CSEC Chemistry · May/June 2011 · Paper 1 · Question Q5

Which of the following ions requires the LARGEST number of moles of electrons to liberate one mole of it?

1. (A)\text{Al}^{3+}
2. (B)\text{Cl}^-
3. (C)\text{Cu}^{2+}
4. (D)\text{O}^{2-}