Question

$5g$ of zinc is treated separately with an excess of
(a) dilute hydrochloric acid and
(b) aqueous sodium hydroxide.
The ratio of the volumes of $H_2$ evolved in these two reactions is :

• A. 1 : 1
• B. 2 : 1
• C. 1 : 4
• D. 1 : 2

Answer 1

The correct option is A 1 : 1

$Zn+2NaOH\to N{a}_{2}Zn{O}_2+H_{2}Zn+2HCl\to ZnC{l}_2+H_2$
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According to stoichiometry in both the reaction, equal number of moles of $H_2$ is evolved.
Hence, option "a" is correct.