Question

1. in a combustion reaction, one of the products is always _______

a) hydrogen

b) carbon dioxide

c) oxygen

d) liquid

Explanation:

Identify the definition of a combustion reaction

$$ \text{Hydrocarbon} + \text{O}_2 ightarrow \text{CO}_2 + \text{H}_2\text{O} $$

Analyze the given options

• A) Hydrogen: Usually a reactant or not present as elemental \(H_2\).
• B) Carbon dioxide: Always produced in the complete combustion of a hydrocarbon.
• C) Oxygen: A reactant, not a product.
• D) Liquid: Products can be in gaseous or other states depending on temperature.

Determine the correct choice

$$ \text{Correct Option} = \text{B} $$

Answer:

• (A) hydrogen
• (B) carbon dioxide (Correct answer)
• (C) oxygen
• (D) liquid