In: Chemistry
Calculate the H3O+ concentration of the following reaction if the initial concentration of hydrocyanic acid is 0.0100 M. HCN(aq) + H2O(l) ⇔ H3O+ (aq) + CN– (aq) Kc=4.9 × 10^–10
HCN(aq) + H2O(l) ⇔ H3O+ (aq) + CN– (aq)
0.01 0 0 (initial)
0.01 - x x x (at equilibrium)
Kc= [H3O+] [CN-] / [HCN]
4.9*10^-10 = x*x / (0.01-x)
since Kc is very small, x will be very small and it can ignored as compared to 0.01
so,0.01 -x will be approximately 0.01
4.9*10^-10 = x*x / (0.01)
x= 2.2*10^-6 M
Since [H3O+] = x
concentration of H3O + = 2.2*10^-6 M