anushri2 - AP Chem Final

Ch 5 Gas Laws: Out of all of the gases, the density (g/L) of the gas is

greatest in B

Ch 5 Gas Laws: The density of the gas, in g/L, is

greatest in B

CH8 - Describe Father and Tim's experience in Verplanck's Point.

ily

Chp 10 - Compared to the equilibrium vapor pressure of CH3OH(l) at 300 K, the equilibrium vapor pressure of C2H5OH(l) at 300 K is

lower, because London dispersion forces among C2H5OH molecules are greater than those among CH3OH molecules

Ch 5 Gas Laws: A sample of an unknown gas from a cylinder is collected over water in the apparatus shown above. After all the gas sample has been collected, the water levels inside and outside the gas collection tube are made the same. Measurements that must be made to calculate the molar mass of the gas include all of the following EXCEPT

mass of water in apparatus

ch-4:A student combines a solution of NaCl(aq) with a solution of AgNO3(aq), and a precipitate forms. Assume that 50.0mLof 1.0MNaCl(aq) and 50.0mL of 1.0MAgNO3(aq) were combined. According to the balanced equation, if 50.0mL of 2.0MNaCl(aq) and 50.0mL of 1.0MAgNO3(aq) were combined, the amount of precipitate formed would

not change, because the amount of AgNO3(aq) did not change

Ch 5 Gas Laws: When a sample of oxygen gas in a closed container of constant volume is heated until its absolute temperature is doubled, which of the following is also doubled?

pressure

Ch 5 Gas Laws: The pressure, in atm, exerted by 1.85 mol of an ideal gas placed in a 3.00 L container at 35.0°C is given by which of the following expressions?

(1.85)(0.0821)(308) / 3.00 atm

Ch8 - Bonding Based on the resonance structures shown above, what are the bond orders of the two carbon-oxygen bonds?

1.5 and 1.5

Ch 5 Gas Laws: A flask contains 0.25 mole of SO2(g), 0.50 mole of CH4(g), and 0.50 mole of O2(g). The total pressure of the gases in the flask is 800 mm Hg. What is the partial pressure of the SO2(g) in the flask?

160 mm Hg

Ch 5 Gas Laws: A sealed vessel contains 0.200 mol of oxygen gas, 0.100 mol of nitrogen gas, and 0.200 mol of argon gas. The total pressure of the gas mixture is 5.00 atm. The partial pressure of the argon is

2.00 atm

Ch 5 Gas Laws: An equimolar mixture of N2(g) and Ar(g) is kept inside a rigid container at a constant temperature of 300 K. The initial partial pressure of Ar in the mixture is 0.75atm. An additional amount of Ar was added to the container, enough to double the number of moles of Ar gas in the mixture. Assuming ideal behavior, what is the final pressure of the gas mixture after the addition of the Ar gas?

2.25atm , because doubling the number of moles of Ar doubles its partial pressure.

Ch-4 : Based on the half-reactions represented above, which of the following is the balanced ionic equation for the oxidation-reduction reaction between Al(s) and Sn2+(aq) ?

2Al(s)+3Sn2+(aq)→2Al3+(aq)+3Sn(s)

Ch 5 Gas Laws: A 2 L sample of N2(g) and a 1 L sample of Ar(g), each originally at 1 atm and 0°C, are combined in a 1 L tank. If the temperature is held constant, what is the total pressure of the gases in the tank?

3 atm

Ch 5 Gas Laws: When 6.0 L of He(g) and 10. L of N2(g), both at 0oC and 1.0 atm, are pumped into an evacuated 4.0 L rigid container, the final pressure in the container at 0oC is

4.0 atm

Ch 5 Gas Laws: The figure above represents three sealed 1.0 L vessels, each containing a different inert gas at 298 K. The pressure of Ar in the first vessel is 2.0 atm. The ratio of the numbers of Ar, Ne, and He atoms in the vessels is 2:1:6, respectively. After all the gases are combined in a previously evacuated 2.0 L vessel, what is the total pressure of the gases at 298 K?

4.5 atm

Ch 5 Gas Laws: Equal masses of He and Ne are placed in a sealed container. What is the partial pressure of He if the total pressure in the container is 6 atm?

5 atm

CH8 - The potential energy as a function of internuclear distance for three diatomic molecules, X2, Y2, and Z2, is shown in the graph above. Based on the data in the graph, which of the following correctly identifies the diatomic molecules, X2, Y2, and Z2?

A

CH8 - Which of the following diagrams best illustrates how a displacement in an ionic crystal results in cleavage and brittleness?

A

Ch 5 Gas Laws: The N2 particles in vessel 3 at 27°C are represented in the diagram above. The lengths of the arrows represent the speeds of the particles. Which of the following diagrams best represents the particles when vessel 3 is heated to 127°C?

A

ch-4:When students added 2.0g of NaI crystals to 100.mL of Pb(NO3)2(aq), a yellow precipitate formed. After the solution was filtered, the yellow solid was dried and weighed. Data from the experiment are shown in the table above. Which of the following claims is best supported by the observations?

A chemical change occurred when a yellow, insoluble compound with a larger mass than the original NaINaI formed.

Ch 5 Gas Laws: A gas mixture at 0°C and 1.0atm contains 0.010mol of H2, 0.015mol of O2, and 0.025mol of N2. Assuming ideal behavior, what is the partial pressure of hydrogen gas (H2) in the mixture?

About 0.20atm , because H2 comprises 20% of the total number of moles of gas.

ch-4: A student combines a solution of NaCl(aq) with a solution of AgNO3(aq), and a precipitate forms. Which of the following is the balanced net ionic equation for the formation of the precipitate?

Ag+(aq)+Cl−(aq)→AgCl(s)

CH8-Of the following diagrams, which best represents the structure of solid KF?

B

Ch 5 Gas Laws: Which flask contains the smallest number of moles of gas?

B

ch 4 - Which of the following identifies a conjugate acid-base pair in the reaction represented above?

B

CH8 - Has a central atom with less than an octet of electrons

BH3

ch-4:A student combined two colorless aqueous solutions. One of the solutions contained Na2CO3Na2CO3 as the solute, and the other contained HClHCl. The chemical reaction that took place is represented by the equation above. What experimental result would be evidence that a chemical reaction took place when the solutions were combined?

Bubbles formed when the two solutions were combined.

Chp 10 - The table above shows the structural formulas and molar masses for three different compounds. Which of the following is a list of the compounds in order of increasing boiling points?

Butane < acetone < 1-propanol

Ch 5 Gas Laws: Which flask contains the sample with the greatest density?

C

Chp 10 - The molecular formula and molar mass of two straight-chain hydrocarbons are listed in the table above. Based on the information in the table, which compound has the higher boiling point, and why is that compound's boiling point higher?

C4H10 , because it has more electrons, resulting in greater polarizability and stronger dispersion forces

Chp 10 - In which of the following liquids do the intermolecular forces include dipole-dipole forces?

CH2F2 (l)

CH8 - Each set of lettered choices below refers to the numbered statements immediately following it. Select the one lettered choice that best fits each statement. A choice may be used once, more than once, or not at all in each set. Refer to the following compounds. (A) CH3CH2CH2CH3 (B) CH3CH2CH2OH (C) CH3COCH3 (D) CH3COOH (E) CH3CH2CH2NH2 Is isomeric with CH3CH2CHO

CH3COCH3

Chp 10 - Based on the data in the table above, which of the following liquid substances has the weakest intermolecular forces?

CH3OH (l)

Ch 5 Gas Laws: The table contains information about samples of four different gases at 273 K. The samples are in four identical rigid containers numbered 1 through 4. On the basis of the data provided above, the gas in container 3 could be

CH4

Ch8 Bonding - On the basis of the information above, which of the following arranges the binary compounds in order of increasing bond polarity?

CH4 < SiCl4 < SF4

Ch 5 Gas Laws: A 2 L container will hold about 4 g of which of the following gases at 0°C and 1 atm?

CO2

For which of the following molecules are resonance structures necessary to describe the bonding satisfactorily?

CO2

Chp 10 - Based on the information in the table above, which liquid, CS2(l) or CCl4(l), has the higher equilibrium vapor pressure at 25°C, and why?

CS2 (l), because it has weaker London dispersion forces

CH8 - Of the following compounds, which is the most ionic?

CaCl2

CH8 - Which of the following substances has bonds with the greatest ionic character?

CaCl2

Chp 10 - Based on the structures shown above, which of the following statements identifies the compound with the higher boiling point and provides the best explanation for the higher boiling point?

Compound 2, because it forms hydrogen bonds, whereas compound 1 does not

Ch - 4 : When a zinc plate is placed in an aqueous solution of copper sulfate, elemental copper forms, as represented by the equation above. Which of the following represents the reduction half-reaction of the reaction?

Cu2+(aq)+2e−→Cu(s)

CH8 - Which of the following graphs correctly shows the relationship between potential energy and internuclear separation for two hydrogen atoms?

D

CH8- NH3 reacts with BF3 to form a single species. Which of the following structural diagrams is the most likely representation of the product of the reaction?

D

Chp 10 - In the diagram above, which of the labeled arrows identifies hydrogen bonding in water?

D

Chp 10 - Which of the following lists the substances F2, HCl, and HF in order of increasing boiling point?

F2 < HCl < HF

Ch-4: Which of the following represents the oxidation half-reaction based on the balanced ionic equation shown above?

Fe2+(aq)→Fe3+(aq)+e−

Ch 5 Gas Laws: A mixture of CO(g) and H2(g) is pumped into a previously evacuated 2.0 L reaction vessel. The total pressure of the reaction system is 1.2 atm at equilibrium. What will be the total equilibrium pressure of the system if the volume of the reaction vessel is reduced to 1.0 L at constant temperature?

Greater than 1.2 atm but less than 2.4 atm

Chp 10 - The London (dispersion) forces are weakest for which of the following gases under the same conditions of temperature and pressure?

H2

ch-4:A beaker was half filled with freshly distilled H2OH2O and placed on a hot plate. As the temperature of the water reached 100°C100°C, vigorous bubbling was observed in the beaker. The gaseous contents of the bubbles were analyzed. The presence of which of the following substances would support the claim that the observed phenomenon was a physical change?

H20(g)

CH8 - Has two lone pairs of electrons

H2O

CH8 - The electron-dot structure (Lewis structure) for which of the following molecules would have two unshared pairs of electrons on the central atom?

H2S

ch-4:Which of the following is the correct net ionic equation of the neutralization reaction between hydrofluoric acid and sodium hydroxide in aqueous solution?

HF(aq)+OH−(aq)→H2O(l)+F−(aq)

Chp 10 - Which of the substances listed above has the highest boiling point, and why?

HF, because its molecules form hydrogen bonds

Ch-4: Based on the Brønsted-Lowry theory of acids and bases, which of the following species can act as both a conjugate acid and a conjugate base?

HS−

Ch 5 Gas Laws: A 0.5 mol sample of He(g) and a 0.5 mol sample of Ne(g) are placed separately in two 10.0 L rigid containers at 25°C. Each container has a pinhole opening. Which of the gases, He(g) or Ne(g), will escape faster through the pinhole and why?

He(g) will escape faster because the He(g) atoms are moving at a higher average speed than the Ne(g) atoms.

Chp 10 - Which of the following is the strongest type of interaction that occurs between the atoms within the circled areas of the two molecules represented above?

Hydrogen bond

Ch8 Bonding - Which of the following has the bonds arranged in order of decreasing polarity?

H−F > N−F > F−F

CH8 - The melting point of MgO is higher than that of NaF. Explanations for this observation include which of the following? I. Mg2+ is more positively charged than Na+. II. O2- is more negatively charged than F-. III. The O2- ion is smaller than the F- ion.

I and II only

Ch 5 Gas Laws: A sample of an ideal gas is cooled from 50.0oC to 25.0oC in a sealed container of constant volume. Which of the following values for the gas will decrease? I. The average molecular mass of the gas II. The average distance between the molecules III. The average speed of the molecules

III only

Chp 10 - A sample of a hard, solid binary compound at room temperature did not conduct electricity as a pure solid but became highly conductive when dissolved in water. Which of the following types of interactions is most likely found between the particles in the substance?

Ionic bonds

Ch 5 Gas Laws: Equal masses of three different ideal gases, X, Y, and Z, are mixed in a sealed rigid container. If the temperature of the system remains constant, which of the following statements about the partial pressure of gas X is correct?

It depends on the relative molecular masses of X, Y, and Z.

Chp 10 - Which of the following correctly indicates whether the solid represented by the particulate model shown above conducts electricity and explains why or why not?

It does not conduct electricity because its ions cannot move freely within the solid.

Chp 10 - The diagram above is a molecular model of a gaseous diatomic element that is just above its boiling point. Intermolecular forces between the gas molecules will cause them to condense into the liquid phase if the temperature is lowered. Which of the following best describes how the model is limited in its depiction of the phenomenon?

It does not show how the temporary fluctuating dipoles of the molecular electron clouds result in a net force of attraction between the molecules.

ch-4:Which of the following best describes the process represented above that takes place when NH3 is added to water?

It is an acid-base reaction in which a proton is exchanged from H2O to NH3 .

ch-4:When the reaction represented above proceeds, heat is produced. Which of the following best describes the reaction?

It is an oxidation-reduction reaction because zinc is oxidized and hydrogen is reduced.

Ch 4 -Which of the following statements about the reaction represented above is correct?

It is an oxidation-reduction reaction, and Mg is oxidized.

ch-4:A student carried out a titration using HC2H3O2(aq) and NaOH(aq). The NaOH(aq) was added from a buret to the HC2H3O2(aq) in a flask. The equivalence point was reached when a total of 20.0mL of NaOH(aq) had been added to the flask. How does the amount of HC2H3O2(aq) in the flask after the addition of 5.0mL of NaOH(aq) compare to the amount of HC2H3O2(aq) in the flask after the addition of 1.0mL of NaOH(aq), and what is the reason for this result?

It is less because more HC2H3O2(aq) reacted with the base.

Chp 10 - The electron cloud of HF is smaller than that of F2 , however, HF has a much higher boiling point than F2 has. Which of the following explains how the dispersion-force model of intermolecular attraction does not account for the unusually high boiling point of HF?

Liquid F2 has weak dispersion force attractions between its molecules, whereas liquid HF has both weak dispersion force attractions and hydrogen bonding interactions between its molecules.

Chp 10 - In solid methane, the forces between neighboring CH4 molecules are best characterized as

London (dispersion) forces

CH8 - The lattice energy of a salt is related to the energy required to separate the ions. For which of the following pairs of ions is the energy that is required to separate the ions largest? (Assume that the distance between the ions in each pair is equal to the sum of the ionic radii.)

Mg2+(g) and O2−(g)

Chp 10 - Based on the diagram above, which of the following best helps to explain why MgO(s) is not able to conduct electricity, but MgO(l) is a good conductor of electricity?

MgO(s) consists of separate Mg2+ ions and O2− ions held in a fixed lattice, but in MgO(l) the ions are free to move and conduct electricity.

ch-4:Which of the following is the correct net ionic equation of the reaction that occurs when aqueous solutions of ammonia and hydrochloric acid are combined?

NH3(aq)+H+(aq)→NH4+(aq)

Ch8 - Bonding : Which of the following compounds contains both ionic and covalent bonds?

NH4Cl

CH8 - Based on the data in the tables above, which of the following statements provides the best prediction for the boiling point of NaCl ?

NaCl will have a lower boiling point than NaF because the coulombic attractions are weaker in NaCl than in NaF

Chp 10 - Based on the data in the tables above, which of the following statements provides the best prediction for the boiling point of NaCl?

NaCl will have a lower boiling point than NaF because the coulombic attractions are weaker in NaCl than in NaF.

Chp 10 - Which of the following could be the identity of a white crystalline solid that exhibits the following properties? - It melts at 320°C. - It does not conduct electricity as a solid. - It conducts electricity in an aqueous solution.

NaOH(s)

CH8 - Of the following single bonds, which is the LEAST polar?

O-F

CH8 - Resonance is most commonly used to describe the bonding in molecules of which of the following?

O3

CH8 - Which of the following molecules has an angular (bent) geometry that is commonly represented as a resonance hybrid of two or more electron-dot structures?

OF2

ch-4:A chemistry teacher carried out several demonstrations, and students recorded their observations. For one of the demonstrations, a student concluded that a physical change took place, but not a chemical change. Which of the following observations could the student have made of the results of the demonstration?

One piece of solid substance was changed into small pieces.

Chp 10 - Based on the information in the table above, which of the compounds has the highest boiling point, and why?

Propanoic acid, because it can form intermolecular hydrogen bonds

Chp 10 - Based on Coulomb's law and the information in the table above, which of the following anions is most likely to have the strongest interactions with nearby water molecules in an aqueous solution?

S2-

Ch8 - Bonding Which of the following can be inferred from the diagram above that shows the dependence of potential energy on the internuclear distance between two atoms?

The atoms form a bond with a bond length of 75pm.

CH8 - The potential energy of a system of two atoms as a function of their internuclear distance is shown in the diagram above. Which of the following is true regarding the forces between the atoms when their internuclear distance is x?

The attractive and repulsive forces are balanced, so the atoms will maintain an average internuclear distance x.

Ch 5 Gas Laws: A rigid metal tank contains oxygen gas. Which of the following applies to the gas in the tank when additional oxygen is added at constant temperature?

The average speed of the gas molecules remains the same.

Chp 10 - Nonane and 2,3,4-trifluoropentane have almost identical molar masses, but nonane has a significantly higher boiling point. Which of the following statements best helps explain this observation?

The carbon chains are longer in nonane than they are in 2,3,4-trifluoropentane.

Ch8 - The table above shows the melting points of MgO(s) and NaF(s). Which of the following best helps explain why the melting point of MgO(s) is much higher than that of NaF(s) ?

The charges of Mg2+ and O2− ions are greater than those of Na+ and F− ions.

Ch 5 Gas Laws: Diagram 1 above shows equimolar samples of two gases inside a container fitted with a removable barrier placed so that each gas occupies the same volume. The barrier is carefully removed as the temperature is held constant. Diagram 2 above shows the gases soon after the barrier is removed. Which statement describes the changes to the initial pressure of each gas and the final partial pressure of each gas in the mixture and also indicates the final total pressure?

The partial pressure of each gas in the mixture is half its initial pressure; the final total pressure is half the sum of the initial pressures of the two gases.

ch-4:A student combines a solution of NaCl(aq) with a solution of AgNO3(aq) and a precipitate forms. Which of the following is evidence that ionic bonds formed during the precipitation?

The precipitate has a high melting point.

Ch 5 Gas Laws:The reaction between NO(g) and O2(g) to produce NO2(g) in a rigid reaction vessel is represented in the diagram above. The pressure inside the container is recorded using a pressure gauge. Which of the following statements correctly predicts the change in pressure as the reaction goes to completion at constant temperature, and provides the correct explanation?

The pressure will decrease because there are fewer molecules of product than of reactants.

ch-4:A student was given two clear liquids; a colorless liquid and a dark-blue liquid. The student was asked to combine the liquids in a beaker and record observations. Which of the following results, if true, would provide the best evidence that a chemical change took place when the liquids were combined?

The resulting mixture was cloudy.

Chp 10 - Four different liquid compounds in flasks at 20°C are represented above. The table below identifies the compounds. Flask C shows the most particles in the vapor phase. Which of the following is not shown in the model but best helps to explain why flask C must contain pentane?

The strength of the intermolecular forces between the particles in the liquids

ch-4: K2SO3(aq)+2HNO3(aq)→2KNO3(aq)+SO2(g)+H2O(l) When 100.0mL of 0.100MK2SO3(aq) is mixed with 100.0mL of 0.200MHNO3(aq) at 30°C and 1 atm, the volume of SO2 gas produced is 0.24 L. If it is assumed that the reaction goes to completion, which of the following changes would double the volume of SO2 produced at the same temperature and pressure, and why? (For each change, assume that the other solutions and volumes remain the same.)

Using 200.0mL of 0.100MK2SO3(aq) and 200.0mL of 0.200MHNO3(aq) , because this provides double the number of moles with the correct stoichiometric ratio

ch-4: In the reaction between C5H5N(aq) and HCl(aq) represented above, C5H5N acts as

a Brønsted-Lowry base

Chp 10 - A certain crystalline substance that has a low melting point does not conduct electricity in solution or when melted. This substance is likely to be

a molecular solid

Ch 5 Gas Laws: The average kinetic energy of the gas molecules is

all same

Ch 5 Gas Laws: Of the following, the best explanation for the fact that most gases are easily compressed is that the molecules in a gas

are relatively far apart

Ch 5 Gas Laws: At standard temperature and pressure, a 0.50 mol sample of H2 gas and a separate 1.0 mol sample of O2 gas have the same

average molecular kinetic energy