When an acid and a base react together to form salt and water as the products of their chemical reaction, the process is termed as a neutralisation reaction. Hydrogen ions from the acid combine with hydroxide ions of the base to form water. Strong acid and solid base neutralisation have a pH equal to 7. Neutralising a strong acid and a weak base will have a pH of less than 7, and conversely, the resulting pH will be greater than 7 when a strong base neutralises a weak acid. When a solution is neutralised, it means salts are formed out of the same acid and base weights. The amount of acid required is the amount that would give a one-mole proton (H+), and the amount of base needed is the amount that would give one (OH-) mole. Because salts are formed from neutralisation reactions with equivalent acid and base in terms of weight concentrations: N parts of acid will always neutralise with N parts of the base. Neutralisation in our daily life plays an extremely important role. Let’s find out.
Example of a neutralization reaction:
acid + base → water + salt
Acid + Base ---> H2O + Salt
H+Cl (acid)+ NaOH- (base) ---> H2O + NaCl (salt)
H+NO3 (acid) + NaOH- (base) ---> H2O + NaNO2(salt)
Let us look at some common neutralisation reactions in daily life that we experience on a daily basis and understand the importance of neutralisation reactions in our daily life.
Too much acid is produced inside the stomach during indigestion which results in stomach disorder or acidity. We take bases such as magnesium milk which contains magnesium hydroxide to retrieve the pain. Taking a base neutralises the excess acid effect.
The ant sting can be painful as it has formic acid. We can neutralise this acid effect and relieve the pain caused by the sting by using moist baking soda which is basic in nature.
When we eat food, the food molecules get decomposed by the action of the microorganisms present in the mouth. This further results in the formation of acid. This acid is majorly responsible for the tooth decay. Toothpaste is generally made by alkaline substances to make its nature basic. So, when you brush your teeth, this basic nature of the toothpaste reacts with the acid produced by the microorganisms, which causes tooth decay. As a result, the harmful effect of the acid is neutralised, and it stops the tooth decay.
Our hair is rough after a shampoo, but it gets shiny after using a conditioner. This happens because shampoo is basic in nature, and the conditioner is acidic. So, the conditioner neutralises its effect, and the hair becomes shiny.
Plants grow on a soil which has a particular pH value. Plants cannot grow on soil which has an acidic composition. So, to neutralise its effect bases are added to the soil. Compounds such as limestone, powdered lime, and also burnt wood ashes are added to the soil to make its pH less acidic. This technique helps in controlling the pH of the soil by neutralising the effect of acids and bases in the soil.
In wastewater treatment, this method is used to reduce the damage caused by the effluents. This is a great example of neutralisation reaction examples in real life.
Neutralisation is also used in the antacid tablet manufacturing process.
The power stations and industries emit acidic gases such as sulphur dioxide in the air as a by-product to several chemical processes taking place during the operations. These gases are harmful to the body if inhaled and also harmful to the environment. As a result, these gases are treated with lime (CaO - calcium oxide) in order to get neutralised and reduce their harmful effects.
In the industries, the coagulation of latex is prevented by the use of ammonia, NH3. The bacteria in the latex produces acid, whose effect is neutralised by the basic nature of ammonia.
Q1 Give Examples of Strong Acids and Strong Bases.
Answer Some examples of strong acids and strong bases are as follows:
Strong Acids: hydrochloric acid, hydroiodic acid, nitric acid, chloric acid, hydrobromic acid, perchloric acid, and sulfuric acid.
Strong Bases: lithium hydroxide, calcium hydroxide, sodium hydroxide, potassium hydroxide, caesium hydroxide etc.
1. Why is the Reaction Between Acids and Bases Termed As Neutralisation?
The reaction between acid and base is known as neutralisation because of the following reasons:
The formation of hydrogen ions and hydroxide ions takes place during this reaction. This process is known as ionisation which results in the formation of water. The water is a by-product and is neutral in nature.
Another product formed is the salt of the reactants. The acid and base form a salt as the product. This is formed as a result of the ionisation process. The charges in the salt are equal and opposite in nature and are held together by electrostatic forces of attraction. So, the salt formed is also neutral in nature.
However, neutral salts are only formed in these mentioned cases: strong acid reacts with a strong base, and weak acid reacts with a weak base.
If strong acid reacts with a weak base, acidic salt will be formed. If weak acid reacts with a strong base, basic salt will be formed. These two cases do not produce a neutral salt.
2. What are the Uses of Acids and Bases in Daily Life?
HCl - Hydrochloric acid: used to produce glucose from corn starch
Carbonic acid: used in aerated drinks or beverages
Sulphuric acid: used in car batteries
Nitric acid: manufacturing of fertilisers, drugs, explosives, and dyes
Sodium hydroxide: used in the production of soaps, paper, and synthetic fibres
Magnesium hydroxide: used as an antacid to neutralise the acid in the stomach
Ammonium hydroxide: manufacturing of fertilisers
Calcium hydroxide: used for manufacturing bleaching powder