Chemistry 1412: Concept Questions

Consider these three changes in the possible distributions of six gaseous particles within three interconnected boxes. Which change has a positive ΔS?

(A)

Which of the protons shown in red is more acidic?

(A) is more acidic

Closely examine Figure 18.4. Which image best represents the amount of O H− added to the buffer in part (b) of the figure?

A.

Which molecule exhibits optical isomerism?

B

Consider the three generic weak acids H A, H B, and H C. The images shown here represent the ionization of each acid at room temperature. Which acid has the largest K a?

B. HB

For a particular reaction in which A → products, a doubling of the concentration of A causes the reaction rate to double. What is the order of the reaction? a. 0 b. 1 c. 2

B: 1

Which halogen has the highest boiling point? a. Cl 2 b. Br 2 c. I 2

C: I2

Consider the reaction A (g) f B (g). The images shown illustrate equilibrium mixtures of A (red) and B (black) at three different temperatures. At which temperature is the equilibrium constant the largest?

C: T3

Which structure is an isomer of the molecule shown here (and not just the same structure)?

D

A

Which of the diagrams below best depicts the vapor emitted from a pot of boiling water?

Which solution is most acidic (that is, which one has the lowest pH)? a. 0.10 M HCl b. 0.10 M HF c. 0.20 M HF

a. 0.10 M HCl

Which solution is most acidic (that is, has the lowest pH)? a. 1.0 M HCl b. 2.0 M HF c. A solution that is 1.0 M in HF and 1.0 M in HClO

a. 1.0 M HCl

What is the vapor pressure of a solution in which the mole fraction of the solute is 0.200 and the vapor pressure of the pure solvent is 100.0 torr? (Assume a single nonvolatile, nonelectrolyte solute.) a. 20.0 torr b. 80.0 torr c. 100.0 torr d. 120.0 torr

a. 20.0 torr (0.200 X 100.0=20)

According to Le Châtelier's principle and the dependence of free energy on gaseous reactant and product concentrations, which statement is true? a. A high concentration of reactants relative to products results in a more spontaneous reaction than one in which the reactants and products are in their standard states. b. A high concentration of products relative to reactants results in a more spontaneous reaction than one in which the reactants and products are in their standard states. c. A reaction in which the reactants are in standard states, but in which no products have formed, has a ΔGrxn that is more positive than ΔG°rxn.

a. A high concentration of reactants relative to products results in a more spontaneous reaction than one in which the reactants and products are in their standard states.

If the solvent-solute interactions in a mixture are comparable in strength to the solvent-solvent interactions and the solute-solute interactions, what can you conclude about solution formation in this mixture? a. A homogeneous solution forms. b. A homogeneous solution does not form. c. The formation of a homogeneous solution is uncertain.

a. A homogeneous solution forms.

Two 25.0-milliLiter samples of unknown monoprotic weak acids, A and B, are titrated with 0.100 M NaOH solutions. The titration curve for each acid is shown below. Which of the two weak acid solutions is more concentrated? a. Acid A b. Acid B

a. Acid A

A solution contains equal concentrations of Ba2+, Pb2+, and Ca2+ ions. When potassium sulfate is added to this solution, which cation precipitates first? a. Ba2+ b. Pb2+ c. Ca2+

a. Ba2+

Examine the Henry's law constants in Table 14.4. Why is the constant for ammonia larger than the others? a. Because ammonia is polar and the other substances in the table are nonpolar. b. Because ammonia has the highest molar mass of the substances listed in the table. c. Because ammonia is nonpolar and the other substances in the table are polar.

a. Because ammonia is polar and the other substances in the table are nonpolar.

Based on conceptual reasoning, which of the following best explains why I2 does not oxidize Br−? I2(s) + 2Br-(aq) -> 2I-(aq) + Br2(l) a. Br is more electronegative than I; therefore, you do not expect Br− to give up an electron to I2. b. I is more electronegative than Br; therefore, you do not expect I2 to give up an electron to Br−. c. Br− is in solution and I2 is a solid. Solids do not gain electrons from substances in solution.

a. Br is more electronegative than I; therefore, you do not expect Br− to give up an electron to I2.

Which substance has the highest boiling point? a. CH3OH b. CO c. N2

a. CH3OH

Which of these metals does not act as a sacrificial electrode for iron? a. Cu b. Mg c. Zn d. Mn

a. Cu

In an electrochemical cell, Q = 0.0010 and K = 0.10. What can you conclude about Ecell and E^o cell a. Ecell is positive and E^o cell is positive. b. Ecell is negative and E^o cell is negative. c. Both Ecell and E^o cell are positive. d. Both Ecell and E^o cell are negative.

a. Ecell is positive and E^o cell is positive.

Which acid is stronger? a. HF Ka=6.8x10^-4 b. HClO Ka=2.9x10^-8

a. HF Ka=6.8x10^-4

Under which circumstances are Kp and Kc equal for the reaction shown here? aA(g) + bB(g) f cC(g) + dD(g) a. If a + b = c + d. b. If the reaction is reversible. c. If the equilibrium constant is small.

a. If a + b = c + d.

For the generic reaction, A(g) f B(g), consider each value of K and initial concentration of A. For which set of values does the x is small approximation most likely apply? a. K= 1.0 x 10^-5 ; [A]= 0.250M b. K= 1.0x10^-2; [A]= 0.250 M c. K= 1.0x10^-5; [A]=0.00250M d.K= 1.0x10^-2; [A]=0.00250M

a. K= 1.0 x 10^-5 ; [A]= 0.250M

Arrange these gases in order of increasing standard molar entropy: SO3, Kr, Cl2. a. Kr < Cl2 < SO3 b. Kr < SO3 < Cl2 c. SO3 < Cl2 < Kr d. Cl2 < Kr < SO3

a. Kr < Cl2 < SO3

Which ionic compound forms an acidic solution when dissolved in water? a. NH4Br b. KCl c. NaHCO3

a. NH4Br

Suppose a person ingests equal amounts of two nuclides, both of which are beta emitters (of roughly equal energy). Nuclide A has a half-life of 8.5 hours and Nuclide B has a half-life of 15.0 hours. Both nuclides are eliminated from the body within 24 hours of ingestion. Which of the two nuclides produces the greater radiation dose? a. Nuclide A b. Nuclide B c. Both nuclides produce the same radiation dose.

a. Nuclide A

What level of protein structure is maintained by peptide bonds? a. Primary b. Secondary c. Tertiary d. Quaternary

a. Primary

Reaction A and reaction B have identical frequency factors. However, reaction B has a higher activation energy than reaction A. Which reaction has a greater rate constant at room temperature? a. Reaction A b. Reaction B

a. Reaction A

Which statement best explains why reaction rates generally increase with increasing temperature? a. Reaction rates increase with increasing temperature because, as temperature increases, a greater fraction of molecules have enough thermal energy to surmount the activation barrier. b. Reaction rates increase with increasing temperature because, as temperature increases, the pre-exponential factor of the rate constant increases. c. Reaction rates increase with increasing temperature because, as temperature increases, molecules decompose into their constituent atoms, which can then form new bonds to form the products.

a. Reaction rates increase with increasing temperature because, as temperature increases, a greater fraction of molecules have enough thermal energy to surmount the activation barrier.

A solution contains equal amounts (in moles) of liquid components A and B. The vapor pressure of pure A is 100 mmHg and that of pure B is 200 mmHg. The experimentally measured vapor pressure of the solution is 120 mmHg. What are the relative strengths of the solute-solute, solute-solvent, and solvent-solvent interactions in this solution? a. Solute-solvent interactions > solute-solute and solvent-solvent interactions b. Solute-solvent interactions = solute-solute and solvent-solvent interactions c. Solute-solute and solvent-solvent interactions > solute-solvent interactions

a. Solute-solvent interactions > solute-solute and solvent-solvent interactions

Which statement best captures the difference between volts and amps? a. The volt is a unit that quantifies the difference in electrical potential energy, and the amp is a unit that quantifies the flow of electrical current. b. The amp is a unit that quantifies the difference in electrical potential energy, and the volt is a unit that quantifies the flow of electrical current. c. The volt and amp are two different units used to measure the same thing, the flow of electrical current.

a. The volt is a unit that quantifies the difference in electrical potential energy, and the amp is a unit that quantifies the flow of electrical current.

The H 3 O+ concentrations of three solutions at room temperature are as follows. Which solution is acidic? a. [H3O+]= 1 x 10^-3 M b. [H3O+]= 1 x 10^-7 M c. [H3O+]= 1 x 10^-9M

a. [H3O+]= 1 x 10^-3 M

A buffer contains the weak acid HA and its conjugate base A−. The weak acid has a pKa of 4.82 and the buffer has a pH of 4.25. Which statement is true of the relative concentrations of the weak acid and conjugate base in the buffer? a. [HA] > [A−] b. [HA] < [A−] c. [HA] = [A−]

a. [HA] > [A−]

A 1.0-L buffer solution is 0.10 M in HF and 0.050 M in NaF. Which action destroys the buffer? a. adding 0.050 mole of HCl b. adding 0.050 mole of NaOH c. adding 0.050 mole of NaF d. none of the above

a. adding 0.050 mole of HCl

A nuclide has a mass number of 116. The atomic mass of the element listed in the periodic table is 102.9. Will the element undergo beta decay or positron emission? a. beta decay b. positron emission

a. beta decay

In a voltaic cell, in which direction do electrons flow? a. from higher potential energy to lower potential energy b. from the cathode to the anode c. from lower potential energy to higher potential energy

a. from higher potential energy to lower potential energy

Which statement is true regarding the sublimation of dry ice (solid CO2)? a. ΔH is positive, ΔS is positive, and ΔG is positive at low temperatures and negative at high temperatures. b. ΔH is negative, ΔS is negative, and ΔG is negative at low temperatures and positive at high temperatures. c. ΔH is negative, ΔS is positive, and ΔG is negative at all temperatures. d. ΔH is positive, ΔS is negative, and ΔG is positive at all temperatures.

a. ΔH is positive, ΔS is positive, and ΔG is positive at low temperatures and negative at high temperatures.

A sample initially contains 1.6 moles of a radioactive isotope. How much of the sample remains after four half-lives? a. 0.0 mol b. 0.10 mol c. 0.20 mol d. 0.40 mol

b. 0.10 mol

A first-order reaction (A → B) has a half-life of 25 minutes. If the initial concentration of A is 0.300 M, what is the concentration of B after 50 minutes? (Do not use a calculator to solve this problem.) a. 0.300 M b. 0.225 M c. 0.150 M d. 0.100 M

b. 0.225 M

The reaction A (g) f 2B (g) has an equilibrium constant of K=0.010. What is the equilibrium constant for the reaction B(g) f 1/2 A(g)? a. 1 b. 10 c. 100 d. 0.0010

b. 10

If you combine 25.0 grams of a solute that has a mass of 25.0 grams/moles with 100.0 g of a solvent, what is the molality of the resulting solution? a. 0.25 m b. 10.0 m c. 1.0 m d. 8.0 m

b. 10.0 m

Consider this graph representing the decay of a radioactive nuclide. What is the half-life of the nuclide? a. 625 years b. 1250 years c. 2500 years d. 3125 years

b. 1250 years

A buffer contains equal amounts of a weak acid and its conjugate base and has a pH of 5.25. Which would be a reasonable value of buffer pH after the addition of a small amount of acid? a. 4.15 b. 5.15 c. 5.35 d. 6.35

b. 5.15

Two 25.0-milliLiter samples of unknown monoprotic weak acids, A and B, are titrated with 0.100 M NaOH solutions. The titration curve for each acid is shown below. Which of the two weak acids has the larger Ka? a. Acid A b. Acid B

b. Acid B

An electrode has a negative electrode potential. Which statement is correct regarding the potential energy of an electron at this electrode? a. An electron at this electrode has a lower potential energy than it has at a standard hydrogen electrode. b. An electron at this electrode has a higher potential energy than it has at a standard hydrogen electrode. c. An electron at this electrode has the same potential energy as it has at a standard hydrogen electrode.

b. An electron at this electrode has a higher potential energy than it has at a standard hydrogen electrode.

By absorbing energy from their surroundings and synthesizing large, complex biological molecules, plants and animals tend to concentrate energy, not disperse it. How can this happen? a. Biological systems only appear to concentrate energy. In reality, large, complex biological molecules have more entropy than the substances from which they are composed. b. Biological systems can decrease their own entropy by creating more entropy in their surroundings. c. Biological systems are an exception to the second law of thermodynamics.

b. Biological systems can decrease their own entropy by creating more entropy in their surroundings.

Which statement is true for both electrolytic and voltaic cells? a. The cell spontaneously produces a positive voltage. b. Electrons flow from the anode to the cathode. c. Oxidation occurs at the cathode.

b. Electrons flow from the anode to the cathode.

For which reaction does Kp = Kc? a. 2Na2O2(s) + 2CO2(g) f 2Na2CO3(s) + O(g) b. Fe2O3(s) + 3CO(g) f 2Fe(s)+ 3CO2(g) c. NH4NO3(s) f N2O(g) + 2H2O(g)

b. Fe2O3(s) + 3CO(g) f 2Fe(s)+ 3CO2(g)

Which pair is not a conjugate acid-base pair? a. (CH3)3N; (CH3)3NH+ b. H2SO4; H2SO3 c. HNO2; NO2−

b. H2SO4; H2SO3

Solution A is a 1.0 m solution with a nonionic solute and water as the solvent. Solution B is a 1.0 m solution with the same nonionic solute and ethanol as the solvent. Which solution has the greater increase in its boiling point (relative to the pure solvent)? a. Solution A b. Solution B

b. Solution B

A solution is saturated in both nitrogen gas and potassium bromide at 75 °C. When the solution is cooled to room temperature, what is most likely to happen? a. Some nitrogen gas bubbles out of solution. b. Some potassium bromide precipitates out of solution. c. Some nitrogen gas bubbles out of solution, and some potassium bromide precipitates out of solution. d. Nothing happens.

b. Some potassium bromide precipitates out of solution.

As the p H of a solution increases (gets higher), what happens to the acidity of the solution? a. The acidity increases. b. The acidity decreases. c. The acidity remains constant.

b. The acidity decreases.

The equilibrium constant for the reaction A (g) f B(g) is 10. A reaction mixture initially contains [A] = 1.1 M and [B] = 0.0 M. Which statement is true at equilibrium? a. The reaction mixture contains [A] = 1.0 M and [B] = 0.1 M. b. The reaction mixture contains [A] = 0.1 M and [B] = 1.0 M. c. The reaction mixture contains equal concentrations of A and B.

b. The reaction mixture contains [A] = 0.1 M and [B] = 1.0 M.

A substance has a triple point at −24.5 °C and 225 mmHg. What is most likely to happen to a solid sample of the substance as it is warmed from −35 °C to 0 °C at a pressure of 220 mmHg? a. The solid melts into a liquid. b. The solid sublimes into a gas. c. Nothing (the solid remains solid).

b. The solid sublimes into a gas

Californium-252 is bombarded with a boron-10 nucleus to produce another nuclide and six neutrons. Which nuclide forms? a. lawrencium-262 b. lawrencium-256 c. californium-246 d. neptunium-236

b. lawrencium-256

A process will be spontaneous when ΔG is: a. positive b. negative

b. negative

The heat capacity of ice is Cs, ice = 2.09 Joule/(gram °Celsius) and the heat of fusion of ice is 6.02 kJ/moles. When a small ice cube at −10 °Celsius is put into a cup of water at room temperature, which of the following plays a greater role in cooling the liquid water: the warming of the ice from −10 °Celsius to 0 °Celsius, or the melting of the ice? a. the warming of the ice from −10 °Celsius to 0 °Celsius b. the melting of the ice

b. the melting of the ice

Which type of lipid is most common in our diet? a. phospholipids b. triglycerides c. glycolipids d. steroids

b. triglycerides

A reaction is spontaneous under a certain set of conditions. What can you conclude about ΔGrxn and Q? a. ΔGrxn < 0, Q > K b. ΔGrxn < 0, Q < K c. ΔGrxn > 0, Q < K d. ΔGrxn > 0, Q > K

b. ΔGrxn < 0, Q < K

Which weak acid solution has the greatest percent ionization? a. 0.100 M HC2H3O2 b. 0.500 M HC2H3O2 c. 0.0100 M HC2H3O2

c. 0.0100 M HC2H3O2

Which aqueous solution has the highest boiling point? a. 0.50 M C12H22O11 b. 0.50 M NaCl c. 0.50 M MgCl2

c. 0.50 M MgCl2

Assuming you have four different bases, how many amino acids can you code for with two-base sequences? a. 2 b. 4 c. 16 d. 64

c. 16

An ancient bone contains 1/8 of the amount of carbon-14 found in living organisms. How old is the bone? a. 5,715 years (one C-14 half-life) b. 11,430 years (two C-14 half-lives) c. 17,145 years (three C-14 half-lives) d. 22,860 years (four C-14 half-lives)

c. 17,145 years (three C-14 half-lives)

For the reaction, A(g) f 2B(g), Kc=4.0. A reaction mixture at equilibrium contains [A] = 1.0 M. What is the concentration of B in the reaction mixture? a. 0.50 M b. 1.0 M c. 2.0 M d. 4.0 M

c. 2.0 M

Silver plating uses the reaction Ag+ (aq) + e- -> Ag(s) How many moles of electrons must pass through an electrolytic cell for silver plating in order to plate 3 moles of Ag? a. 1 mole e− b. 2 mole e− c. 3 mole e− d. 4 mole e−

c. 3 mole e−

What is the pH at the half-equivalence point in the titration of a weak base with a strong acid? The pKb of the weak base is 8.75. a. 8.75 b. 7.0 c. 5.25 d. 4.37

c. 5.25 (14-8.75=5.25)

How many different tripeptides can form from the three amino acids listed here? Ser, Ala, Gly a. 1 b. 3 c. 6 d. 12

c. 6

A decomposition reaction, with a rate that is observed to slow down as the reaction proceeds, has a half-life that depends on the initial concentration of the reactant. Which statement is most likely true for this reaction? a. A plot of the natural log of the concentration of the reactant as a function of time is linear. b. The half-life of the reaction increases as the initial concentration increases. c. A doubling of the initial concentration of the reactant results in a quadrupling of the rate.

c. A doubling of the initial concentration of the reactant results in a quadrupling of the rate.

Which metal dissolves in HNO3 but not in HCl? a. Fe b. Au c. Ag

c. Ag

Consider these 3 titrations: 1) the titration of 25.0 mL of a 0.100 M monoprotic weak acid with 0.100 M NaOH 2) the titration of 25.0 mL of a 0.100 M diprotic weak acid with 0.100 M NaOH 3)the titration of 25.0 mL of a 0.100 M strong acid with 0.100 M NaOH Which statement is most likely to be true? a. All three titrations have the same initial pH. b. All three titrations have the same pH at their first equivalence points. c. All three titrations require the same volume of NaOH to reach their first equivalence points.

c. All three titrations require the same volume of NaOH to reach their first equivalence points.

Consider the table listing the solubilities of several alcohols in water and in hexane. Which statement best describes the observed trend in terms of intermolecular forces? a. As you move down the list, molecules become more polar, less soluble in water, and more soluble in hexane. b. As you move down the list, molecules become more polar, more soluble in water, and less soluble in hexane. c. As you move down the list, molecules become less polar, less soluble in water, and more soluble in hexane. d. As you move down the list, molecules become less polar, more soluble in water, and less soluble in hexane.

c. As you move down the list, molecules become less polar, less soluble in water, and more soluble in hexane.

The formulas of three noncyclic hydrocarbons are listed below. Which of these is an alkene? a. C4H10 b. C3H4 c. C5H10

c. C5H10

A redox reaction has an equilibrium constant of K= 1.2 x 10^3. Which statement is true regarding ΔGrxn and Ecell for this reaction? a. Ecell is positive and ΔGrxn is positive. b. Ecell is negative and ΔGrxn is negative. c. Ecell is positive and ΔGrxn is negative d. Ecell is negative and ΔGrxn is positive.

c. Ecell is positive and ΔGrxn is negative

Which anion acts as a weak base? a. Cl− b. Br− c. F−

c. F−

Which reaction do you expect to have the smallest orientation factor? a. H(g) + I(g) -> HI(g) b. H2(g) + I2 (g) -> 2HI (g) c. HCl (g) + HCl (g) -> H2 (g) = Cl2 (g)

c. HCl (g) + HCl (g) -> H2 (g) = Cl2 (g)

Which compound, when added to water, is most likely to increase the solubility of CuS? a. NaCl b. KNO3 c. NaCN d. MgBr2

c. NaCN

For the reaction N2O4(g) f 2NO2(g) , a reaction mixture at a certain temperature initially contains both N2O4 and NO2 in their standard states, hence, PN2O4 = 1 atm and PNO2 = 1 atm. If Kp = 0.15, which statement is true of the reaction mixture before any reaction occurs? a. Q = K; the reaction is at equilibrium. b. Q < K; the reaction will proceed to the right. c. Q > K; the reaction will proceed to the left.

c. Q > K; the reaction will proceed to the left.

Which statement does NOT generally apply to a chemical reaction in dynamic equilibrium? a. The rates of the forward and reverse reactions are equal. b. The concentrations of the reactants and products are constant. c. The concentrations of the reactants and products are equal.

c. The concentrations of the reactants and products are equal.

Which process undergoes a decrease in entropy for water? a. The melting of ice in a glass b. The boiling of water in a saucepan c. The condensation of water on the sides of a cold glass

c. The condensation of water on the sides of a cold glass

Which process is inconsistent with the second law of thermodynamics? a. The spontaneous creation of energy from nothing. b. The spontaneous creation of matter from nothing. c. The spontaneous concentration of energy from dispersed energy.

c. The spontaneous concentration of energy from dispersed energy.

What happens to the vapor pressure of a substance when its surface area is increased at constant temperature? a. The vapor pressure increases. b. The vapor pressure remains the same. c. The vapor pressure decreases.

c. The vapor pressure decreases.

In which solution is BaSO4 most soluble? a. a solution that is 0.10 M in BaNO3 b. a solution that is 0.10 M in Na2SO4 c. a solution that is 0.10 M in NaNO3

c. a solution that is 0.10 M in NaNO3

If the room next door contains an alpha emitter, a beta emitter, and a gamma emitter, all with similar activities, which particles are you most likely to detect in the room you are in? a. alpha particles b. beta particles c. gamma rays

c. gamma rays

Which state of matter is compressible? a. solid b. liquid c. gas

c. gas

Which property is not associated with an acid? a. dissolves metals b. turns blue litmus red c. has a bitter taste

c. has a bitter taste

Arrange the compounds from least oxidized to most Oxidized. a. iii < i < iv < ii b. ii < i < iv < iii c. iii < iv < i < ii b. ii < iv < i < iii

c. iii < iv < i < ii

The initial concentration and Ka of several weak acid (HA) solutions are listed. For which solution is the x is small approximation least likely to work in finding the pH? a. [HA]=0.100 M Ka=1.0x10^-5 b. [HA]= 1.00M Ka=1.0x10^-6 c. [HA]= 0.0100M Ka=1.0x10^-3 d. [HA]=1.0 M Ka=1.0x10^-3

c. initial [HA] = 0.0100 M Ka= 1.0 x 10^-3

Consider the graphical representation of a series of decays shown to the right. The arrow labeled x and the arrow labeled y each correspond to what kind of decay? a. x corresponds to alpha decay and y corresponds to positron emission. b. x corresponds to positron emission and y corresponds to alpha decay. c. x corresponds to alpha decay and y corresponds to beta decay. d. x corresponds to beta decay and y corresponds to alpha decay.

c. x corresponds to alpha decay and y corresponds to beta decay.

For the reaction A + 2B → C under a given set of conditions, the initial rate is 0.100 M/s. What is (delta [B])/(delta t) under the same conditions? a. −0.0500 M/s b. −0.100 M/s c. −0.200 M/s d. +0.200 M/s

c. −0.200 M/s

The reaction A(g) f B(g) has an equilibrium constant that is less than one. What can you conclude about ΔG°rxn for the reaction? a. ΔG°rxn = 0 b.ΔG°rxn < 0 c.ΔG°rxn > 0

c.ΔG°rxn > 0

The reaction A → B has been experimentally determined to be second order. The initial rate is 0.0100 M/s at an initial concentration of A of 0.100 M. What is the initial rate at [A] = 0.500 M ? a. 0.00200 M/s b. 0.0100 M/s c. 0.0500 M/s d. 0.250 M/s

d. 0.250 M/s

How many protons and neutrons are there in the isotope ^27 13 Al? a. 27 neutrons; 13 protons b. 13 neutrons; 27 protons c. 13 neutrons; 14 protons d. 14 neutrons; 13 protons

d. 14 neutrons; 13 protons

Which sample of water has the greatest rate of vaporization? a. A 100 mL sample of water at 25 °Celsius in 100- mL beaker with a 5 centimetre diameter. b. A 100 mL sample of water at 55 °Celsius in 100- mL beaker with a 5 centimetre diameter. c. A 100 mL sample of water at 25 °Celsius in 250- mL beaker with a 7 centimetre diameter. d. A 100 mL sample of water at 55 °Celsius in 250- mL beaker with a 7 centimetre diameter.

d. A 100 mL sample of water at 55 °Celsius in 250- mL beaker with a 7 centimetre diameter.

The amount of strong acid in the flask shown here is to be titrated by a strong base. Which mark on the burette next to the flask indicates the amount of base required to reach the equivalence point? a. A b. B c. C d. D

d. D

A solution contains both NaI and NaBr. Which oxidizing agent could you add to the solution to selectively oxidize I−(aq) but not Br−(aq)? a. Cl2 b. H2O2 c. CuCl2 d. HNO3

d. HNO3

Which statement is true? a. Ideal gases mix because mixing decreases their potential energy. b. Ideal gases mix because mixing increases their potential energy. c. Ideal gases mix because mixing decreases their entropy. d. Ideal gases mix because mixing increases their entropy.

d. Ideal gases mix because mixing increases their entropy.

According to the law of mass action, what is the correct expression for the equilibrium constant for the below reaction? 2A + B f 3C a. K= [C]/ [A][B] b. K= 3[C] / 2[A][B] c. K= [A]2[B]/ [C]3 d. K= [C]3/[A]2[B]

d. K= [C]3/[A]2[B]

Consider the exothermic reaction: 2NO(g)+ CL2(g) f 2NOCl(g) Which change causes a reaction mixture at equilibrium to shift right? a. Adding N O C l to the reaction mixture. b. Increasing the volume of the reaction vessel at constant temperature. c. Increasing the temperature of the reaction vessel. d. None of the above.

d. None of the above.

What is the rate law for the elementary step Cl+CO -> ClCO? a. Rate = k[Cl] b. Rate = k[CO] c. Rate = k[ClCO] d. Rate = k[Cl][CO]

d. Rate = k[Cl][CO]

Which solution is a buffer? a. a solution that is 0.100 M in HNO2 and 0.100 M in HCl b. a solution that is 0.100 M in HNO3 and 0.100 M in NaNO3 c. a solution that is 0.100 M in HNO2 and 0.100 M in NaCl d. a solution that is 0.100 M in HNO2 and 0.100 M in NaNO2

d. a solution that is 0.100 M in HNO2 and 0.100 M in NaNO2

Which type of carbohydrate functions as the main structural material in plants? a. glucose b. glycogen c. sucrose d. cellulose

d. cellulose