Exploring Substances Acidic Basic and Neutral Class 7 Long Question Answer
hardExploring Substances Acidic Basic and Neutral Class 7 Long Question Answer
Exploring Substances Acidic Basic and Neutral Class 7 Long Question Answer
Question 1.
What is the importance of understanding the properties of acidic, basic, and neutral substances in daily life?
Answer:
Understanding the properties of acidic, basic, and neutral substances is important in daily life for various reasons. It helps in safe cooking and food preparation, as knowing the acidic or basic nature of ingredients can affect taste and safety. It is also crucial in cleaning, as different cleaning agents have specific acidic or basic levels that determine their effectiveness.
Additionally, understanding these properties aids in gardening and agriculture, where soil acidic or basic level can significantly impact plant growth. Lastly, it is essential for environmental awareness, as the acidic or basic nature of water bodies affects aquatic ecosystems.
Question 2.
Explain the role of natural indicators in identifying acidic, basic, and neutral substances. Give examples of at least three natural indicators and describe their colour changes in different solutions.
Answer:
Natural indicators are substances derived from plants that help identify whether a substance is acidic, basic, or neutral.
- Turmeric: It remains yellow in acidic and neutral solutions but turns reddish-brown in basic solutions.
- Red cabbage juice: Turns red in acidic solutions, green in basic, and purple in neutral.
- Red rose extract: Turns red in acidic, green in basic, and shows no change in neutral solutions.
These indicators are useful in everyday life and are safer alternatives to synthetic indicators.
Question 3.
Describe the process and importance of neutralisation with examples from daily life. What are the products formed during a neutralisation reaction?
Answer:
Neutralisation is a chemical reaction where an acid reacts with a base to form salt, water and heat. This reaction helps balance the acidic or basic nature of substances.
Examples from daily life:
- Ant bite: Formic acid from the bite is neutralised by applying moist baking soda (a base).
- Indigestion: Excess stomach acid is neutralised by antacids like cold milk.
- Soil treatment: Acidic or basic soil is neutralised to make suitable for crops.
- Products formed: Salt and water.
- Cleaning: To neutralise mouth acid brushing of toothpaste protect our teeth from decay.