We need to make 10 grams of NaCl, How many moles of HCl should we start with? How many moles of sodium sulfate do we need to start with?

Question

given the equation Na2SO4 + 2HCl → H2SO4 + 2NaCl we need to make 10 grams of NaCl. How many moles of HCl should we start with? How many moles of sodium sulfate do we need to start with?

Answer 1

Actually, this reaction as written does not take place. Mixing Na₂SO₄ with HCl ==> NO REACTION. However, as an exercise in calculating moles and mass, you would proceed as follows.

Na2SO4 + 2HCl → H2SO4 + 2NaCl

10 g NaCl x 1 mol NaCl/58 g = 0.17 moles NaCl

moles Na2SO4 needed = 0.17 mol NaCl x 1 mol Na2SO4/2 mol NaCl = 0.086 moles Na2SO4 needed

moles HCl needed = 0.17 mol NaCl x 2 mol HCl/2 mol NaCl = 0.017 moles HCl needed