Class Seven Science Acid-bases and salts NCERT Solutions
Chapter 5: Acids, Bases and Salts
Additional Questions with Answers
Fill in the blanks:
(1) Those substances which are neither acidic
nor basic in nature are called _____.
(2) Acid + Base _____ + water
(3) NaOH + HCl _____ + H2O
(4) Turmeric turns in basic solution.
(5) When an acid is mixed with a base, a reaction takes place.
1. neutral substances
State True or False:
1. Litmus paper is the most commonly used indicator.
2. China rose indicator turns acidic solutions blue.
3. HCl is present in our stomach.
4. Lemon juice is basic in nature.
5. Formic acid is present in vinegar.
1. True 2. False 3. True 4. False
Match the Column A with Column B
Column A Column B
.i C ii d iii b iv a.
Very Short Answer Type Questions
1. Give two examples of ascorbic acid.
Answer Amla and citrus fruits like oranges etc. are two examples of ascorbic acid.
2. What important role does hydrochloric acid present in our stomach plays?
Answer Hydrochloric acid helps in the digestion of food.
3. What is the nature of lime water?
Answer Lime water is basic in nature.
4. Define acid with some examples.
Answer A substance that reacts with a base to form salt and water is called acid. Curd, lemon juice, oranges, grapes etc. contains acid.
5. What are neutral substances?
Answer Substances that are neither acidic nor basic are called neutral.
6. What is meant by the term ‘indicators’?
Answer Solutions of substances that show different colour in acidic, basic and neutral solutions are called indicators.
7. Name the medicine which is used to get relief from excessive hydrochloric acid in our stomach.
Answer A medicine made of milk of magnesia is taken to neutralize the effect of excessive hydrochloric acid in our stomach.