A student prepares a buffer containing comparable amounts of aqueous ammonia, \(\text{NH}_3\text{(aq)}\), and ammonium chloride, \(\text{NH}_4\text{Cl(aq)}\). The student then adds a small amount of hydrochloric acid, \(\text{HCl(aq)}\), without exceeding the buffer capacity. Which of the following is the net ionic equation for the principal reaction that occurs?