What is Neutralisation Reaction?

S6-SA4-0038

Grade Level:

Class 10

AI/ML, Physics, Biotechnology, Space Technology, Chemistry, Engineering, Medicine

Definition

What is it?

A neutralisation reaction is a chemical reaction where an acid and a base react with each other to form salt and water. This reaction essentially 'cancels out' the acidic and basic properties, making the resulting solution neutral or close to neutral.

Simple Example

Quick Example

Imagine you've eaten too many spicy pakoras and have acidity (too much acid in your stomach). To feel better, you might take an antacid like Eno or Gelusil. These antacids are bases, and they react with the excess acid in your stomach to neutralise it, giving you relief.

Worked Example

Step-by-Step

Let's say you have a beaker with some hydrochloric acid (HCl), which is a strong acid. You want to neutralise it using sodium hydroxide (NaOH), a strong base.---Step 1: Write down the reactants: HCl (acid) + NaOH (base).---Step 2: Predict the products. An acid and a base always produce salt and water. In this case, the salt will be sodium chloride (NaCl) and the water will be H2O.---Step 3: Write the balanced chemical equation: HCl + NaOH → NaCl + H2O.---Step 4: Observe the properties. Hydrochloric acid is corrosive, and sodium hydroxide is also corrosive. However, sodium chloride (common table salt) is harmless (in small amounts), and water is neutral. The acidic and basic properties have been neutralised.---Answer: The reaction HCl + NaOH → NaCl + H2O represents a neutralisation reaction, forming salt and water.

Why It Matters

Neutralisation reactions are crucial in fields like medicine for treating acidity, in environmental science for managing soil pH, and in chemical engineering for waste treatment. Doctors use it to formulate medicines, and environmentalists use it to ensure our water and soil are safe.

Common Mistakes

MISTAKE: Thinking neutralisation always results in a perfectly neutral solution (pH 7). | CORRECTION: While the goal is neutralisation, the resulting salt solution might be slightly acidic or basic depending on the strength of the acid and base used (e.g., strong acid + weak base will result in an acidic salt solution).

MISTAKE: Forgetting that water is always a product of neutralisation. | CORRECTION: Always remember that an acid reacting with a base produces both a salt AND water. It's not just about forming the salt.

MISTAKE: Confusing neutralisation with dilution. | CORRECTION: Dilution just adds water to reduce concentration; neutralisation involves a chemical reaction between an acid and a base to form new substances (salt and water).

Practice Questions

Try It Yourself

QUESTION: What are the two main products of a neutralisation reaction? | ANSWER: Salt and Water

QUESTION: Write the balanced chemical equation for the neutralisation reaction between sulfuric acid (H2SO4) and potassium hydroxide (KOH). | ANSWER: H2SO4 + 2KOH → K2SO4 + 2H2O

QUESTION: A farmer finds his soil is too acidic for growing crops. What type of substance should he add to the soil to neutralise it? Give an example. | ANSWER: He should add a basic substance. Examples include slaked lime (calcium hydroxide) or quicklime (calcium oxide).

MCQ

Quick Quiz

Which of the following is an example of a neutralisation reaction?

Adding water to lemon juice

Burning wood to produce ash

Mixing vinegar with baking soda

Dissolving salt in water

The Correct Answer Is:

Mixing vinegar (acetic acid) with baking soda (sodium bicarbonate, a base) results in a neutralisation reaction, producing salt, water, and carbon dioxide. The other options are dilution, combustion, and dissolution, respectively.

Real World Connection

In the Real World

In daily life, neutralisation helps us manage waste. For instance, industrial factories often produce acidic or basic wastewater. Before releasing it into rivers, they use neutralisation reactions to bring the pH of the water close to neutral, protecting aquatic life and preventing pollution. This is a crucial part of environmental compliance in industries across India.

Key Vocabulary

Key Terms

ACID: A substance that releases H+ ions in water, typically having a pH less than 7 | BASE: A substance that releases OH- ions in water or accepts H+ ions, typically having a pH greater than 7 | SALT: An ionic compound formed from the reaction of an acid and a base | pH SCALE: A scale (0-14) used to measure how acidic or basic a substance is, with 7 being neutral | INDICATOR: A substance that changes color in the presence of an acid or a base

What's Next

What to Learn Next

Now that you understand neutralisation, you're ready to explore the concept of pH in more detail, including strong and weak acids/bases. This will help you predict the exact nature of the salt solutions formed and their applications in various fields.