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.

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

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

2 answers

I suppose the easy way is to simply solve for H^+ and convert to pH. I recommend that you do that. I can get you started if you tell me what you know about it. In words, the difference between H2SO4 and H2SO3 is that the first H^+ is a strong acid in H2SO4 whereas both H^+ are weak for H2SO3. In pair b, H2S is a weak acid (H2O acts as a base for H2S) while NH3 is a weak base(H2O acts as an acid with NH3).
Thanks, solved it.