Answer
The pH of that solution is equal to 5.3
Work Step by Step
1. Calculate the pH Value
$pH = -log[H_3O^+]$
$pH = -log( 5 \times 10^{- 6})$
$pH = 5.30103$
2. Determine the right number of significant figures.
The $[H_3O^+]$ had 1 significant figures: $5 \times 10^{-6}$.
So, there must be only 1 number on the right of the decimal point of the pH.
- Round the number to 1 decimal place:
$pH = 5.3$
