Some Basic Concepts of Chemistry - Result Question 28
Integer Answer Type Questions
29. When the same amount of zinc is treated separately with excess of sulphuric acid and excess of sodium hydroxide, the ratio of volumes of hydrogen evolved is
(1979, 1M)
(a) $1: 1$
(b) $1: 2$
(c) $2: 1$
(d) $9: 4$
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Answer:
Correct Answer: 29. (a)
Solution:
- The balanced chemical reaction of zinc with sulphuric acid and NaOH are
$\begin{aligned} & \mathrm{Zn}+\mathrm{H}_2 \mathrm{SO}_4 \longrightarrow \mathrm{ZnSO}_4+\mathrm{H}_2(\mathrm{~g}) \uparrow \\ & \mathrm{Zn}+2 \mathrm{NaOH}+2 \mathrm{H}_2 \mathrm{O} \longrightarrow \mathrm{Na}_2\left[\mathrm{Zn}(\mathrm{OH})_4\right]+\mathrm{H}_2(\mathrm{~g}) \uparrow \\ \end{aligned}$
Since, one mole of $\mathrm{H}_2(\mathrm{~g})$ is produced per mole of zinc with both sulphuric acid and NaOH respectively, hydrogen gas is produced in the molar ratio of $1: 1$ in the above reactions.
BETA
