Which combination cannot be used for the preparation of hydrogen gas in the laboratory? Zn/conc.H_(2)SO_(4)"II) " Zn//dil.HNO_(3) III) pure Zn/dil. H_(2)SO_(4) IV) granulated Zn/dil. HCl

Which combination cannot be used for the preparation of hydrogen gas i

1.	Which combination cannot be used for the preparation of hydrogen gas in the laboratory? Zn/conc.H_(2)SO_(4)"II) " Zn//dil.HNO_(3) III) pure Zn/dil. H_(2)SO_(4) IV) granulated Zn/dil. HCl
Answer» I and II I, II, III III only I and III Answer :B