What is the pH of a solution that has a hydrogen ion concentration of [0.001]?

A. 1
Incorrect. Check your calculation; you should use pH= -log (0.001).

B. 2
Incorrect. Check your calculation; you should use pH= -log (0.001).

C. 3
Correct!

D. 11
Incorrect. Check your calculation; you should use pH= -log (0.001).

A truck carrying concentrated nitric acid overturns and spills its contents. The acid drains into a nearby pond. The pH of the pond water was 8.0 before the spill. After the spill, the pond water contains 1,000 times more H⁺ ions. What is the new pH of the pond after the spill?

A. 11.0
Incorrect. Eleven would be 1000 times more basic.

B. The pH did not change.
Incorrect. pH is a measure of the acidity, therefore the pH will change.

C. 5.0
Correct!

D. 7
Incorrect. Seven would be10 times more acidic.

A water sample has a pH of 9 at 25°. What is the hydroxide concentration in the water sample?

A. 3 × 10^-9
Incorrect. This is the hydronium ion concentration.

B. 1 × 10^-5
Correct!

C. 1 × 10^-14
Incorrect. This is the Kw of water.

D. 1 × 10^-7
Incorrect. This solution will have a pH of 7.

What is the pH of a solution of LiOH with a hydroxide concentration of [OH^-] = 1×10^-5?

A. -5
Incorrect. Use -log(1×10^-5) to find pOH, then subtract from 14 to find pH.

B. 5
Incorrect. Use -log(1×10^-5) to find pOH, then subtract from 14 to find pH.

C. 9
Correct!

D. -9
Incorrect. Use -log(1×10^-5) to find pOH, then subtract from 14 to find pH.