Question

What is the pH of a solution with an H3 O+ concentration of 1×10−⁹ ?

A) 7
B) 9
C) 5
D) 3

Answer 1

The pH of a solution with an H3O+ concentration of 1×10−9 is 9, indicating that the solution is basic.

Step-by-step explanation:

The pH of a solution with an H3O+ concentration of 1×10−9 is calculated using the formula pH = –log[H3O+]. Plugging in the given concentration, we calculate:

pH = –log(1×10−9) = 9

Therefore, the pH of the solution is 9, which means the solution is basic. When the coefficient in front of the 10 in the scientific notation of H3O+ concentration is 1, the pH is equal to the exponent, but with an opposite sign.