Chapter 18.4, Problem 48PP

Interpretation Introduction

Interpretation:

The equation in the titration of ammonium hydroxide with hydrogen bromide is to be written and $pH$ at equivalence point is to be checked.

Concept introduction:

Acid and base reacts to form salt and water.

Acid and base together neutralize each other.

Overall neutralization depends on strength of acid and base.

Answer to Problem 48PP

Equation:

$\begin{array}{l}N{H}_{4}OH+HBr\to N{H}_{4}Br+H_{2}O\\ Further\\ N{H}_4{}^{+}+H_{2}O\rightleftharpoons N{H}_3+H_3{O}^{+}\end{array}$

$pH$at equivalence point will be less than $7$

Explanation of Solution

When ammonium bromide is titrated with hydrogen bromide, reaction occurs as:

$\begin{array}{l}N{H}_{4}OH+HBr\to N{H}_{4}Br+H_{2}O\\ N{H}_4{}^{+}+H_{2}O\rightleftharpoons N{H}_3+H_3{O}^{+}\end{array}$

In the reaction, there is formation of hydroxyl ions, therefore $pH$at equivalence point will be less than $7$

Conclusion

Thus, reaction of ammonium hydroxide and hydrogen bromide produces ammonium bromide, ammonia, water and hydroxyl ions.