5 Steps to a 5 AP Chemistry 2019

312 ❯ STEP 5. Build Your Test-Taking Confidence

1. What type of reaction generated the nitrogen gas?
   (A) Oxidation-reduction
   (B) Combination
   (C) Decomposition
   (D) Combustion


2. Why must the liquid in the flask be dilute acid?
   (A) Dilute acid is necessary to neutralize the
   sodium hydroxide formed.
   (B) Dilute acid removes ammonia from the gas
   leaving the nitrogen behind.
   (C) Dilute acid causes the reaction to go to
   completion.
   (D) Dilute acid is easier to handle than many
   other liquids.


3. What is the partial pressure of the hydrogen gas
   in the flask?
   (A) 775.2 torr
   (B) 748.2 torr
   (C) 760.0 torr
   (D) 721.2 torr


4. After the system returned to room temperature
   an adjustment was made by raising the beaker
   until the liquid level in both the beaker and the
   flask were the same. Why was this step necessary?
   (A) To remove excess water from the rubber
   tubing and into the beaker
   (B) To equilibrate the pressure in the flask with
   the external pressure
   (C) To make sure all of the hydrogen gas was
   out of the rubber tubing
   (D) To make sure there was no contamination
   by the hydrochloric acid


5. Approximately, how many moles of nitrogen gas
   formed?
   (A) 0.1 mole
   (B) 0.02 mole
   (C) 0.005 mole
   (D) 0.01 mole


6. If the sample were pure sodium azide, approximately
   how many moles of nitrogen gas would form?
   (A) 0.04 mole
   (B) 0.002 mole
   (C) 0.02 mole
   (D) 0.2 mole
   7. Would it be possible to use this experimental
   setup to study a reaction that produced gaseous
   sulfur dioxide, SO 2? If not, why?
   (A) No, because some of the sulfur dioxide gas
   would dissolve in the acid.
   (B) No, because sulfur dioxide reacts with acids
   to produce solid sulfur.
   (C) No, because sulfur dioxide is only a gas at
   very high temperatures.
   (D) Yes, this apparatus could be used.

HCC l D

C

Cl

Cl

Cl C H

Cl

Cl

C

HH

H

HO H

H

C

B

A

O

K+

HH

8. Which of the labeled arrows in the diagram
   above represents the strongest intermolecular
   force of the four indicated?
   (A) Arrow A
   (B) Arrow B
   (C) Arrow C
   (D) Arrow D


9. If about 88% of a sample of pure^131 I decays in
   24 days, what is the approximate half-life of^131 I?
   (A) 24 days
   (B) 16 days
   (C) 8 days
   (D) 90 days

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20-Moore_PE01_p307-340.indd 312 31/05/18 1:58 pm