Final answer:
option a,NH₄Br is an acidic salt because NH₄⁺, the ammonium ion, acts as a weak acid by donating a proton in water while the bromide ion is neutral, leading to an overall acidifying effect.
Step-by-step explanation:
To determine whether the salt NH₄Br is acidic, basic, or neutral, we need to consider the properties of its constituent ions. The ammonium ion (NH₄⁺) is the conjugate acid of ammonia (NH₃), which is a weak base. Therefore, NH₄⁺ will have a tendency to donate a proton (H⁺) in water and form NH₃, thus releasing H⁺ ions and making the solution acidic.
The bromide ion (Br⁻), on the other hand, is the conjugate base of hydrobromic acid (HBr), which is a strong acid. Because strong acids completely dissociate in solution, their conjugate bases are neutral. Thus, Br⁻ will not significantly affect the acidity or basicity of the solution.
Since the acidic influence of NH₄⁺ is not countered by Br⁻, the overall effect of NH₄Br in solution is to produce an acidic solution. Hence, NH₄Br is best classified as an acidic salt.