HARD
7th ICSE
IMPORTANT
Earn 100

Give the main experimental points only to demonstrate that Candle gains weight on burning.

Important Questions on Air & Atmosphere

EASY
7th ICSE
IMPORTANT

Give reasons for the following: Patients suffering from lung problems are kept in an oxygen tent.

EASY
7th ICSE
IMPORTANT

Give reasons for the following:

Oxygen finds utility in welding & cutting of metals.

HARD
7th ICSE
IMPORTANT

Match the following.

List I List II
1. The constituent of air which is around 0.02%. A. Nitrogen
2. The constituent of air which is inert or unreactive. B. Oxygen
3. The constituent of air which is non-combustible, but supports combustion. C. Sulphur dioxide
4. A pollutant in air responsible for acid rain. D. Carbon dioxide
 
5. The main rare gas present in air. E. Argon
EASY
7th ICSE
IMPORTANT

Give reasons for the following:

Acid rain has caused damage to heritage structures such as the Taj Mahal.

EASY
7th ICSE
IMPORTANT

Give reasons for the following:

In the laboratory preparation of oxygen from potassium chlorate - manganese dioxide is added to the reactant.

EASY
7th ICSE
IMPORTANT

Give reasons for the following:

Oxygen gas does not affect moist blue litmus paper, but carbon dioxide turns it slightly pink.

EASY
7th ICSE
IMPORTANT

Give reasons for the following:

Oxidation of sulphur results in a product which turns moist blue litmus red.

EASY
7th ICSE
IMPORTANT

Give reasons for the following:

Combustion and respiration show similarity.