1. Some basic concept of chemistry — Chemistry STD 11 Science — Question

$2 Fe ^{2+}+ H _{2} O _{2} \rightarrow x A + y B$

(in basic medium)

$2 MnO _{4}^{-}+6 H ^{+}+5 H _{2} O _{2} \rightarrow x ^{\prime} C + y ^{\prime} D + z ^{\prime} E$

(in acidic medium)

The sum of the stoichiometric coefficients $x , y , x ^{\prime}, y ^{\prime}$ and $z ^{\prime}$ for products $A , B , C , D$ and $E ,$ respectively, is............

If the above equation is balanced with integer coefficients, the value of $z$ is____