Question

calculate moles of oxygen atoms in 0.68mol of KMnO4

Answer 1

Alright, so that means we have 0.68 mol of the compound


For each 1 mol of the compound, we have 4*1 oxygens (because there are four oxygens in the formula)
Therefore for each 0.68 mol of the compound, we have 4*0.68 moles of oxygen!