Which combination cannot be used for the preparation of hydrogen gas in the laboratory?
$I .$ Zinc/conc. $H_{2} S O_{4}$
$I I .$ Zinc/dil. $H N O_{3}$
$I I I .$ Pure Zinc/dil. $H_{2} S O_{4}$

Question

Which combination cannot be used for the preparation of hydrogen gas in the laboratory? I . Zinc/conc. H 2 S O 4 I I . Zinc/dil. H N O 3 I I I . Pure Zinc/dil. H 2 S O 4

TestHub · Accepted Answer

I . Zinc and conc. H 2 S O 4 gives S O 2 I I . Zinc and dil. H N O 3 gives N H 4 N O 3 . I I I . The reaction with pure zinc and dil. H 2 S O 4 is very slow.

Chemistry - Complete s-block Question with Solution | TestHub

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