Salt is the most well-known ingredient used in all food items to make it delicious. However, what is the mystery behind this?
Let’s discuss !!
Salt is an ionic compound that contains positively charged ions (cation) and negatively charged ions (anion).
Chemical Bonding in Salt :
As you know that salt is an ionic compound and the ionic compound is formed by the complete transfer of an electron from one atom to another.
This complete transfer of electron/s from one atom to another atom results in an ionic bond.
Example of Ionic Bond:
In NaCl, sodium atoms lose one valence electron whereas chlorine atom gains one electron to complete their valence shell and both atoms become stable.
This complete transfer of an electron from the sodium atom to the chlorine atom results in an ionic bond between them, As a result, NaCl ( also known as common salt) is formed, which is an ionic compound.
5 Methods for making salts:
Following are the five methods for the preparation of salts.
- Acid-Base reaction
- Acid-Metal reaction
- Acid-Metal oxide reaction
- Acid-Metal carbonate reaction
- Salt-Salt reaction
Acid-Base reaction :
The first method for making salt is the acid-base reaction method.
When acid reacts with a base, it results in the formation of salt and water.
Examples of acid-base reaction:
Do you know !!
An acid-base reaction is also known as a neutralization reaction because the salt formed as a result of this reaction is neutral in nature ( pH 7 ), having neither acidic nor basic properties. Therefore, this salt is known as neutral salt or normal salt.
For example, NaCl , NaNO3 , Na2SO4 etc.
When acid reacts with metal, results in the formation of salt and hydrogen gas.
Few acid-metal reaction examples are as follow:
Acid-Metal oxide reaction:
When acid reacts with metal oxide, results in the formation of salt and water.
Few acid-metal oxide reaction examples are as follow:
Acid-Metal carbonate reaction:
When acid reacts with metal carbonate, results in the formation of salt, carbon dioxide and water.
Acid-metal carbonate reaction example is as follow:
When salts react together, results in the formation of salts.
Salt-salt reaction example is as follow:
How salt is formed ?
Salt formation takes place when the hydrogen atoms of the acid are partially or totally replaced by metal atoms.
This is an acid-base reaction ( also known as neutralization reaction because in this reaction acid (HCl) reacts with a base (NaOH) to produce a salt (NaCl) and water.
Both salt and water are neutral in nature with pH 7 . Therefore, the acid-base reaction results in the formation of normal salts.
In this reaction metal atom (Na) of a base replaces a hydrogen atom of acid results in the formation of sodium chloride (NaCl).
Few more Examples !!
Acids and their common salts:
Here HNO3 .H2SO4 and H3PO4 are acids.
NaNO3, Na2SO4 and Na3PO4 are their respective salts formed after the replacement of hydrogen from an acid.
Properties of salts:
- Salts are ionic compounds.
- Salts are made up of negatively charged anions and positively charged cations.
- Hard & brittle
- Crystalline solids
- Potassium (K),Ammonium (NH4+ ) & Sodium (Na) salts are soluble in water
- Nitrites,Nitrates & Bicarbonates salts can be soluble in water
- Metallic oxides, metallic carbonates, hydroxides,phosphates & sulphides salts are insoluble in water
Uses of Salts:
- Food flavouring
- Food preservation
- Tanning,dyeing & bleaching
- Prevention of ice during winter
- Removes stains & grease
- Used in manufacture of soap & detergent etc