Answer
The ratio is 300 to 1. ** Significant figures.
The ratio is 398 to 1. ** Without significant figures.
Work Step by Step
1. Calculate the hydronium concentrations when pH = 3.0 and when pH = 5.6.
$[H_3O^+] = 10^{-pH}$
$[H_3O^+] = 10^{- 3}$
$[H_3O^+] = 1 \times 10^{- 3}M$
$[H_3O^+] = 10^{-pH}$
$[H_3O^+] = 10^{- 5.6}$
$[H_3O^+] = 2.512 \times 10^{- 6}M$ ** Without significant figures.
$[H_3O^+] = 3 \times 10^{-6}M$ ** With significant figures.
2. Now, divide the first number by the second one
$\frac{1\times 10^{-3}}{2.512 \times 10^{-6}} = 398$ ** Without significant figures.
$\frac{1\times 10^{-3}}{3 \times 10^{-6}} = 300$** With significant figures.
