Chemical Changes

Q.

A colour change does not necessarily indicate a chemical reaction.

1. True
2. False

Q.

What do you mean by chemical change and chemical reaction?Explain with suitable examples.

Q. Breaking of pencil is a physical change.

1. True
2. False

Q. Burning of wood is a physical change.

1. False
2. True

Q. In a chemical reaction the undergo chemical changes to form new .

1. products
2. reactants
3. acids
4. catalysts

Q. Match the correct pairs.

1. 
2. 
3. 
4. 
5. 
6. 

Q. Melting of ice is a physical change.

1. False
2. True

Q. What will be $\text{A+B+C}$ if the following reaction is balanced?

${\text{AFeCl}}_3\text{(aq)}+\text{BMgO}\text{(s)}\to {\text{Fe}}_2{\text{O}}_3\text{(s)}+{\text{CMgCl}}_2\text{(aq)}$

1. 8
2. 10
3. 9
4. 7

Q. Which of the following are physical changes?

1. Melting of ice
2. Burning of wood
3. Clouds formation
4. Rusting of iron
5. Melting of wax
6. Tearing of paper
7. Boiling of water
8. Cooling of water

Q. Digestion of food is a physical change.

1. True
2. False

Q. Which of the following are the examples of a chemical reaction?

1. Rusting of iron
2. Conversion of steam to liquid water
3. Cutting of wood
4. Conversion of paper to paper plane