COMBUSTION

Why does a matchstick not catch fire on its own at room temperature?

• It does not have enough oxygen

• temperature is below the ignition temperature
  

• It lacks fuel
  

• It is a non-combustible material

Which of the following factors will extinguish a fire?

• Adding more oxygen
  

• Increasing the temperature of the fuel above its ignition temperature
  

• Removing oxygen from the fire's surroundings
  

• Increasing the amount of fuel

What makes kerosene oil more flammable than wood?

• Kerosene has a higher vapor pressure than wood
  

• Kerosene is a gas, while wood is a solid
  

• Kerosene requires less heat to ignite
  

• Wood can only ignite in dry conditions

What is the primary mechanism by which carbon dioxide extinguishes flames?

• It cools the fire by absorbing heat
  

• It displaces oxygen in the air surrounding the fire
  

• It chemically alters the fuel to prevent combustion
  

• It increases the concentration of flammable gases

A piece of paper burns easily, but paper wrapped around an iron rod does not. Why?

• The paper in contact with the iron rod does not reach its ignition temperature
  

• The iron rod absorbs oxygen from the paper
  

• The iron rod prevents the paper from producing flames
  

• The paper becomes non-combustible when near the iron rod

Which part of a flame is typically the coolest?

• The dark zone
  

• The luminous zone
  

• The non-luminous zone
  

• The outermost zone

Why are safety matches safer than earlier versions of matches?

• They use white phosphorus, which ignites easily
  

• They contain powdered glass, which acts as a fuel
  

• They do not require friction to ignite
  

• They only ignite when struck on a specific surface

During the combustion of coal, which of the following gases is primarily released?

• Carbon monoxide
  

• Oxygen

• Sulfur dioxide

• Carbon dioxide

Which of the following will not form a flame during burning?

• Kerosene oil

• Camphor
  

• Charcoal
  

• LPG

What is the primary reason for the higher temperature in the non-luminous zone of a flame compared to the luminous zone?

• It is closer to the source of fuel
  

• It allows for more efficient combustion, generating additional heat

• It is shielded from direct exposure to air

• It contains excess fuel particles