TRY!! CHEMISTRY - AIR AND ATMOSPHERE - MULTIPLE CHOICE QUESTIONS - EX 5.1

🌟 Atmosphere Adventure: Mastery Quiz (Exercise 5.1) Instructions: Choose the best answer for each question based on your studies. 

🧪 Unit Test 5.1

1. Oxygen is necessary for respiration and ______:

Photosynthesis Combustion Evaporation Condensation

2. The envelope of air surrounding the earth is known as ______:

Exosphere Atmosphere Biosphere Hydrosphere

3. The life supporting constituent of air is ______:

Nitrogen Oxygen Carbon Dioxide Argon

4. Products of combustion turn anhydrous copper sulphate ______: 

Yellow Blue Pink Colorless

5. When clear limewater is exposed to air, it eventually turns ______:

Milky Pink Blue Green

6. What are the REAL products of the combustion of a fuel?

Nitrogen and Water Vapour Carbon Dioxide and Water Vapour Oxygen and Heat only Ash and Nitrogen

7. How is Coal primarily used as a fuel? As an Industrial Fuel

As a Household Fuel In wick lamps In aircraft engines

8. What is the true purpose of LPG in homes?

To extinguish fires As a combustible household fuel To purify the air As a coolant in fridges

9. Which gas turns limewater milky? Nitrogen

Carbon Dioxide Helium Oxygen

10. What is the percentage of Oxygen in the air? 78.3% 21% 0.03% 1%

🧪 Study Check: Key Facts from the Text

Air Composition: Air is about 78.3% Nitrogen and 21% Oxygen by volume.

Limewater Test: Limewater is used to detect Carbon Dioxide. 

Copper Sulphate Test: Anhydrous copper sulphate (white) turns blue when it touches water vapour. 

Combustion Equation: When fuel burns, it reacts with Oxygen to produce Carbon Dioxide, Water Vapour, and Heat.

Household Fuels: Common fuels include LPG (Liquefied Petroleum Gas), CNG (Compressed Natural Gas), and Kerosene oil.