Question

Which of the following hydrocarbons exists mostly in solid or liquid form under the earth surface?
A. Ethane
B. Methane
C. Pentane
D. Butane

Answer 1

Hint : Hydrocarbons are known as organic compounds that are entirely made up of only two kinds of atoms that are carbon and hydrogen. Hydrocarbons are colourless gases that have very weak odours. Hydrocarbons have simple or relatively complex structures and can be generally classified into four subcategories, namely alkanes, alkenes, alkynes.

Complete Step By Step Answer:
Crude oil and natural gas contain mixtures of hydrocarbons that contain only hydrogen and carbon.
The heavier a molecule, more likely it exists as a liquid or solid at normal and under surface condition.
Under surface pressure and temperature conditions, lighter hydrocarbons like methane, ethane propane and butane occur as gases. As pentane is a heavier hydrocarbon, it can exist in the form of liquids or solids.
Alkanes have low boiling points and melting points because of their weak Van Der Waal interaction.
Hence, the correct option is C. Pentane.

Additional Information:
Hydrocarbons such as propane and butane are known to be used for commercial fuel purposes in the form of Liquefied Petroleum Gas (LPG). Benzene is known as one of the simplest aromatic hydrocarbons that serves as raw material for the synthesis of many synthetic drugs.

Note :
Hydrocarbons can be gases like methane and propane. Hydrocarbons can be liquids like hexane, benzene. Hydrocarbons can be solids like paraffin wax and naphthalene. Hydrocarbons can further be classified as aliphatic and alicyclic hydrocarbons. Boiling points of hydrocarbons depends on molecular mass and branching.