Equivalent weight of a divalent metal is 24. The volume of hydrogen liberated at STP by 12 g of the same metal when added to excess of an acid solution is:
Equivalent weight =molecular weightvalency
24=Mw2
Mw=48= Molecular weight of divalent metal X
Moles of X=1248=0.25
X+2HCl→XCl2+H2
0.25 0.50 − −
0.25 0.25
Moles of H2 produced =0.25 moles
Volume of 0.25 moles H2=0.25×22.4=5.6 litres