Question

Chlorine is used by textile manufacturers to bleach cloth. Excess chlorine is destroyed by its reaction with sodium thiosulfate, Na2S2O3, as follows:
Na2S2O3(aq) + 4Cl2( g) + 5H2O right-arrow 2NaHSO4(aq) + 8HCl(aq)

1)How many moles of HCl can form from 0.21 mol of Cl2?

2)How many moles of H2O are required for the reaction of 0.18 mol of Cl2?

3)How many moles of H2O react if 0.50 mol HCl is formed?

Answer 1

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

1)How many moles of HCl can form from 0.21 mol of Cl2?
0.21 mol Cl2 ( 8 mol HCl / 4 mol Cl2 ) = 0.42 mol HCl

2)How many moles of H2O are required for the reaction of 0.18 mol of Cl2?
0.18 mol Cl2 ( 5 mol H2O / 4 mol Cl2 ) = 0.225 mol H2O

3)How many moles of H2O react if 0.50 mol HCl is formed?
0.50 mol HCl ( 5 mol H2O / 8 mol HCl ) = 0.3125 mol H2O