HARD
7th CBSE
IMPORTANT
Earn 100

Give an example of a chemical change in which a change of colour takes place.

Important Questions on Physical And Chemical Changes

HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 2 - Physical And Chemical Changes>EXERCISE>Q 5
Why do cut vegetables and fruits turn brown when exposed to air?
HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 2 - Physical And Chemical Changes>EXERCISE>Q 6
Define combustion. What type of change is it? Demonstrate with an activity.
HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 2 - Physical And Chemical Changes>EXERCISE>Q 7
Define chemical equation. Write the steps for balancing it. Explain by giving an example.
HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 2 - Physical And Chemical Changes>EXERCISE>Q 8
What type of chemical reaction takes place when a magnesium wire is burned in air?
HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 2 - Physical And Chemical Changes>EXERCISE>Q 8
What type of chemical reaction takes place when limestone is heated?
HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 2 - Physical And Chemical Changes>EXERCISE>Q 8
What type of chemical reaction takes place when silver bromide is exposed to sunlight?
HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 2 - Physical And Chemical Changes>EXERCISE>Q 8
What type of chemical reaction takes place when zinc strip is dipped into a copper sulphate solution?
 
HARD
7th CBSE
IMPORTANT
Foundation Course Chemistry>Chapter 2 - Physical And Chemical Changes>EXERCISE>Q 9
Which gas is evolved when dil. hydrochloric acid is added to calcium carbonate? How will you test the gas? Write the chemical equations involved.