Write the buffer solution equation then write two chemical equations showing how a buffer reacts with a). NaOH and b). HCl. Please explain which component of the buffer reacts with each.

Question

Write the buffer solution equation then write two chemical equations showing how a buffer reacts with a). NaOH and b). HCl. Please explain which component of the buffer reacts with each.

Context: 15 ml NH3 (base component) and 15 ml NH4Cl (acid component) were added together. Then 30 ml of H2O was added. Half the solution was poured into another beaker to make two separate solutions. NaOH was added to one solution and HCl was added to another solution.

Answer 1

A buffer consists of a weak acid + the conjugate base or a weak base and the conjugate acid. The present problem is one of a weak base (NH₃) and the conjugate acid (NH₄Cl).

When a base (NaOH) is added, it will react with the acid (NH₄Cl), and when an acid (HCl) is added, it will react with the weak base (NH₃).

(a) NaOH + NH₄Cl ==> NH₃ + H₂O + NaCl

(b) HCl + NH₃ ==> NH₄Cl