what is the hydronium-ion concentration in a 0.35m solution of NaCO3? For carbonic acid, Ka1=4.2x10^-7 and Ka2=4.8x10^-11. (Kw=1.0x10^-14)

Answer 1

I'm sure you mean 0.35M solution. Do you know that 0.35M and 0.35m are not the same? This is a hydrolysis problem.
........CO3^2- + HOH ==> HCO3^- + OH^-
I.......0.35M..............0.......0
C.......-x.................x.......x
E.......0.35-x.............x.......x

Kb for CO3^- = (Kw/k2 for H2CO3) = (x)(x)/(0.35-x). Substitute and solve for x = (OH^-) an convert to pH.

Answer 2

Why is the last step is convert to pH? We are trying to find the hydroxide-ion concentration?not the pH

Answer 3

Nvm figured it out