Can we use conc. `H_(2)SO_(4)` for preparing hydrogen gas from zinc metal?

Conc. H_(2)SO_(4) is not

what happens if conc H_(2)SO_(4) is used in preparing hydrogen by its reaction with a metal?

Conc. H_(2)SO_(4) will not give any gas with :

Conc. H_(2)SO_(4) will not give any gas with

Conc. H_2SO_4 liberates hydrogen chloride gas from chlorides because

Which combination cannot be used for the preparation of hydrogen gas in the laboratory ? I. Zinc/conc. H_(2)SO_(4) II. Zinc/ HNO_(3) III. Pure zinc/dil. H_(2)SO_(4)