Question

A buffer contains significant amounts of ammonia and ammonium chloride. (Part A) Enter an equation showing how this buffer neutralizes added aqueous acid (HNO3). Express your answer as a chemical equation. Identify all of the phases in your answer. (Part B) Enter an equation showing how this buffer neutralizes added aqueous base (NaOH). Express your answer as a chemical equation. Identify all of the phases in your answer. ** Make sure to identify ALL phases (states) in your answer **

Answer 1

Answer 2

1. Part.A

A buffer is any type of substance that will resist pH change when H⁺ or OH^- is added.

When a weak acid and its conjugate base are added, they will form a buffer

The equations:

For the weak base equilibrium:

B(aq) + H₂O(l) <------------> BH⁺(aq) + OH^-(aq)

Weak base = B;

Conjugate acid = BH⁺

Neutralization of OH- ions:

BH⁺(aq) + OH^-(aq) <-------> B(aq) + H₂O(l); in this case, OH^- is neutralized by BH⁺, as well as B is created

Neutralization of H⁺ ions:

B(aq) + H⁺(aq) <--------> BH⁺(aq)

So, Equation showing how this buffer neutralizes added HNO₃ is

NH₄OH (aq) + HNO₃ (aq) ----------->  H₂O (l)+ NH₄NO₃ (aq)

Part.B

Equation showing how this buffer neutralizes added base (NaOH) is :

NH₄Cl (aq) + NaOH (aq) ------------> NH₃ (aq) + NaCl (aq) + H₂O (l)