How many moles of H2SO4 are needed to react with an equivalent of NaOH to produce 165 moles of sodium sulfate?

Question

2 NaOH + H2SO4 → Na2SO4 + 2 H2O

I know the answer is 82.5 but I don't understand how to get there.

Answer 1

Hello, Brianna,

I agree with you - I don't see the rationale to say we need 82.5 moles of H₂SO₄ to make 165 moles of sodium sulfate. The balanced equation says that 85.5 moles of H₂SO₄ would only produce 83.5 moles of the sulfate.

I suspect the question is written incorrectly. We do need 82.5 moles of NaOH to make 165 moles of Na₂SO₄. That's the only place we can find a need for 82.5 moles.