Question

If you wanted to create a equimolar buffer using 1.0 mol of NaHS in 1.0L of water what acid would you need to add? how many moles of that acid do you need to add?

Answer 1

If NaHS is the base, then H2S must be the acid. If you have 1.0L of 1.0M NaHS, you will need to add 0.5 mol HCl. That will give you 0.5 mol of NaHS and 0.5 mol H2S.