Calculation:
When white phosphorous reacts with chlorine:
P4 + 6Cl2 → 4PCl3
PCl3 + 3H2O → H3PO3 + 4HCl ]*4
P4 +6Cl2 +12H2O → 4H3PO3 +12HCl
Moles of white P= 62/124 = 0.5mol
1mol of white P4 produces HCl = 12mol
0.5 mol of white P4 will produce HCl = 12*0.8 = 6mol
Mass of HCl = 6*36.5 = 219.0g