Question

Which of the following statements are true about Combustion.

• A. it is a kind of chemical change
• B. it requires carbon dioxide
• C. it is a slow process
• D. it releases heat as well as light energy.

Answer 1

Answer: (A), (D)

it releases heat as well as light energy.

Explanation for the correct options:

Combustion: Combustion is an exothermic chemical reaction, in which a substance (fuel) burns with the help of oxygen to produce carbon dioxide, water vapor, heat, and light.

Example: Burning of hydrocarbon (methane) completely in the presence of oxygen gives out carbon dioxide, water vapor, and energy in the form of heat, and light.

$\underset{\mathrm{Methane}}{{\mathrm{CH}}_4}+\underset{\mathrm{Oxygen}}{2{\mathrm{O}}_2}\to \underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2}+\underset{\mathrm{Water}}{2{\mathrm{H}}_2\mathrm{O}}+\mathrm{Heat}$

Option A

• A chemical change is a change in which new substances are formed.
• Thus combustion is a chemical reaction in which new substances are formed in the form of carbon dioxide, and water.
• It also releases heat and light.

Option D

Combustion is a process of burning of substance in the presence of oxygen to release heat and light.

Thus options A and D are correct options.