I really feel like I am simply overlooking one thing easy.
HCOOH H2O <-> HCOO- H3O
Ka = 1.8 x 10^-4 = x^2 / 0.220-x
x = [H3O ] = 0.00629 M
Formic acid wouldnt dissociate completely, its dissociation is sqrt((one million.8*10^-4)/0.15)*100%, which equals to three,40 six% and that is far much less that 5%, with a view to take the focus of acid after dissociation as 0,15 too, cuz it dissociates pretty. So Ka=x^2/c , x=sqrt(Ka*c), ph=-log(x), ph=2.3 . reply is B
This post is last updated on hrtanswers.com at Date : 1st of September – 2022