Question

Additional Practice Questions

5. If you had a pH of 4.30 in a 5.00 L sample, how many
moles of hydronium do you have?

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* 10^(-4.3)mol/L=5.10^(-4.3)moles=2.5* 10^(-4)~moles`