Question

Three substances P, Q and R are burnt. P burns quickly producing heat and light. Q burns at room temperature on its own. R burns with heat and light and produces a loud sound. It also liberates a lot of gases while burning. What type of combustion does P, Q and R undergo?

• A. P: Rapid combustion
  Q: Rapid combustion
  R: Explosion
• B. P: Spontaneous combustion
  Q: Spontaneous combustion
  R: Rapid combustion
• C. P: Rapid combustion
  Q: Spontaneous combustion
  R: Explosion
• D. P: Spontaneous combustion
  Q: Rapid combustion
  R: Explosion

Answer 1

The correct option is C P: Rapid combustion

Q: Spontaneous combustion
R: Explosion
<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> $\bullet$ When a substance burns quickly and produces heat and light, then it is said to have undergone rapid combustion. So, P has undergone rapid combustion.

$\bullet$ When a substance burns on its own without the help of any external agent, then it is said to have undergone spontaneous combustion. Hence, Q has undergone spontaneous combustion.

$\bullet$ When a substance burns with the evolution of a lot of heat, light, sound and gases, then it is said to have undergone an explosion. Therefore, R has undergone an explosion.