Each of the following solutions has a concentration of 0.1 mol/L. Compare the hydronium-ion concentration and pH in each pair, and explain why they are different.

Question

a) H2SO4(aq) vs. H2SO3(aq)

b) H2S(aq) vs. NH3(aq)

Answer 1

a) H2SO4 is a strong acid (at least the first H is) and H2SO3 is a weak acid (both H are weak).
The H3O^+ of H2SO4 is essentially the molarity. For H2SO3, you must set up an ICE chart from
H2SO3 ==> H^+ + HSO3^-
and solve for H^+

For H2S,
H2S ==> H^+ + HS^-
Set up ICE chart and solve for H^+.

For NH3,
NH3 + HOH ==> NH4^+ + OH^-
Set up ICE chart and solve for OH^- and convert to pH.
There isn't anything difficult about this question but it's a lot of leg work to get it done.
Post your work if you get stuck.