5 Steps to a 5 AP Chemistry

Choose the type of energy that best relates to
questions 1–4.

(A) free energy

(B) lattice energy

(C) kinetic energy

(D) activation energy

(E) ionization energy

1. 
   

   the minimum energy required to initiate a reaction

   
   


2. 
   

   the minimum energy required for a non-
   spontaneous reaction

   
   


3. 
   

   The average_____is the same for any
   ideal gas at a given temperature.

   
   


4. 
   

   the energy released when the gaseous ions com-
   bine to form an ionic solid

   
   


5. 
   

   Given the following information:

   
   

C(s) +O 2 (g) →CO 2 (g) ΔH=−393.5 kJ

H 2 (g) +(l/2) O 2 (g) →H 2 O(l)

ΔH=−285.8 kJ

C 2 H 2 (g) +(5/2) O 2 (g) →2 CO 2 (g) +H 2 O(l)

ΔH=−1299.8 kJ

find the enthalpy change for:

2 C(s) +H 2 (g) → C 2 H 2 (g)

(A) 454.0 kJ

(B) −227.0 kJ

(C) 0.0 kJ

(D) 227.0 kJ

(E) −454.0 kJ

6. A sample of gallium metal is sealed inside a well-
   insulated, rigid container. The temperature
   inside the container is at the melting point of
   gallium metal. What can be said about the
   energy and the entropy of the system? Assume
   the insulation prevents any energy change with
   the surroundings.

(A) The total energy increases. The total entropy

will increase.

(B) The total energy is constant. The total

entropy is constant.

(C) The total energy is constant. The total

entropy will decrease.

(D) The total energy is constant. The total

entropy will increase.

(E) The total energy decreases. The total entropy

will decrease.

7. When ammonium chloride dissolves in water,
   the temperature drops. Which of the following
   conclusions may be related to this?

(A) The hydration energies of the ions are very

high.

(B) Ammonium chloride produces an ideal solu-

tion in water.

(C) The heat of solution for ammonium chloride

is exothermic.

(D) Ammonium chloride has a low lattice energy.

(E) Ammonium chloride is more soluble in hot

water.

8. Choose the reaction expected to have the greatest
   increase in entropy.

(A) H 2 O(g) →H 2 O(1)

(B) C(s) +O 2 (g) → CO 2 (g)

(C) Ca(s) +H 2 (g) →CaH 2 (s)

(D) N 2 (g) +3H 2 (g) → 2 NH 3 (g)

(E) 2 KClO 3 (s) →2 KCl(s) +3 O 2 (g)

132  Step 4. Review the Knowledge You Need to Score High

 Review Questions

Answer the following questions. You have 20 minutes. You may not use a calculator. You may

use the periodic table at the back of the book.