In the chemical equation C_7H_{16} (l) + 11O_2 (g) → 7CO_2 (g) + 8H_2O (l), what do the symbols in parentheses (l) and (g) indicate?

• A. They indicate the physical states of the substances: (l) for liquid and (g) for gas.
• B. They indicate the type of chemical bond present in each compound.
• C. They indicate the temperature at which the reaction occurs.
• D. They indicate the concentration of the substances in solution.

Answer: (A)

Verified step by step guidance

1. Identify the symbols in parentheses next to each chemical formula in the equation: (l) and (g).
2. Recall that in chemical equations, symbols in parentheses indicate the physical state of each substance involved in the reaction.
3. Understand that (l) stands for liquid, meaning the substance is in the liquid phase under the reaction conditions.
4. Recognize that (g) stands for gas, meaning the substance is in the gaseous phase under the reaction conditions.
5. Conclude that these symbols do not indicate bond types, temperature, or concentration, but specifically the physical states of the substances.