Preparation of Salts

 Today, our focus would be on the preparation of salts. We are concerned about how we can make salts. I want to remind you again that a salt is made when hydrogen ion in an acid is replaced by another cation. Let us now consider some of ways by which salts can be made;


1) Reaction of a dilute acid and metal;

A salt can be formed when a single replacement reaction occurs between a dilute acid and a metal. The metal used here must be above hydrogen in the activity series. For example;

Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g)

This kind of reaction is most times given as one of the chemical properties of acids.

2) Neutralization reaction: As I have explained previously, a neutralization reaction occurs between an acid and a base to form a salt and water only. This is one of the most important ways by which soluble salts are formed.

For example; KOH(aq) + HCl(aq) -> KCl(aq) + H2O(l)

H2SO4(aq) + CuO(s) -> CuSO4(aq) + H2O(l)

3) Dilute acid and carbonate: One of the chemical properties of acid is the ability to react with carbonates to form salt, water and carbon dioxide. A typical example of this is the reaction;

Na2CO3(aq) + 2HCl(aq) --> 2NaCl(aq) + H2O(l) + CO2(g)

4) Combination of constituent elements: This is a common method for the preparation of insoluble salts. The elements that compose the salt can be heated directly as follows; Fe(s) + S(s) --> FeS(s). This method can only be used to prepare binary salts(a salt composed of two elements only).

5) Double decomposition: This can also be called double replacement reaction. In this kind of reaction, the cations on the reactant side exchange anion partners on the products side. For example;

AgNO3(aq) + NaCl(aq) --> AgCl(s) + NaNO3(aq)


We are going to be live on our Facebook page for a webinar on the topic How to study Chemistry and Understand It at 2pm WAT. Kindly convert this time to your local time zone and do your best to join using the link; https://fb.me/e/65saALruu?mibextid=Gg3lNB


Remember that you can ask your questions and get answers during the live session.





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