What is a naturally occurring mixture of short chain hydrocarbons with a minor amount of inorganic compounds?

• A. Methane
• B. Ethane
• C. Propane
• D. Natural Gas

Answer: (D)

Natural gas is a naturally occurring mixture of low molecular weight hydrocarbons, predominantly methane, with smaller amounts of other short-chain hydrocarbons such as ethane and propane, plus trace inorganic compounds like carbon dioxide, hydrogen sulfide, and water vapor. This combination fits the description of a mixture rather than a single pure compound. The other options are individual hydrocarbons (pure substances), not mixtures, so they don’t match the definition.