Hydrolysis of Salts - pH analysis... Will Rate for sure?

Question

Explanation with Equation to Show Hydrolysis of the following.

1. Potassium Chloride

- Turned Green to universal indicator

- pH = 7.5

2. Sodium Acetate

- Turned Bluish Green to universal indicator

- pH = 8.5

3. Ammonium Chloride

- Turned Yellow to universal indicator

- pH=6.5

Answer 1

The potassium chloride should be neutral (well, really an extremely weak base - the Kb for HCl is negligible as it is a strong acid) as are all salts of strong acids.  The slight basicity is probably due to impurities in either the water or KCl or due to inaccuracy in reading the pH (was a meter used, or was pH estimated from the indicator color?).

Sodium acetate is the salt of a weak acid (acetic acid), so it will hydrolyze in water:

CH3COONa + H2O <-----> CH3COOH + Na+ OH-

As can be seen from the equation, OH- is formed, making the solution more basic and explaining your result.

Ammonium chloride contains the ammonium ion, the conjugate acid of ammonia, and so it will dissociate in water:

NH4Cl <------> NH3 + H+ + Cl-

Or, if you prefer hydronium to H+:

NH4Cl + H2O <------> NH3 + H3O+ + Cl-

As the H+ product indicates, the solution will become acidic, explaining your observations.