Question

Along with methane, natural gas contains _____ % ethane.
(A) 90-95
(B) 70-80
(C) 50-60
(D) 10-20

Answer 1

Hint: Natural gas or fossil gas is the gas which gets produced naturally by the action of heat and pressure over millions of years. Methane is the main constituent of natural gas.

Complete step by step solution:
Natural gas is a naturally occurring mixture of gases. It is also called fossil gas. It has only the hydrocarbons in its constitution. However, a small amount of carbon dioxide, helium and nitrogen may be present in it.
- It is formed by the decomposition of plant and animal matter by the effect of pressure and heat over millions of years. So, it is a non-renewable source. It can be used for cooking, heating and for production of electricity. Natural gas can be used to produce hydrogen gas as well. It can be also used to produce fabrics, glass, steel, oil and many other products.
- The main constituent gas of the natural gas is methane. The other higher alkanes are present in the gas in smaller amounts. The % of ethane in the natural gas may vary from 10 to 20%. Depending upon the region of extraction, the composition of natural gas may vary slightly.
- Alongside methane and ethane; butane, propane and pentane are also present in natural gas.
- Thus, we can conclude that ethane is present in natural gas and its composition is 10-20%.

So, the correct answer is (D).

Note: Note that in some regions, the obtained natural gas may have a little less or more than 10-20% of ethane. Ethane has a chemical formula of ${C_2}{H_6}$ and it is a higher analogue of methane. It is a colourless, odourless and combustible gas.