Question

Additional Practice Questions

Answer 1

Moles of hydronium (H₃O⁺) : 2.5 x 10⁻⁴

Further explanation

Given

pH = 4.3

V sample = 5 L

Required

moles of H₃O⁺(hydronium)

Solution

pH = - log [H₃O⁺]

4.3 = - log [H₃O⁺]

$\tt [H_3O^+]=10^{-4.3}~M=10^{-4.3}mol/L$

Moles of hydronium for 5 L sample :

$\tt 5~L\times 10^{-4.3}mol/L=5.10^{-4.3}moles=2.5\times 10^{-4}~moles$