Question

a) Which is the strongest acid among the hydrogen halides? Give one reason $[X=F,Cl,Br,I]$.
b) Write the structure of chloric acid $\left(HCl{O}_3\right)$.

Answer 1

a) $HI$ is the strongest acid among the hydrogen halides. This is due to following reasons
(i) The weak $H-I$ bond requires less energy to dissociate.
(ii) Low heat of dehydration due to little association in aqueous solution.
(iii) Due to this, $\Delta H$ for the process $HX\left(aq\right)\to H^{+}\left(aq\right)+X^{-}\left(aq\right)$ is maximum for $HI$.
b) The structure of chloric acid $\left(HCl{O}_3\right)$ is as shown.