Stoichiometry Question

Question

Chlorine is used by textile manufacturers to bleach cloth.  Excess chlorine is destroyed by its reaction with sodium thiosulfate, Na2S2O3:

Na2S2O3(aq) + 4Cl2(g) + 5H2O(aq) 🡪 2NaHSO4(aq) + 8HCl(aq)

How many grams of Na2S2O3 are needed to react with 2.65 mol of H2O?

Answer 1

You will need to convert moles of water to moles of Na2S2O3 using the coefficients in the balanced chemical equation (5:1). Then convert moles of Na2S2O3 into grams of Na2S2O3 using the molar mass of Na2S2O3. The dimensional analysis will really help here!