Formic acid (HCO2H) has a dissociation constant of 1.8 x 10^-4 M. The acid dissociates 1:1. What is the [H+] if 0.35 mole of for

Question

neonofarm [45]

3 years ago

15

Formic acid (HCO2H) has a dissociation constant of 1.8 x 10^-4 M. The acid dissociates 1:1. What is the [H+] if 0.35 mole of for

mic acid is dissolved in 1.0 liter of water?

Chemistry

1 answer:

Tju [1.3M] · Answer 1 · 2022-03-16T23:38:36+03:00

Initial [ HCO2H] = moles * volume
=0.35 moles * 1 L = 0.35 M

by using ICE table:

HCO2H ↔ H+ + HCO2-
initial 0.35 M 0 0
change - X +X +X
Equ (0.35 - X) X X

∴ Ka = [H+][HCO2-] / [HCO2H]

by substitution:

1.8 x 10^-4 = X^2 / (0.35-X) by solving for X

∴ X = 0.0079 or 7.9 x 10^-3

∴ [H+] = X = 7.9 x 10^-3 M