5 Steps to a 5 AP Chemistry 2019

348 ❯ STEP 5. Build Your Test-Taking Confidence

26. Choose the energy profile that best describes this
    mechanism.
    (A)

E

Reaction progress

(B)

E

Reaction progress

(C)

E

Reaction progress

(D)

E

Reaction progress

27. What is the rate law for the reaction?
    (A) Rate = k[N 2 O 5 ]^2
    (B) k = [N 2 O 5 ]
    (C) Rate = k[N 2 O 5 ]

(D) k =

[][]

[]

2

4

2

25

2

NO O

NO

Use the information on the containers in the

following diagram to answer questions 28–30.

A

He

298 K

0.5 mole

10.0 L

B

Ne

298 K

0.5 mole

10.0 L

C

Ar

298 K

0.5 mole

10.0 L

D

Kr

298 K

0.5 mole

10.0 L

Approximate molar masses:

He = 4 g mol-^1 , Ne = 20 g mol-^1 ,

Ar = 40 g mol-^1 , Kr = 84 g mol-^1

28. If a sample of Kr effuses at a rate of 35 mL per
    second at 298 K, which of the gases below will
    effuse at approximately double the rate under the
    same conditions?
    (A) Ar
    (B) He
    (C) Ne
    (D) Impossible to determine


29. Assuming all four gases are behaving ideally,
    which of the following is the same for all the gas
    samples?
    (A) Average kinetic energy of the atoms
    (B) Average speed of the atoms
    (C) Density of the gas in the container
    (D) All properties are the same for gases behav-
    ing ideally


30. Which of the gases will show the greatest devia-
    tion from ideal behavior?
    (A) He
    (B) Ne
    (C) Ar
    (D) Kr

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