Consider the following reactions: NaCl + K_2 Cr_2 O_7+ H_2 SO_4 → A + KHSO_4+ NaHSO_4+ H_2 O; A + NaOH → B + NaCl + H_2 O; B + H_2 SO_4+ H_2 O_2 → C…

Consider the following reactions : $$\begin{aligned} & \mathrm{NaCl}+\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7+\mathrm{H}_2 \mathrm{SO}_4 \rightarrow \mathrm{~A}+\mathrm{KHSO}_4+\mathrm{NaHSO}_4+\mathrm{H}_2 \mathrm{O} \\ & \mathrm{~A}+\mathrm{NaOH} \rightarrow \mathrm{~B}+\mathrm{NaCl}+\mathrm{H}_2 \mathrm{O} \\ & \mathrm{~B}+\mathrm{H}_2 \mathrm{SO}_4+\mathrm{H}_2 \mathrm{O}_2 \rightarrow \mathrm{C}+\mathrm{Na}_2 \mathrm{SO}_4+\mathrm{H}_2 \mathrm{O} \end{aligned} $$ In the product ' C ', ' X ' is the number of $\displaystyle \mathrm{O}_2^{2-}$ units, ' Y ' is the total number oxygen atoms present and 'Z' is the oxidation state of Cr. The value of X+Y+Z is $\displaystyle \_\_\_\_$.