So B dissociates from A forming its own reactant, while A C combines with A displacing this B. So basically, C kicks out our B and forms a bond with A forming AC plus B. And this is a single displacement reaction or substitution reaction. Now, a very common example is when two moles of hydrochloric acid in an Aqueous state react with 1 mol of magnesium solid. This produces 1 mol of Mg CL, two in the Aqueous state, and 1 mol of diatomic H two in a gas state. So this is a single display for reaction in which our Mg kicks off this H, forming our reactant, and this H combines with another H forming a diatomic gas.