Ammonium chloride is also a sublimable solid. Give a reason why sublimation of ammonium chloride involves a physical and a chemical change.

Important Questions on Physical & Chemical Changes

MEDIUM

7th ICSE

IMPORTANT

Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 9

State why addition of sodium chloride to water is considered a physical change, while addition of dilute sulphuric acid to zinc is considered a chemical change.

MEDIUM

7th ICSE

IMPORTANT

Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 10

Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
Are any new products formed during the above process. (Yes / No)

MEDIUM

7th ICSE

IMPORTANT

Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 10

Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
Can the change be reversed or is it irreversible?

MEDIUM

7th ICSE

IMPORTANT

Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 10

Photosynthesis is a natural process by which green plants manufacture food in the presence of sunlight.
State the conclusions which can be drawn, to represent photosynthesis as a physical or a chemical change.

HARD

7th ICSE

IMPORTANT

Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 11

Give reasons why- separation of mixture e.g. iron from a mixture of iron & sulphur is a physical change, but heating a mixture of iron & sulphur is considered a chemical change.

MEDIUM

7th ICSE

IMPORTANT

Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>EXERCISE>Q 12

Explain in brief the involvement of energy in physical & chemical changes.

EASY

7th ICSE

IMPORTANT

Simplified Chemistry>Chapter 2 - Physical & Chemical Changes>OBJECTIVE TYPE QUESTIONS>Q 2

Desirable changes are meaningful, while undesirable changes are unfavourable.

EASY

7th ICSE