Question

Identify Arrhenius acids and bases among the following:
$\begin{array}{cc}1.NaCl& 2.HCl\\ 3.Cu{\left(OH\right)}_2& 4.NaOH\\ 5.H_{2}S{O}_4& 6.HN{O}_3\\ 7.KOH& \end{array}$

• A. 1, 2 and 5 are acids and 3, 4 and 7 are bases
• B. 2, 3 and 5 are acids and 1, 4, 6 are bases
• C. 4, 6 and 7 are acids and the rest are bases
• D. 2, 5 and 6 are acids and 3, 4 and 7 are bases

Answer 1

The correct option is D

2, 5 and 6 are acids and 3, 4 and 7 are bases

Arrhenius acid should dissociate $H^{+}$ ions on dissolving in water. So, only 2, 5 and 6 are Arrhenius acids.
Arrhenius bases should dissociate in water to form $O{H}^{-}$ ions. Hence, 3, 4 and 7 are bases.

$\begin{array}{cc}\text{Substance}& \text{Examples}\\ \text{Arrhenius Acid}& HCl,H_{2}S{O}_4,HN{O}_3\\ \text{Arrhenius Base}& Cu{\left(OH\right)}_2,NaOH,KOH\end{array}$