Describe how a buffer solution based on hydrochloric acid can act as a buffer. (5)

HCl ⇌ H++ Cl- (1)Added alkali: H⁺ reacts with added alkali/OH^- (1) Equilibrium shifts right forming Cl^- or H⁺ (1) Added acid: Cl^- reacts with added acid/H⁺ (1) Equilibrium shifts left forming HCl (1)