Which of the following could be the concentration of hydronium ions in an acidic solution?
A.
B.
C.
D.
A
Choices B and C have pH's greater than 7. Since concentrations cannot be negative, choice D must be eliminated as well. Since the question is multiple choice, a short cut to answering the question (rather than calculating the pH's) is to find the choice with the largest value. The largest choice of the possible answers is choice A.
