Identify the correct statements from the following. (i) $\mathrm{Zn}$ reacts with dilute $\mathrm{HCl}$ and…
Identify the correct statements from the following.
(i) $\mathrm{Zn}$ reacts with dilute $\mathrm{HCl}$ and aqueous $\mathrm{NaOH}$ solution separately and liberates hydrogen.
(ii) Ti and Zr form interstitial hydrides.
iii) The viscosity of $\mathrm{H}_2 \mathrm{O}$ is more than the viscosity of $\mathrm{D}_2 \mathrm{O}$.
(i), (ii), (iii)
(i), (iii)
(i), (ii)
(ii), (iii)
Solution
$
\begin{aligned}
& \text { (i) } \mathrm{Zn}(s)+2 \mathrm{HCl}(a q) \longrightarrow \\
& \mathrm{Zn}^{2+}(a q)+2 \mathrm{Cl}^{-}(a q)+\mathrm{H}_2(g) \\
&
\end{aligned}
$
Zn comes into contact with $\mathrm{HCl}$ acid. It replaces the hydrogen from $\mathrm{HCl}$ molecule.
$
\mathrm{Zn}(\mathrm{s})+2 \mathrm{HCl} \longrightarrow \mathrm{ZnCl}_2+\mathrm{H}_2
$
(ii) Hydrides are classified into three categories, according to the nature of their bonding. Saline hydrides have a covalent bond, interstitial hydrides have a metallic bond and $d$-block elements make interstitial hydrides.
(iii) Viscosity of $\mathrm{H}_2 \mathrm{O}$ is more than the viscosity of $\mathrm{D}_2 \mathrm{O}$. This statement is wrong