Assignment

Question 1

The initial rates for a reaction A and B were studied using the following initial concentrations in mol/L.
Expt 1. [A]=0.300, [B]=0.400, rate=2.80x10^-4 M/s
Expt 2. [A]=1.04, [B]=0.400, rate=2.80x10^-4 M/s
Expt 3. [A]=0.695, [B]=1.63, rate=4.65x10^-3 M/s
What is the order of reaction with respect to B?

a. 1

b. 0

c. insufficient information

d. 2

Question 2

Suppose the rate law for a reaction is

rate = k[X]¹[Y]²

and the rate of the reaction is 0.820 M/min when [X] = 0.697 M. All other factors being equal, if [X] = 1.96 M, the rate of the reaction would be

a. 2.54 M/min

b. 2.31 M/min

Question 3

The concentration of reactant A was monitored over time and the following data were obtained:

t=0, [A]=4.53x10^-3 M
t=292 s, [A]=2.26x10^-3 M
t=584 s, [A]=1.13x10^-3 M
Which of the following rate laws is consistent with the data?

a. rate = (7.56x10^-1 M^-1 s^-1) [A]²

b. rate = (2.37x10^-3 s^-1) [A]

c. rate = (7.56x10^-1 s^-1) [A]

d. rate = (2.37x10^-3 M^-1 s^-1) [A]²

Question 4

The internuclear distance between atoms "A" and "B" in diatomic molecule AB is 1.36 Angstrom. If the molecule has a dipole moment of 3.23 Debye, calculate the percent ionic character.

a. 56.8%

b. 55.7%

c. 49.4%

Question 5

In the following question, treat bonds between atoms with electronegativity difference less than 0.5 (on the Pauling scale) as nonpolar.

The molecule H₂S

a. has no polar bonds and is nonpolar

b. has no polar bonds but is polar

c. has polar bonds and is polar

d. has polar bonds but is nonpolar

Question 6

What type of intermolecular forces is due to induced (temporary) dipole moments in molecules?

a. Hydrogen bonding

b. London dispersion forces

c. Dipole-dipole interaction

Question 7

The structure of BeF₂ can be considered as of the type AX_mE_n, where one central atom (A) is surrounded by m terminal atoms (X) and has n lone pairs. In this particular case, the central atom
a...

a. has an octet (which includes two lone pairs)

b. has an octet (which includes one lone pair)

c. has less than an octet (two pairs short)

d. has an octet with no lone pair

e. has less than an octet (one pair short)

Question 8

Which of the following are resonance structures?

a. I and II only

b. I and III only

c. I, II, and III

d. II and III only

Question 9

A pure sample of liquid X has a normal boiling point of 63.5^oC and a boiling point elevation constant of 4.93 ^oC mol^-1 kg. When liquid X is mixed with nonvolatile solute particles, the boiling point of the resulting mixture was found to be 68.9^oC. Calculate the molality of solute particles in the solution.

a. 1.04 mol/kg

b. 1.10 mol/kg

c. 14.0 mol/kg

d. 12.9 mol/kg

Question 10

A solution is prepared by mixing 37.2 mL of 0.389 M potassium phosphate(aq) and 43.0 mL of 0.490 M potassium sulfate(aq), then adding enough water to bring the total volume to 200.0 mL. Calculate the molarity of K⁺ in the resulting solution.

a. 4.28x10^-1 M

b. 3.64x10^-1 M

c. 2.75 M

d. 2.34 M

Question 11

A pure sample of liquid X has a normal freezing point of 11.9^oC and a freezing point depression constant of 5.24 ^oC mol^-1 kg. When 575 g of liquid X is mixed with 0.650 mol nonvolatile solute particles, the freezing point of the resulting mixture will be...

a. 18.7 ^oC

b. 5.98 ^oC

c. 17.8 ^oC

d. 5.68 ^oC

Question 12

What is the molar concentration of sodium ions in a 0.330M NaNO₃(aq) solution?

a. 2.89 M Na⁺

b. 3.03 M Na⁺

c. 0.330 M Na⁺

d. 3.46x10^-1 M Na⁺

Question 13

Which of the following salts yields an acidic solution in water?

a. LiF

b. AlCl₃

c. NaNO₃

d. NaI

e. KBr

Question 14

An insoluble salt made up of M²⁺ and X^- ions has a Ksp of 8.50x10^-11. Calculate the solubility.

a. 1.33x10^-3 mol/L

b. 6.39x10^-3 mol/L

c. 2.77x10^-4 mol/L

d. 9.22x10^-6 mol/L

Question 15

Which of the following is the conjugate acid of HCO₃^-?

a. H₃CO₃⁺

b. CO₃^2-

c. HCO₃^2-

d. H₂CO₃

e. HCO₃^-

Question 16

The pH of a 9.05x10^-2 M solution of B(aq) is 11.706. Calculate the Kb.

a. 3.02x10^-4

b. 2.85x10^-4

c. 2.57x10^-4

Question 17

Which of the following is a possible pH of a 2.99x10^-3 M solution of B(aq) if B is a weak base?

a. 11.476

b. 9.257

c. 2.524

Question 18

Predict if a precipitate of M₂X would be formed in a solution that is 2.00x10^-5M in M⁺ and 3.53x10³M in X^2-. The Ksp of M₂X is 1.66x10^-6.

a. No, a precipitate will not be formed.

b. Yes, a precipitate will be formed.

Question 19

Which of the following describes the effect of removing products from a reaction mixture at equilibrium? (Q is the reaction quotient, Keq is the equilibrium constant)

a. increase in Q; reaction shifts to the right until Q=Keq again

b. change in Keq; reaction shifts to the left or right until Q=Keq again

c. decrease in Q; reaction shifts to the right until Q=Keq again

d. increase in Q; reaction shifts to the left until Q=Keq again

e. decrease in Q; reaction shifts to the left until Q=Keq again

Question 20

Consider the reaction: A(g) + B(g) = 2C(g), K_c = 30.0.

Suppose an 4.70-L mixture initially contains 3.56x10^-3 mol A, 3.56x10^-3 mol B, and no C. Calculate the equilibrium concentration of
a.

a. 2.13x10^-4 mol/L

b. 1.11x10^-3 mol/L

c. 2.03x10^-4 mol/L

Question 21

How are the equilibrium constants Kp and Kc related for the following reaction:

2 NO₂(g) → 2 NO(g) + O₂(g)

a. Kc = (Kp)(RT)²

b. Kp = Kc

c. Kc = (Kp)(RT)

d. Kp = (Kc)(RT)

e. Kp = (Kc)(RT)²

Question 22

Consider the following fictitious reaction at equilibrium:

A(g) + B(g) ↔ C(g) ΔH = -80 kJ

Which of the following stresses would shift the equilibrium to the left?

a. decreasing the volume by increasing the pressure at constant temperature

b. adding more A

c. adding more C

d. decreasing the temperature

e. adding a catalyst

Question 23

Given the following standard reduction potentials:

Cu|Cu²⁺, 0.34 V
Ag|Ag⁺, 0.80 V
Based on the given information, under standard conditions, True or False:
Cu²⁺ is a better reducing agent than Ag⁺.

a. False

b. True

Question 24

State whether O is oxidized or reduced in

nitric oxide → nitrogen dioxide

a. neither

b. oxidized

c. reduced