How many moles of electrons are needed for the reduction of `20mL` of `0.5M` solution of `KMnO_(4)` in acid mediumgt

Explanation

Moles of `KMnO_(4) = M xx V(L) = 0.5 xx 20 xx 10^(-3) = 10^(-2) [ :' Mn^(7+) +5e^(-) rarr Mn^(2+)]`
`:' 1 mol KMnO_(4)` required `= 5 "mole"^(-)`
`:. 10^(-2) mol KMnO_(4)` required `= 5 xx 10^(-2) "mole"^(-)`