• # question_answer 15) Calculate the oxidation number of sulphur, chromium and nitrogen in ${{H}_{2}}S{{O}_{5}},C{{r}_{2}}O_{7}^{2-}$ and$NO_{3}^{-}$. Suggest structure of these compounds. Count for the fallacy.

(i)$\overset{+1}{\mathop{H}}\,-\overset{-2}{\mathop{O}}\,-\underset{\underset{\underset{-2}{\mathop{O}}\,}{\mathop{||}}\,}{\overset{\overset{\overset{-2}{\mathop{O}}\,}{\mathop{||}}\,}{\mathop{S}}}\,-\overset{-1}{\mathop{O}}\,-\overset{-1}{\mathop{O}}\,-\overset{+1}{\mathop{H}}\,$ $x+2-8=0$ $x=+6$ Here, x is the oxidation state of sulphur. (ii) $\overset{-}{\mathop{O}}\,-\underset{\underset{O}{\mathop{||}}\,}{\overset{\overset{O}{\mathop{||}}\,}{\mathop{Cr}}}\,-O-\underset{\underset{O}{\mathop{||}}\,}{\overset{\overset{O}{\mathop{||}}\,}{\mathop{Cr}}}\,-\overset{-}{\mathop{O}}\,$ Let x be the oxidation state of chromium. $\therefore$ $2x-14=-2$ $x=+6$ (iii) Let oxidation state of nitrogen is $x-6=1$ $x=+5$