Hydrolysis of Salts

 Yesterday we discussed the uses of salts and today, I want us to discuss what happens when we dissolve a salt in water. In order to keep things as simple as possible, I want to say that when we dissolve a salt in water, the salt is interacting with the water in a unique way. We can say that the salt is reacting with the water. 


When a substance is reacting with water, we say that the substance is undergoing hydrolysis. As such, the reaction of a salt with water is called hydrolysis of the salt.


The nature of the solution that is formed when a salt is dissolved in water depends on the way the salt is hydrolyzed in solution. Generally speaking;

- When a salt is formed from a strong acid and a strong base, the salt solution is neutral.

- When a salt is formed from a strong acid and weak base, the salt solution is acidic

- When a salt is formed from a weak acid and a strong base, the salt solution is basic.


Let us now see the hydrolysis of a few salts to substantiate our argument; 

- Consider the salt NaF. The dissolution of this salt in water produces the sodium ion and the fluoride ion. You have to note that the salt is formed from HF (a weak acid due to the high electronegativity of F) and NaOH (a strong base). The fluoride ion interacts with water as follows;

F^-(aq) + H2O(l) --> HF(aq) + OH^-(aq). The hydroxide ion produced by this equation makes the NaF solution basic.


- Consider the salt NH4Cl. The dissolution of this salt in water produces the ammonium ion and the chloride ion. The salt is formed from hydrochloric acid (a strong acid)  and ammonia (a weak base). The ammonium ion interacts with water as follows;

NH4^+(aq) + H2O(l) -->H3O^+(aq) + NH3(aq). The presence of the hydronium ion (H3O^+) makes the NH4Cl solution acidic.


- Consider a solution of NaCl. The dissolution of the salt in water produces sodium and chloride ions. The salt is formed from HCl(a strong acid) and NaOH (a strong base). The resulting solution is therefore found to be neutral.


As an assignment, decide whether a solution of these salts would be acidic, neutral or basic;

i) CH3COONa

ii) (NH4)2SO4

iii) NaNO3

Type your answers in the comments box below this post.


Hope you enjoyed our lesson today?

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Do you have assignments, term papers, projects and difficult homework questions? Contact us for help now! We also offer home and remote tutoring services to students at all levels in science subjects.


Or visit; www.toleYesterday we discussed the uses of salts and today, I want us to discuss what happens when we dissolve a salt in water. In order to keep things as simple as possible, I want to say that when we dissolve a salt in water, the salt is interacting with the water in a unique way. We can say that the salt is reacting with the water. 


When a substance is reacting with water, we say that the substance is undergoing hydrolysis. As such, the reaction of a salt with water is called hydrolysis of the salt.


The nature of the solution that is formed when a salt is dissolved in water depends on the way the salt is hydrolyzed in solution. Generally speaking;

- When a salt is formed from a strong acid and a strong base, the salt solution is neutral.

- When a salt is formed from a strong acid and weak base, the salt solution is acidic

- When a salt is formed from a weak acid and a strong base, the salt solution is basic.


Let us now see the hydrolysis of a few salts to substantiate our argument; 

- Consider the salt NaF. The dissolution of this salt in water produces the sodium ion and the fluoride ion. You have to note that the salt is formed from HF (a weak acid due to the high electronegativity of F) and NaOH (a strong base). The fluoride ion interacts with water as follows;

F^-(aq) + H2O(l) --> HF(aq) + OH^-(aq). The hydroxide ion produced by this equation makes the NaF solution basic.


- Consider the salt NH4Cl. The dissolution of this salt in water produces the ammonium ion and the chloride ion. The salt is formed from hydrochloric acid (a strong acid) and ammonia (a weak base). The ammonium ion interacts with water as follows;

NH4^+(aq) + H2O(l) -->H3O^+(aq) + NH3(aq). The presence of the hydronium ion (H3O^+) makes the NH4Cl solution acidic.


- Consider a solution of NaCl. The dissolution of the salt in water produces sodium and chloride ions. The salt is formed from HCl(a strong acid) and NaOH (a strong base). The resulting solution is therefore found to be neutral.


As an assignment, decide whether a solution of these salts would be acidic, neutral or basic;

i) CH3COONa

ii) (NH4)2SO4

iii) NaNO3

Type your answers in the comments box below this post.


Hope you enjoyed our lesson today?

Follow our page and share!

Do you have assignments, term papers, projects and difficult homework questions? Contact us for help now! We also offer home and remote tutoring services to students at all levels in science subjects.




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