Question

The strong-smelling substance added to LPG is:
A. ethyl mercaptan
B. ethanol
C. ethanal
D. ethyl butane

Answer 1

Hint: The full form of LPG is liquified petroleum gas. When it is filled in any steel container, cylinder or tank, the gas is stored at a pressure higher than atmospheric pressure. Gases at high pressure tend to liquify. As the filler cylinder feels heavy, we conclude that gases are lighter than liquids.

Complete step by step answer:
Liquefied petroleum gas, like all other fossil fuels, is a non-renewable source of energy i.e., cannot be renewed once lost. It is generally extracted from crude oil and natural gas.
The main composition of LPG are hydrocarbons containing three or four carbon atoms at the most. The normal components of LPG are propane and butane. Thus, LPG is a gas at atmospheric pressure and normal ambient temperatures, but it can be liquefied on applying moderate pressure or when the temperature is sufficiently reduced.
It can be easily condensed, packaged, stored, and used, which makes it a source of an ideal energy for a wide range of applications. Normally, the gas is stored in liquid form under high pressure in steel containers, cylinders or tanks at the production and manufacturing site, hence the gas remains in liquid state.
This liquid state gas is then transferred to the gas cylinders at the LPG filling plants which we see in our house. These cylinders which are supplied to our home have a regulator, which regulates the pressure in it. When the valve or regulator is opened, the pressure inside the gas cylinder decreases and the liquid changes into gaseous form, which we use to cook food.
The butane is odorless; therefore, a smelling agent is added which is ethyl mercaptan. The formula is \[{C_2}{H_6}S\] .

So, the correct answer is A.

Note:LPG is highly inflammable and therefore it must be stored away from sources of ignition and in a well-ventilated area. LPG vapor is heavier than air, so any leakage will sink and accumulate nearby areas as LPG expands rapidly when its temperature rises. A container is filled with sufficient space to allow for such expansion.