures based on _____.

polarities

why subatomic particles make up the mass of an element

protons and neutrons

which of the following was not part of the atomic emission experiment

protons and neutrons are in the nucleus of the atom

What property allows prisms to bend and separate light?

refraction

How much distance is between particles according to the kinetic molecular theory

relatively large compared to their size

A student did an experiment on the rate of the reaction of vinegar and baking soda. The data this student collected led him to conclude that reactions occurred faster at lower temperatures. Another student tried the same experiment but found that the reaction occurred faster at higher temperatures. Which of the following criteria was not met regarding the idea that the reaction of vinegar and baking soda occurs faster at lower temperatures

repeatable

Put this equation into word form.Rb+P→Rb3P

rubidium and phosphorus react to form rubidium phosphide

which of the following is a misconception about science

science is just an accumulation of facts and data

What type of bond holds diatomic fluorine (F2) together?

sigma bond between p orbitals

Choose the property that is typical of bases.

slippery

Chemical formulas show the number and type of atoms in the _____ representation of a substance.

smallest

what is an example of a compound

sodium chloride (NaCl)

Which type of energy is not considered a traditional source of energy?

solar energy

When you dilute a solution, you need to add more _____ to the solution.

solvent

What is the hybridization of the carbon in the HCN molecule?

sp

Scientific Law (definition)

states an observation that is easily observed and accepted by the community

A scientific law

states the presence of a phenomena, does not explain why a phenomenon occurs, is completely accepted by the communit

Which method would help Oliver to dissolve sugar in his tea faster?

stirring the tea with the sugar in it

Put the elements in order from least to most electronegative

strontium, antimony, tellurium, iodine

Compare and contrast acids and bases. Use details to support your answer.

substance is either an acid, base, or neutral, this is determined by their pH. For example, on the pH scale 0-7 is acidic, 7 is neutral, and 7-14 is basic. Furthermore, things that are basic or acidic have specific properties that can identify them as a base or an acid. An acid will have a higher concentration of H+, or hydrogen ions, corrode metal, conduct electricity, and will taste sour. Pickles are an example of an acid that is stored in glass and tastes sour. On the other hand, a base has a higher concentration of OH-, or hydroxide ions, are slippery, corrosive, conduct electricity, and will taste bitter. Because bases are corrosive, they are good at removing dirt and grease from objects--things like soaps, degreasers, and shampoos are all bases. The defining characteristics of bases and acids set them apart and can help someone easily identify whether a substance is a base or an acid.

Which of the following is a homogenous mixture

sugar water

which element on the periodic table has 16 protons

sulfur

A glass of water is sitting on a table. what determine if that glass of water will undergo a phase change and evaporate

temperature and pressure

In order for something to be scientific, it needs to be ---,---,---, and ---.

testable, repeatable, observable, falsifiable

Specific heat is defined as _____

the amount of energy needed to raise the temperature of 1 gram of a substance by 1∘ C

what is niels bohr's model of the atom

the atom has a positively charged nucleus with negatively charged electrons orbiting in fixed rings

What is the basis of a metallic bond?

the attraction of metal ions to mobile electrons

Which law of thermodynamics can be rephrased to state that energy cannot be created or destroyed?

the first law

Amplitude of a wave is a measure of which property?

the height of the wave

which of the following gives the correct masses for the subatomic particles

the mass of protons and neutrons are both 1 amu, and the mass of an electron is about 0.0005 amu

If a reaction is exothermic, what will happen if the reaction is also heated?

the reaction will shift left

What causes visible light to bend and separate when it encounters a prism?

the shape and the material of the prism

what happens to the solid when the particle in a substance begin to move fast enough to break the attractive forces between the particle of the solid

the solid starts to melt

which of the following is a fundamental assumption on which science is based

the world is real, not a creation of the imagination

The idea that objects are attracted to each other because they create a dent in the fabric of time and space is a widely accepted explanation of gravity that is supported by abundant scientific evidence. This idea about gravity is a ---

theory

The density of a large piece of iron and a small piece of iron will be the same because

they are both made of iron; density is an intensive party

Which is true of the melting and boiling points for ionic compounds?

they are high

which of the following describes the physical state of gases but not the physical states of liquids or solids

they can fill the container they are in

What does a negative energy of interaction tell you about the attraction between two atoms?

they will attract

In which of the following are the name and formula given correctly?

tin (IV) fluoride, SnF4​​​​

which of the following statements describes a pair of isotopes

two atoms with the same number of protons, but a different number of neutrons

Binary molecular compounds are composed of which types of elements?

two non-metals

What mathematical relationship accurately models Charles' law?

v1/t1=v2/t2

The kinetic molecular theory assumes that particles are not attracted to each other. Which property of liquids proves this assumption untrue?

viscosity

A solution of 5 M HCl is already made. You need to dilute the solution to 1 M HCl. The 1 M HCl solution is _____.

weaker

What are ways to measure volume

with an equation, with a graduated cylinder, water displacement