Question

What mass of HCIO4 must be present in 0.500 L of solution to obtain a solution with a pH=3.5 value

Answer 1

Solution.

$pH = -lg[H3O^+]$

$[H3O^+] = 10^{-pH}$

$[H3O^+] = 3.16 \times 10^{-4} M$

$C = \frac{m}{M \times V}$

$m = C \times M \times V$

$m = 3.16 \times 10^{-4} \times 100.46 \times 0.500 = 0.016 \ g$

Answer:

m(HClO4) = 0.016 g