What is a Neutralisation Reaction?
When an acid and a base react together to form salt and water as the products of their chemical reaction, the process is termed a neutralisation reaction. For example, hydrogen ions from the acid combine with hydroxide ions of the base to form water. Strong acid and solid base neutralisation products have a pH equal to 7. Neutralising a strong acid and a weak base will have a product with 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. Since 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 reaction is given by:
acid + base → water + salt
Neutralisation plays an extremely important role in our daily life. Let’s find out.
Examples of Neutralisation Reaction
Acid + Base ---> H2O + Salt
H+Cl (acid)+ NaOH- (base) ---> H2O + NaCl (salt)
H+NO3 (acid) + NaOH- (base) ---> H2O + NaNO2(salt)
The Importance of Neutralisation Reaction in Daily Life
Let us look at some common neutralisation reactions that we experience on a daily basis and understand the importance of neutralisation reactions in our daily life.
Indigestion
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 in our stomach.
Ant Sting
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.
Tooth Decay
When we eat food, the food molecules get decomposed by the action of the microorganism present in the mouth. This results in the formation of acid. This acid is majorly responsible for 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. As a result, the harmful effect of the acid is neutralised, and it stops tooth decay.
Shiny Hair Due to Conditioner
Our hair becomes rough after a shampoo, but it becomes 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.
Monitor pH of the Soil
Plants grow in soil that has a particular pH value. Plants cannot grow on soil that 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 in the soil.
Other Examples of Neutralisation Reaction in Daily Life
In wastewater treatment, this method is used to reduce the damage caused by the effluents.
A neutralisation reaction 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 of 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 neutralise 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.
Example Questions
1. Give examples of strong acids and strong bases.
Ans: 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 sulphuric acid.
Strong Bases: Lithium hydroxide, calcium hydroxide, sodium hydroxide, potassium hydroxide, caesium hydroxide etc.
FAQs on Importance of Neutralization Reaction in Daily Life
1. What is the importance of a neutralization reaction in daily life?
Neutralization reactions are essential in daily life because they help manage and control acidity or basicity in many common situations. This includes using antacids to relieve stomach indigestion, applying baking soda to an insect sting, improving soil quality in agriculture, and maintaining oral hygiene with toothpaste to prevent tooth decay.
2. What are the two main products formed in a neutralization reaction?
In a neutralization reaction, an acid chemically reacts with a base to produce two distinct products: a salt and water. The hydrogen ions (H+) from the acid and hydroxide ions (OH-) from the base combine to form water, which is neutral, while the remaining ions form the salt.
3. How does using an antacid for indigestion demonstrate a neutralization reaction?
The stomach produces hydrochloric acid to digest food. Excess acid can cause pain and discomfort, a condition known as acidity or indigestion. Antacids contain a mild base, such as magnesium hydroxide. When consumed, this base reacts with and neutralizes the excess stomach acid, providing quick relief.
4. Why is applying baking soda on an ant sting a common remedy?
An ant sting is painful because the ant injects formic acid into the skin. Baking soda (sodium bicarbonate) is a mild base. By applying a paste of baking soda and water to the affected area, a neutralization reaction occurs. This neutralizes the formic acid, which helps to alleviate the pain and irritation.
5. Does a neutralization reaction always result in a completely neutral solution (pH 7)?
No, this is a common misconception. A perfectly neutral solution (pH = 7) is formed only when a strong acid reacts with a strong base. The final pH depends on the strength of the reactants:
- A strong acid and a weak base will produce an acidic salt (pH < 7).
- A weak acid and a strong base will produce a basic salt (pH > 7).
The term 'neutralization' refers to the reaction process itself, not always a neutral outcome.
6. How is neutralization important for agriculture and farming?
Soil can become too acidic due to factors like acid rain or certain fertilisers, which prevents plants from absorbing essential nutrients. Farmers use neutralization to correct this. They add basic substances like powdered lime (calcium oxide) or wood ash to the soil. These bases react with the excess acid, neutralizing the soil and restoring a pH level suitable for healthy crop growth.
7. How does toothpaste use neutralization to protect our teeth?
When we eat, bacteria in our mouth break down sugar and produce acids. This acid can erode tooth enamel, leading to tooth decay. Most toothpastes are formulated to be alkaline (basic). Brushing with toothpaste neutralizes the acids in the mouth, protecting the enamel and helping to prevent cavities.
8. What is the difference between reducing acidity with neutralization versus simply adding water (dilution)?
While both methods reduce the strength of an acid, they work differently. Dilution (adding water) decreases the acid's concentration but does not eliminate it; the total amount of acid remains. In contrast, neutralization is a chemical reaction that converts the acid into harmless substances (salt and water), effectively eliminating its acidic properties. Neutralization is a more permanent and targeted solution for controlling pH.
9. Besides our homes, where else are neutralization reactions critically important?
Neutralization is crucial in many large-scale industrial and environmental applications. Key examples include:
- Wastewater Treatment: Industrial waste (effluents) is often acidic or basic. It must be neutralized before being safely released into rivers or lakes.
- Pollution Control: Power plants treat acidic exhaust gases like sulphur dioxide with basic compounds like lime to prevent acid rain.
- Manufacturing: The production of soap, paper, and fertilisers relies on carefully controlled neutralization reactions to achieve the desired products.
