Explanation

• LPG stand for Liquefied Petroleum Gas
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• In order to supply fuel efficiently to the populace, we have four LPG Storage and Bottling Plants, one each in Karachi, Lahore, Dhurnal, and Akora Khattak.
• LPG is used as a fuel gas in heating appliances, cooking equipment, and vehicles
• LPG is prepared by refining petroleum or "wet" natural gas,
•  LPG was first produced in 1910 by Walter O. Snelling.

Explanation

Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that is produced when coal is burned without sufficient oxygen.

CO is highly toxic.

It can be deadly in high concentrations, as it displaces oxygen in the bloodstream.

Explanation

The percentage of oxygen in the air is about 20.95%.

The air is made up of many gases, including oxygen, nitrogen, argon, and carbon dioxide

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Nitrogen

Nitrogen is the most abundant gas in the air, making up about 78% of it. 

Argon

Argon is the third most abundant gas in the air, making up about 0.93% of it. 

Carbon dioxide

Carbon dioxide is present in trace amounts in the air, making up about 0.04% of it. 

Explanation

The Sun is primarily made up of hot gases, mainly hydrogen (about 74%) and helium (about 24%),

In a plasma state due to extreme temperatures.

Explanation

 Oxy-acetylene welding:

This is the most common type of gas welding, where oxygen and acetylene are mixed to produce a high-temperature flame that melts the metal pieces to be joined. 

Additional information:

ii. (Acetylene + Carbon):

While acetylene is a key component in gas welding, it needs oxygen to create the combustion necessary for the welding process.

Carbon alone doesn't provide the necessary oxidation. 

iii. (Oxygen + Hydrogen):

Although oxygen is used in welding, hydrogen is not typically used in this context.

Hydrogen and oxygen can form water vapor, which could hinder the welding process. 

Explanation

Graham's Law of Diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of its molar mass.

$$\text{<font color="\#0000ff"><b>Rate</b></font>}<font\; color="\#0000ff"><b>\propto </b></font>\frac{\mathrm{<font\; color="\#0000ff"><b>1</b></font>}}{\sqrt{\mathrm{<font\; color="\#0000ff"><b>M</b></font>}}}$$

Compare molar masses:

CH₄ (Methane): 16 g/mol

N₂ (Nitrogen): 28 g/mol

O₂ (Oxygen): 32 g/mol

H₂ (Hydrogen): 2 g/mol (lightest)

Since H₂ has the smallest molar mass, it diffuses the most rapidly.

Explanation

• The primary component of natural gas is methane (CH4).
• Making up 70% to 90% or more of its composition.
• It is a colorless, odorless, and highly flammable hydrocarbon gas.
• Characteristics: It is a fossil fuel, often found in rock formations alongside oil or on its own. 

Last updated question 15 March2026

Explanation

Hydrogen is present in the atmosphere in trace amounts, making it the least common among the listed gases.

Nitrogen (~78%), Oxygen (~21%), and Argon (~0.93%) are much more abundant.

Explanation

Radon (Rn) is a radioactive gas formed from the decay of uranium and radium found in rocks and soil.

He (Helium): Helium is present in trace amounts in the atmosphere.

Ne (Neon): Neon is also present in trace amounts in the atmosphere.

Ar (Argon): Argon is the most abundant noble gas in Earth's atmosphere, making up about 0.93% of the air. 

Explanation

The term fluids refers to both liquids and gases, as they can flow.

Liquids specifically are also classified under fluids because of their ability to take the shape of a container.