HARD
7th CBSE
IMPORTANT
Earn 100

Write the chemical equation for the reaction that takes place when a magnesium ribbon is burnt in air.

Important Questions on Physical and Chemical Changes

MEDIUM
7th CBSE
IMPORTANT
CONCERT Science 7>Chapter 6 - Physical and Chemical Changes>STEP IN>Q 4
Fill in the blank to complete the sentence about the experiment.
An iron nail is dropped into a copper sulphate solution in a flask.
A green solution is seen in the flask after some time. This is a solution of _____.
MEDIUM
7th CBSE
IMPORTANT
CONCERT Science 7>Chapter 6 - Physical and Chemical Changes>STEP IN>Q 4
An iron nail is dropped into a copper sulphate solution in a flask. Fill in the blank to complete the sentence about the experiment.
A brownish coating of _____ forms on the nail.
MEDIUM
7th CBSE
IMPORTANT
CONCERT Science 7>Chapter 6 - Physical and Chemical Changes>STEP IN>Q 4
Write the chemical equation for the reaction that takes place when the iron nail is left immersed in a copper sulphate solution.
HARD
7th CBSE
IMPORTANT
CONCERT Science 7>Chapter 6 - Physical and Chemical Changes>STEP IN>Q 5

A pinch of baking soda is added to vinegar in a test tube. Answer this question on the reaction that occurs.

Write the chemical equation for the reaction.

MEDIUM
7th CBSE
IMPORTANT
CONCERT Science 7>Chapter 6 - Physical and Chemical Changes>STEP IN>Q 5

A pinch of baking soda is added to vinegar in a test tube. Answer this question on the reaction that occurs.

How can we test whether the gas produced is carbon dioxide?

MEDIUM
7th CBSE
IMPORTANT
CONCERT Science 7>Chapter 6 - Physical and Chemical Changes>STEP IN>Q 5
Write the chemical equation for the reaction used to test for carbon dioxide.
EASY
7th CBSE
IMPORTANT
CONCERT Science 7>Chapter 6 - Physical and Chemical Changes>STEP IN>Q 6
What are the conditions necessary for rusting of iron?
MEDIUM
7th CBSE
IMPORTANT
CONCERT Science 7>Chapter 6 - Physical and Chemical Changes>STEP IN>Q 6
List two ways in which rusting can be prevented.