Question

Which of the following is true about a solution that has $\left[OH\right]=1.0\times {10}^{-8}$M?

• A. The pH is 8 and the solution is acidic
• B. The $\left[H^{+}\right]=1.0\times {10}^{-8}$ M and the solution is basic
• C. The pH is 6 and the solution is acidic
• D. The $\left[H^{+}\right]=1.0\times {10}^{-6}$M and the solution is basic
• E. The $\left[H^{+}\right]=1.0\times {10}^{-14}$M and the solution is neutral

Answer 1

The correct option is C The pH is 6 and the solution is acidic

$[OH{]}^{-}=1.0\times {10}^{-8}$
$\left[H^{+}\right]=\frac{K_w}{[OH{]}^{-}}=\frac{1.0\times {10}^{-14}}{1.0\times {10}^{-8}}=1.0\times {10}^{-6}$
$pH=-log\left[H^{+}\right]=-log1.0\times {10}^{-6}=6$
Hence, the pH is 6 and the solution is acidic.