Nitrogen Cycle

 

ACIDS, BASES AND SALTS

Hello lovely learners, today we are talking about acids, bases and salts.

These chemicals are very important in our daily lives as we used them frequently.

Things such as tomato, banana, vinegar and rain water contains acids, ash, liquid soaps, bar soaps, toothpastes also contain bases whiles common salt, chalk also contain salts.

Now let us take a closer look at these three (3) things. To begin, let us look at acids.

ACIDS

An acid is a substance that dissolves in water to produce Hydrogen ions (H⁺). It is formed when a hydrogen ion bonds with an anion apart from oxygen.

Examples includes, Hydrochloric acid (HCl), Nitric acid (HNO₃), sulfuric acid (H₂SO₄) e.t.c.

There are two (2) types of acids based on their sources. i.e organic – from plants and animal sources and inorganic – prepared in the laboratories. The table below shows some organic acids and their sources

Organic acid	Sources
Palmitic acid	Palm oil
Ethanoic acid	Beers
Acetic acid	Vinegar
Salicylic acid	Aspirin
Lactic acid	Sour milk
Ascorbic acid	Tomato and ripen fruits
Citric acid	Lemons and unripen oranges
Malic acids	Apples
Formic acid	Red ants and bees
Tartaric acid	Grapes
Uric acid	Urea

You can search online and add some other examples.

Let us look at some properties of acids. We will group them into physical and chemical properties.

Physical Properties of acids

1.       They have sour taste

2.       They are corrosive when concentrated

3.       They turn litmus and methyl orange red

4.       Conducts electricity in aqueous solutions

Chemical Properties of acids

1.       They combine with bases to form salts and water. (neutralization reaction)

Eg. Hydrochloric acids react with sodium hydroxide to form sodium chloride salt and water

2.       They react with metals  to form salts and hydrogen gas (this is called effervescence)

3.       They react with carbonates to form carbon dioxide

4.       They release heat when reacting with bases

5.       Has a pH less than 7

6.       They dissolve in water to form hydrogen ions

NB: strong acids have pH from 1 – 3 whiles weak acids have pH from 4 – 6.9

BASES

A base is a substance that dissolve in water to produce hydroxide ions (OH^-).

A base that dissolves completely in water is called an alkali.

Like acids, bases are grouped into organic and inorganic bases.

Here is a table of some weak bases

Organic Bases	Sources
Amines	Fishes
Alkaloids	Coffee beans and tobacco plants
Amino acids	Protein foods
Biological bases	Immune system cells
Caustic potash	Wood ash

 Now like acids, let us look at the physical and chemical properties of bases

Physical properties of bases

1.       They have bitter taste

2.       They are slippery

3.       Strong bases are corrosive when concentrated

4.       They turn litmus blue

5.       They turn phenolphthalein red

6.       They turn methyl orange yellow

 

Chemical properties of bases

1.       They react with acids to form water and salts

2.       They dissolve in water to produce hydroxide ions

3.       They have a pH greater than 7

4.       They produce heat when reacting with acids

5.       They react with oils or fats to form soaps (SAPONIFICATION)

6.       Can speed up chemical reactions

7.       Conducts electricity in aqueous solutions

SALTS

A salt is formed when the hydrogen ion in an acid is replaced by a metal. Eg. In HCl, we replace the H with K to form KCL (potassium chloride is a salt). They are typically crystalline solids.

Like acids and bases, salts are corrosive when concentrated. They have a pH of 7 and is neutral to all pH indicators (litmus, methyl orange and phenolphthalein).

Some salts may have a sharp taste whiles others are tasteless.

Example of salts includes Sodium chloride (NaCl), Potassium Chloride (KCl), Ammonium nitrate (NH₄NO₃) etc.

Uses of acids, bases and salts

1.       ACIDS

a.       Acids are used in the manufacturing chemicals such as plastics and fertilizers

b.      They are also used in metal processing

c.       It is used in the textile industry (for dyeing and printing)

d.      Water treatment such as pH adjustments and disinfections

e.      It is used in food preservations, flavor enhancements and beverage productions

f.        It is used in yeast activation for baking

g.       It is for making medicines such as antacids, antibiotics, vitamin synthesis and medical research.

h.      Some acids are used for water purification, medical research and others.

2.       BASES

a.       It helps in the production of soaps and detergents (NaOH)

b.      It is used in paper manufacturing, textile industry for dyeing, printing and finishing

c.       Water treatments

d.      It is also used for food processing, baking and beverage production

e.      It is used to make cleaning products for households.

f.        Battery manufacturing (KOH)

g.       For making antacids (Mg(OH)₂).

3.       SALTS

a.       They are used to make antiseptics, mouth washes and other medicinal products.

b.      They are also used to make inhalers and nebulizers.

c.       Helps in waste recycling

d.      It helps in microbial degradation of pollutants

e.      It is used in food preservation

f.        Helps in making detergents and cleaning agents for households

g.       For making fertilizers

h.      For water treatments and managements.

Always remember to use protective clothing when using acids, bases and salts.

Do not add any substance to acids, but add acids slowly to other substances whiles stirring to distribute heat uniformly.

This is the end of our lesson today. Make sure to go through all these lessons. There are other useful topics on science, mathematics and computing. Feel free to contact us on topics you wish to learn more about.