Question

question 3 of 10
what is the ph of a solution with h+ = 7.0 × 10^(-12)?
a. 11.15
b. 12.85
c. -12.00
d. -11.15

Explanation:

Step1: Recall pH formula

The formula for pH is $pH = -\log[H^{+}]$.

Step2: Substitute the given value

Given $[H^{+}]=7.0\times 10^{-12}$, then $pH = -\log(7.0\times 10^{-12})$.
Using the property of logarithms $\log(ab)=\log a+\log b$, we have $pH=-(\log7.0+\log(10^{-12}))$.
Since $\log(10^{-12})=- 12$ and $\log7.0\approx0.85$, then $pH=- (0.85 - 12)$.

Step3: Calculate the pH value

$pH=-0.85 + 12=11.15$.

Answer:

A. 11.15