Potassium walks into the club and Sulphate takes notice.
Sulphate leaves Magnesium for Potassium
The displacement reaction
How does the displacement reaction work? The reaction starts as Magnesium Sulphate + Potassium but as it starts to react it ends as Potassium Sulphate + Magnesium or MgSO4 + K = KSO4 + Mg.
The displacement reaction
The reason the potassium (K) displaces the magnesium (Mg) is that the K is more reactive than the Mg, in the reactivity series, so it replaces it in the equation.