Salts Types Hydrolysis - Examples, Classification, Difference, FAQs

What is a SALT?

A chemical compound formed by the combination of positive ions called actions and negative ions called anions is called salt. The product obtained by this fusion of cations and anions has a net charge of zero i.e. a neutral compound. The ionic components contributing to the formation of salt can be polyatomic, monoatomic, organic or inorganic. The chemical composition of salt represents a 1:1 ratio of sodium and chloride ions. Salt is the general term used to describe a substance or a chemical compound formed as a result of a reaction taking place between an acid and a base.

The cation and an anion are the constituent elements of salt. This reaction between acid and base is called a neutralization reaction. Salt is made up of cation and anion as described above. A chemical product resulting from a neutralization reaction by replacing one or more than one hydrogen atom of an acid with other groups or elements capable of ionizing in the solution. Salts being an ionic compound tend to dissociate into cations and anions in the solution.

The cation part is always a metal cation or is derived from ammonium (NH₄+).Salts are named by mentioning the positively charged ion or cation part first followed by negatively charged ion or anion. The salt deposits are mined to get table salt from it. Table salt is processed which leads to elimination of contaminants and minerals present in it. It is further iodized by adding iodine content. The nutritional value of table salt and sea salt is more or less the same. But often, sea salt is most preferred over table salt being healthier. Salts containing an organic ion are termed as organic salts.

Also read -

• NCERT Solutions for Class 11 Chemistry
• NCERT Solutions for Class 12 Chemistry
• NCERT Solutions for All Subjects

Organic salt examples are – sodium acetate, sodium laurate.

Examples of salt:- Salt chemical name:- Sodium Chloride

The molecular formula of salt – NaCl.The salt water reaction is also termed hydrolysis and is represented as follows-

NaCl +H₂O → NaOH + HCl

Hydrolysis is the reverse of neutralization reaction wherein salt and water are products obtained in the reaction between acid and base.

Sodium chloride or table salt consists of sodium cation and chloride anion having a salt formula as NaCl. It is a major component used by everyone in day to day activities and in any interesting area of concern. Sodium hydroxide is neutralized by hydrochloric acid resulting in salt formation. The desired salt is obtained after the evaporation of the water content present in it. This strong acid and strong base reaction lead to the formation of an electrically neutral compound, NaCl being the salt chemical formula.

HCl + NaOH NaCl + H₂O

Calcium Chloride-

The calcium chloride and Sodium chloride salt are similar because of their white colour.

It is commonly used for the removal of ice from the road.

Potassium Dichromate -

This chemical comprises potassium, chromium and oxygen.

It is used as an oxidising agent in many chemical reactions.

It is toxic and must be handled cautiously.

Chromium is a potent carcinogen that can cause serious injuries if this is spilt on the skin.

Sodium bisulphate -

It is also specified as dry acid. It is prepared from sulfuric acid. It helps in decreasing the pH of pools and spas. It is hazardous for skin if mishandled.

Copper Sulphate-

Copper Sulphur and oxygen are the main components.

It is also used as an electrolyte in cells.

Physical and chemical properties of salt –

• Crystalline, bitter and hard chemical substances.

• Salt solution or saline solution is capable of conducting electricity.

• It is odourless having a salty taste. Salts are present in cube forms.

• Salt is water-soluble

• Salts are slightly soluble in alcohol but insoluble in a concentrated solution of hydrochloric acid (HCl).

• Salts are capable of absorbing moisture content from the surrounding i.e they are Hygroscopic.

Classification of salt:

How many types of salt are there?

There exist five types of salts as follows:

1. Normal Salt:

Electrically neutral salts are called Normal salts. Normal salts lack replaceable hydroxyl or hydrogen in their chemical formula. The hydrogen ions are replaced by metallic ions in the reaction. Neutral salt examples are: NaCl, KNO₃, etc.

2. Basic Salt:

When a partial or incomplete neutralization reaction takes place between acid and a base being weak and strong respectively, basic salts are obtained.

Eg: Calcium Carbonate (CaCO₃), Sodium Acetate (NaOOCCH₃), etc.

3. Acidic salt:

The acidic salt definition is as follows-

A neutralisation reaction between a strong acid and weak base results in the formation of acidic salt. NH₄Cl is obtained as a reaction product between strong acid – HCl and weak base – NH₃. An example of acidic salt is ammonium chloride.

4. Mixed salt:

Two salts of mixed proportions make a mixed salt. These two salts share a common cation or anion. A mixed salt example is CaOCl₂.

5. Double Salt definition:

Salts comprising more than one anion or a cation is called double salt. They ionize as two different salts when dissolved in water.

Eg: Potash alum – K₂SO₄.AL₂(SO₄)₃.24H₂O

Ammonium ion – (NH₄)₂Al₂(SO₄)₃.24H₂O

Mohr’s Salt – FeSO₄(NH₄)₂SO₄.6H₂O

Double salts always exist in a solid-state and are water-soluble. Isomeric properties are not shown by them. They usually contain one or more molecules of crystal water.

Hydrated Salt :-

A hydrated salt is a crystalline salt that is associated with a certain number of water molecules. Hydrated salts occur naturally all over the globe i.e. in freshwater bodies, groundwater bodies, rocks, etc. Hydrated salts mostly exist in crystalline form. Hydrate salt formation takes place due to exposure of salts to air allowing the formation of bonds with water molecules in the surrounding. Give two examples of hydrated salts. Plaster of Paris (POP) and gypsum salts are two examples. Epsom salts are a very familiar example of hydrated salts.

Epsom salt's general formula is MgSO₄.7H₂O and its chemical name is Magnesium Sulphate. The human body requires certain chemicals containing salt, but it might not be possible to absorb or ingest salt-containing health products through our diets alone. Hence, people are sometimes advised to take healthy baths at places where these hydrated salts are available. It is also used as a pain reliever and healing agent. Epsom salts are beneficial for maintaining blood pressure and blood circulation and also helps in digestion.

Complex Salt:-

The salts containing one or more than one complex ions with metal at the centre are defined as complex salts.

Complex salts are different from double salts and simple salts.

Examples of complex salts are as follows:-

Potassium ferricyanide [K₃Fe(CN)₆]

Potassium argentocyanide KAg(CN)₂

Complex salts are unable to dissociate completely into ions. When potassium ferricyanide is dissolved in water it dissociates into 4K⁺ and [fe(CN)₆]^- leading to formation of five ions.

Also, students can refer,

• NCERT solutions for Class 10 Science Chapter 2 Acids, Bases and Salts
• NCERT Exemplar Class 10 Chemistry Solutions Chapter 2 Acids, Bases and Salts

• NCERT notes Class 10 Chemistry Chapter 2 Acids, Bases and Salts

Difference between Complex salts and double salts :-

1. Combination of two different salts leads to formation of double salt compounds.

Whereas a chemical compound with a central metal atom forming bonds with the ligands surrounding it are called a complex salt compound.

2. Double salt consists of two salt compounds and complex salts contain one or more than one complex ion.

3. Complex salts are not capable of dissociating completely into ions but double salt compounds can completely dissociate into ions.

4. Complex ions are hard to analyze but it is much easier to analyze the ions produced due to the dissociation of double salt compounds.

5. Double salts lack coordinate bonds but complex salts consist of coordinate bonds between centrally placed metal atoms and the ligands surrounding.

6. Double salts tend to lose their identity in solution but complex salts can retain their identity.

Also check-

• NCERT Exemplar Class 11th Chemistry Solutions
• NCERT Exemplar Class 12th Chemistry Solutions
• NCERT Exemplar Solutions for All Subjects

NCERT Chemistry Notes:

• NCERT Notes Class 11th Chemistry
• NCERT Notes Class 12th Chemistry
• NCERT Notes For All Subjects