When 1 g of zinc was treated with dil. H2SO4,360cm3 of H2 gas at 15∘C and 758 torr. was liberated. When 1g zinc was added to copper nitrate solution 0.965 g of copper was displaced. Calculate the equivalent weight of zinc and copper (1L of H2 gas weighs 0.09 g).

(i)              P1=758 torr; V1=360cm3T1=15+273=288K;P2=760 torr; V2=?,T2=273K.Using gas equation, we have :                     P1V1T1=P2V2T2;V2=P1V1T1×T2P2=758 torr. ×360cm3×273K288K×760 torr.   or V2=340.4cm3.1000cm3(=1L) of H2 weighs =0.09g ∴340.4cm3 of H2 weighs =0.09×340.41000g=0.0306g. Eq. wt. of Zn=Wt. of Zn×1.008Wt. of H2 at NTP=1×1.0080.0306 =32.9 g   (ii)   wt. of Zn=1g , Wt. of Cu=0.965g  Eq. wt. of Cu=Eq.wt. of Zn×wt. of Cuwt. of Zn                    =32.9×0.9651=31.75