NCERT Solutions Class 7 Science Chapter 2 Exploring Substances: Acidic, Basic, and Neutral

Every day we encounter substances: some are sour like lemon, some are bitter like soap, and some are neutral like water. In NCERT Solutions Class 7 Science Chapter 2 (Acids, Bases and Salts), students learn about acids, bases, and neutral substances; which explore what these substances do and how they behave in the real world.

NCERT Solutions Class 7 Science Chapter 2 teaches students how to use natural indicators to identify substances and teach them about chemical reactions in acids and bases; explaining reactions using neutralization. These solutions will help guide your learning journey in exploring acids and bases, whether you explore their chemical nature to prepare for your exams or just out of interest! 

1.0NCERT Solutions Class 7 Science Chapter 2 – Exploring Substances: Acidic, Basic, and Neutral – Download PDF

Download the free PDF of NCERT Solutions for Class 7 Science Chapter 2 from below:

2.0Key Concepts in Chapter 2 : Exploring Substances: Acidic, Basic, and Neutral

Acids

• Acids are typically sour in flavor, and litmus that is blue would turn red when acid is added.
• People will consume acids every day like lemon, vinegar and curd, and many chemicals that are also acidic. There are naturally occurring acids (like citric acid in orange, for instance) and there are acids that are manufactured in a laboratory (like hydrochloric acid).

Bases

• Bases tend to be bitter in flavor, and feel soapy in contact.
• Red litmus will turn blue.
• Common bases are soap, baking soda and limewater.

Natural Indicators and How to Use Them

• Litmus (from lichens) - red in acid, blue in a base.
• Turmeric - turns red in a base; yellow in an acid.
• China rose (hibiscus) - light pink in an acid; green in a base.

These allow us to establish the nature of unknown materials for chemical analysis.

Neutral Substances

• Neutral substances are neither acidic or basic.
• They do not change the color of any indicator.

There are known examples like water, sugar solution, or salt solution (under certain circumstances).

Neutralization Reaction

When an acid reacts with a base, the two substances will "neutralize" one another and produce salt and water: 

Acid + Base → Salt + Water.

We use this reaction in:

• Antacid tablets that neutralize gastric acid for heartburn
• To balance out bee sting or wasp stings
• Land farming to neutralize soils
• Wastewater

Everyday Uses and Scientific Applications

The science of acids, bases, and neutralization goes much beyond the lab! Acids and bases are found in your everyday life and professions from healthcare to farming:

Healthcare: Antacid medications neutralize excessive stomach acid to relieve symptoms of acidity. 

Agriculture: Farmers apply lime to acidic soil to bring back the soil fertility so they can grow crops. 

Everyday Uses: Natural indicators, such as turmeric or red cabbage, can test the chemical nature of household chemicals or food.

Environmental Safety: Neutralization is also significant for the treatment of industrial waste by safely disposing of harmful acids or bases.

It is clear that acids and bases exist in many real-life applications and chemistry exists as a way to help support human health, sustainable farming, and environmental protection.

Fostering Scientific Inquiry and Hands-On Engagement

This chapter will motivate students to consider science through observation and experimentation!

• Why did turmeric turn red after being touched by the soap?
• How does vinegar help with a wasp sting?
• What happened when lemon juice was mixed with baking soda?

As these questions come to mind, students will be encouraged to test, critically analyze, and make deductions from their observations. The experiential emphasis within this chapter is one of the most memorable and thought-provoking topics from the Class 7 Science syllabus.

3.0Key Features of NCERT Solutions – Chapter 2: Exploring Substances: Acidic, Basic, and Neutral

1. Provide a solid conceptual foundation:

The NCERT Solutions centers on important concepts such as acids, bases, indicators and neutralisation while providing as clear and rational descriptions as can be achieved. This gives students a pretty reliable grasp as the underlying principles of elementary chemistry.

2. Develop observation and reasoning abilities:

These solutions are based on developing reasoning as opposed to simply providing answers to the problem. By understanding why associated with a result, students will develop the type of critical thinking that can lead to developing analytical skills, which are crucial in science and science learning.

3. Present aspects of the scientific method and scientific inquiry:

These solutions expose students to elements of the scientific method—testing substances, observing color changes, and interpreting reactions based on indicators, both natural and synthetic. This helps students become familiar with aspects of the scientific method, in a fun, meaningful and visceral way.

4. Relate chemistry concepts to students' lived experiences:

This chapter connects scientific theory to experiences in daily life—whether it is taking an antacid after eating too much, treating soil in agriculture, or soaps cleaning up a turmeric stain on a shirt. This chapter develops a real-life connection for students to what they are learning.

5. Develop confidence in understanding chemistry:

These solutions walk learners through the questions in the textbook in a step-by-step manner and the clarity will help students eliminate the confusion when approaching problems. By establishing such clear expectations, learners will be able to tackle both theory and application-based questions.