Question

What is the pH of a solution of $KBr$?

Answer 1

Hint: When a solution of acid reacts with a solution of a base an acid-base reaction or a neutralization reaction takes place.
When the resulting solution contains equal amounts of hydronium ions and hydroxyl ions it is a neutral solution.
When a strong acid reacts with a strong base, the solution becomes neutral as the conjugate ions combined are of very limited strength to cause any distinct difference in pH from the neutral pH.

Complete answer:
$KO{H_{(aq)}} + HB{r_{(aq)}} \to KB{r_{(aq)}} + {H_2}{O_{(l)}}$
$KBr$ is the salt formed by the reaction between a strong acid$ - HBr$and a strong base -$KOH$
Hydrolysis is not caused by the cation ${K^ + }$ or the anion $B{r^ - }$when they react and the solution has a neutral pH of $7$ .
$H + $or $OH - $ ions are not given during the reaction as $K + $ ions do not act as an acid $ - $ it is a neutral cation and $Br - $is a neutral conjugate base of the strong acid$HBr$ and is neutral.
$KBr$is a neutral salt, both the ions do not react and the solution is neutral.
$KBr$ the solution is made from a neutral salt and the pH $ = 7$
In solution, the ${K^ + }$ions are attracted to negatively charged oxygen atoms in water and $B{r^ - }$ are attracted to positively charged hydrogen in water. The interaction of both the ions is not significant enough to cause any change in the structure of the water molecules.
$K + $+ is not a strong cation to break the water bond and $Br - $ is not a strong anion to break the water bond and hence the pH of the aqueous solution does not change. When the cation and the anion do not hydrolyze the solution is neutral.

Note:
According to Bronsted and Lowry's theory on acid-base reaction, the neutralization reaction occurs when aqueous solutions of acids and bases that are reacting are due to the reaction between hydronium ions and hydroxyl ions to form water. Solutions that contain hydrated salts or hydrated metal ions have a pH value that is determined by the extent of hydrolysis of the ions in the solution.
$KBr$is neither acidic nor basic and so a solution of it has a pH of $7$ .
pH depends on the strength of the acid and the base and how much of it is dissolved in a given volume of water.
If the dissociation constant of an acid ${K_a}$ is equal to the dissociation constant ${K_b}$ then pH $ = 7$ and the solution is neutral.