Question

1.growth of plant 2.rusting of iron 3.mixing of iron filling and sand 4.cooking of food 5.digestion of food 6.freezing of water 7.burning of candle which of the following is a chemical change ? please answer fast​

Answer 1

Answer:

1,2,4,5,7 are chemical change

Answer 2

Answer ::

★ Which of the following is a chemical change?

1. growth of plant ✓
2. rusting of iron ✓
3. mixing of iron filling and sand
4. cooking of food ✓
5. digestion of food ✓
6. freezing of water
7. burning of candle ✓

Explanation ::-

1. Growth of plant ::

• Chemical change

Reason ::

• New substances is formed.
• Irreversible change.
• Energy is either gained or evolved.
• Change in mas occured.
• The change is permanent.

2. Rusting of iron ::

• Chemical change

Reason ::

• New substances is formed.
• Irreversible change.
• Energy is either gained or evolved.
• Change in mas occured.
• The change is permanent.

3. Mixing of iron filling and sand ::

• Not a chemical change [ physical change ]

Reason ::

• No new substances is formed.
• Reversible change.
• Energy is not either gained or evolved.
• Change in mas didn't took place.
• The change is temporary.

4. Cooking of food ::

• Chemical change

Reason ::

• New substances is formed.
• Irreversible change.
• Energy is either gained or evolved.
• Change in mas occured.
• The change is permanent.

5. Digestion of food

• Chemical change

Reason ::

• New substances is formed.
• Irreversible change.
• Energy is either gained or evolved.
• Change in mas occured.
• The change is permanent.

6. Freezing of water

• Not a chemical change [ physical change ]

Reason ::

• No new substances is formed.
• Reversible change.
• Energy is not either gained or evolved.
• Change in mas didn't took place.
• The change is temporary.

7. Burning of candle

• Not a chemical change [ physical change ]

Reason ::

• No new substances is formed.
• Reversible change.
• Energy is not either gained or evolved.
• Change in mas didn't took place.
• The change is temporary.

More Information

$\bf{Physical \: change}$

Physical change is a temporary change in which no new substance is formed and it can be reversed by simple physical means.

Some examples ::

• ringing of an electric bulb
• sublimation
• evaporation of water
• dissolution of sodium chloride in water, and many more.

$\bf{Chemical \: change}$

Chemical change is a permanent change in which new substance is formed and cannot be reversed by simple physical means.

Some examples ::

• cooking of vegetables
• burning of phosphorus
• cooking of coal
• breathing by humans, and many more.