Which of the following chemical formulas represents the main ingredient in natural gas?

• A. H_2O
• B. C_2H_6
• C. CO_2
• D. CH_4

Answer: (D)

Verified step by step guidance

1. Understand that natural gas primarily consists of a simple hydrocarbon, which is a compound made of hydrogen and carbon atoms.
2. Recall the common hydrocarbons: methane (CH_4), ethane (C_2H_6), propane (C_3H_8), and butane (C_4H_{10}).
3. Identify that methane (CH_4) is the simplest hydrocarbon and the main component of natural gas.
4. Compare the given options: H_2O (water), C_2H_6 (ethane), CO_2 (carbon dioxide), and CH_4 (methane).
5. Conclude that CH_4 represents methane, which is the main ingredient in natural gas.