Coal and Petroleum of Class 8

Name the main components of air

Solution:

Explanation:-

• Air is a mixture of gasses which contain lot of components but the main components are:-

1)Nitrogen(78%)

2) Oxygen (20.5%)

3)Argon (0.91%)

4)Carbon dioxide(0.003%)

Final Answer:-

Nitrogen, Oxygen, Argan and Carbon dioxide are the main components of air

State full form of LPG and CNG

How are the two differ in their composition?

Solution:

Explanation:-

• LPG- Liquefied Petroleum Gas.
• CNG- Compressed Natural Gas.
• CNG  contains  93.305% methane (CH ₄ )  and other gasses like carbon dioxide ,nitrogen and traces of ethane and propane.
• LPG contains primarily  mixture of   Propane (C ₃ H ₈ ) and butane  (C ₄ H ₁₀ ).

like-  100% propane or 60% propane and 40% butane. Its composition depends on region and country.

Final Answer:-

Propane and butane is the main component of LPG and Methane is the main component of CNG .

Name a non - metal which is good conductor of electricity

Solution:

Explanation: Non-metals are a bad conductor of electricity i.e. they do not conduct electricity.

But graphite- an isotope of carbon conducts electricity.

Carbon is a non-metal so is the graphite.

Final Answer: Thus, graphite is a non - metal which is good conductor of electricity.

Choose the incorrect statement among the following

A: Many useful substances are obtained from petroleum and natural gas. These are termed as 'petrochemicals'

B: Hydrogen gas obtained from natural gas is used in the production of fertilizers

C: Due to the great commercial importance of petroleum, it is also called 'black gold'

D: Natural gas is stored under low pressure as compressed natural gas (CNG)

Solution:

Explanation:

The incorrect statement amongst the following is option D, so the correct answer is option D.

This can be elaborated as follows:

Natural gas, comprising mainly of CH ₄ is compressed to CNG at "high pressure ", and not low pressure.

Meanwhile the other statements are all correct.

Like petroleum is termed black gold because of its value to economy(StatementC) ,

petrochemicals are obtained from petroleum and natural gases(Statement A)

and H ₂ obtained from natural gas is utilised in fertilizers(statement B) .

Final Answer:

Hence, the correct answer is determined to be option D.

Coal can be drawn into wires. If it is true then 1, false then 0

A. 0

B. 1

Solution:

Correct Option is: (A)

Explanation:

• Coal is a fossil fuel.
• It is neither malleable nor ductile like metals.
• So, the coal can not be drawn into wires.