Question

How many moles of Cl- ions are needed to completely combine with 0.25 moles of Mg+2 ions?

Answer 1

Mg⁺² + 2Cl⁻ = MgCl₂

n(Mg⁺²)=0.25 mol

n(Cl⁻)=2n(Mg⁺²)

n(Cl⁻)=2*0.25=0.5 mol