(a) 5 mol (b) 10 mol
(c) 20 mol (d) 2.5 mo
ANSWER SHOUD BE "a".
Zn reacts with HCl and form ZnCl2 and H2 .
Balance Reaction is Zn + 2HCl ----- ZnCl2 + H2 .
When 10 mol of Zn react with 10 mol of HCl then HCl is Limiting Reagent So HCl Completely React .........
So , 2mol of HCl gives 1 mol of H2 from Balance Reaction ..
So , 10 mol of HCl gives 5 mol of H2 gas from Balance Reaction ..
finally So , 5 moles of H2 gas are produced .