### All AP Chemistry Resources

## Example Questions

### Example Question #1 : Calculating The Equilibrium Concentrations

Consider formation of Nitrogen monoxide: with . If the initial concentration of N2 was 0.085M and O2 was 0.038 M, what is the concentration of nitrogen monoxide at equilibrium?

**Possible Answers:**

1.2 x 10^{-5} M

1.2 x 10^{-6} M

1.1 x 10^{-3} M

1.1 x 10^{-4 }M

3.2 x 10^{-8} M

**Correct answer:**

1.2 x 10^{-5} M

### Example Question #1 : Calculating The Equilibrium Concentrations

Given the ICE table below, what are the signs on the terms that would appear in the “Change” row?

**Possible Answers:**

-x, -x, +x

+x, +4x, -x

+x, +2x, +x

-x, -2x, +x

+x, +x, +x

**Correct answer:**

-x, -2x, +x

Based on the balanced equation, one would use -x, -2x, and +x.

### Example Question #1 : Calculating The Equilibrium Concentrations

Find the equilibrium concentrations for C in the following chemical reaction: A + B -> 2C

K = 9.0 x 10^{-8}

**Possible Answers:**

1.5 x 10^{-4} M

1.1 M

1.2 x 10^{-2} M

0.12 M

3.0 x 10^{-3} M

**Correct answer:**

1.5 x 10^{-4} M

### Example Question #1 : Calculating The Equilibrium Concentrations

What is the equilibrium concentration for A- in the following reaction if the starting concentration of HA is 0.60 M?

**Possible Answers:**

2.3 x 10^{-3} M

1.2 M

3.5 x 10^{-3} M

1.2 x 10^{-5} M

2.3 x 10^{-4} M

**Correct answer:**

3.5 x 10^{-3} M

### Example Question #2 : Calculating The Equilibrium Concentrations

What is the equilibrium concentration for A- in the following reaction if the starting concentration of HA is 0.30 M?

**Possible Answers:**

** **3.9 x 10^{-5} M

1.5 x 10^{-4} M

2.1 M

1.5 x 10^{-3 }M

2.1 x 10^{-3} M

**Correct answer:**

** **3.9 x 10^{-5} M