Physical and Chemical Changes Worksheet-3

Physical and Chemical Changes Worksheet-3

1. Which of the following is an incorrect statement?

(a) Burning of coal is a chemical change

(b) Rusting of iron is due to formation of hydrated ferric oxide

(c) The fizz that comes out when a soda bottle is opened is due to a chemical change

(d) Respiration is a chemical process

2. When an iron nail is dipped in copper sulphate (blue vitrol) solution, it turns green due to the formation of:

(a) Iron sulphate

(b) Mixture of copper & iron

(c) Deposition of copper on iron nail

(d) None of these

3. If the chemical properties of a substance remain unchanged and the appearance or shape of a substance changes, it is called a

(a) Physical change

(b) Chemical change

(c) Neither a physical nor chemical change

(d) Both a physical and chemical change

4. Which of the following characteristic best describes a physical change?

(a) Composition changes

(b) Composition remains the same

(c) State of the matter remains same

(d) Loss of mass

5. What is Y?

(a) MgOH

(b) Mg₂OH

(c) Mg(OH)₂

(d) None of these

6. What does Z indicate?

(a) Red litmus does not show change in colour

(b) Red litmus turns blue

(c) Red litmus turns yellow

(d) The solution becomes colourless

7. What happens when we cut an apple and keep the slices exposed to air for sometime?

(a) The colour of the cut surface becomes brown

(b) The change in colour is due to chemical reaction between air and enzymes

(c) Both The colour of the cut surface becomes brown & The change in colour is due to chemical reaction between air and enzymes

(d) None of these

8. The shipping industry has to bear huge monetary losses due to rusting of ships. What are the causes leading to this?

(a) The body of the ship is always in contact with water.

(b) The air around is very humid.

(c) The salt in water speeds up the process of rusting.

(d) All of these

9. What happens when steam gets condensed?

(a) A new substance is formed

(b) No new substance is formed

(c) Water gets converted from vapour phase to liquid phase

(d) Both No new substance is formed & Water gets converted from vapour phase to liquid phase

10. Read the given statements and select the correct option.

Statement I: Breaking of a bone china plate is a chemical change.

Statement II: When a bone china plate breaks, the pieces cannot be joined to get back the original plate.

(a) Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1.

(b) Both statement 1 and 2 are true but statement 2 is not the correct explanation of statement 1.

(c) Statement 1 is false and statement 2 is true.

(d) Both statements 1 and 2 are false.

Answer Key:

1. (c)
2. (a)
3. (a)
4. (b)
5. (c)
6. (b)
7. (c)
8. (d)
9. (d)
10. (c)