The concentration of hydroxide ions in a solution is approximately What is the pH of the solution?
A. 4
B. -4
C. 10
D.
C
The concentration of the hydroxide ions is given. With such a large concentration of hydroxide ions, it is logical to assume that the solution is basic and that the pH should therefore be greater than 7. This line of reasoning implies that the correct answer must be C. The direct calculation is given below.