Lewis acids are those substances which:

Four species are listed below:
$i. \, HCO_3^-$
$ii. \, H_3O^{+}$
$iii. \, HSO_4^-$
$iv. \, HSO_3F$
Which one of the following is the correct sequence of their acid strength?

$HF + HClO_4 \rightleftharpoons H_2F^{+} + ClO_4^-$ and $H_2O + H_2PO_4^- \rightleftharpoons H_3O^{+} + HPO_4^{2-}$ Select the group of acidic species present on the right side of the equilibrium.

$NaOH$ is a strong base because......

Which of the following salts is acidic?

If $pK_b$ of a base is $5$,then $K_a$ of its conjugate acid will be