Chemical Changes

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

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

Q. Breaking of pencil is a physical change.

1. True
2. False

Q. Melting of ice is a physical change.

1. False
2. True

Q. Burning of wood is a physical change.

1. False
2. True

Q. Match the correct pairs.

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

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 statement is correct?

1. Melting is a chemical change because the melted wax can again be obtained as solid wax upon cooling.

2. Burning of wax is a chemical change, as once the wax has been burnt, it cannot be obtained back in its original form.

3. Cutting of trees is a chemical change as it gives new products with different composition.

4. Combustion of fuel is a physical change as the fuel can be reobtained from the gases liberated.

Q. Which of the following is a chemical change?

1. Baking a cake
2. Melting of ice
3. Cutting fruits
4. Boiling of water

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