The lowest temperature at which a substance catches fire is called its:
ignition temperature
The correct answer is Option 4: ignition temperature.
What is Ignition Temperature?
The ignition temperature (also known as the kindling temperature) is the lowest temperature at which a combustible substance catches fire and begins to burn sustainably in the presence of air or oxygen, without an external spark or flame.
Inflammable Substances: Materials that have a very low ignition temperature can catch fire easily (even with a tiny spark). Examples include petrol, alcohol, and Liquefied Petroleum Gas (LPG).
Fire Control: Knowing the ignition temperature is crucial for fire safety. For a fire to occur, three things are needed (the Fire Triangle): fuel, oxygen, and enough heat to raise the fuel to its ignition temperature. Removing the heat (by cooling it with water) lowers the temperature below the ignition point and puts out the fire.
Quick Look at the Other Options:
Melting point: The temperature at which a solid substance turns into a liquid (e.g., ice melting into water at 0°C).
Boiling point: The temperature at which a liquid turns into a gas/vapor throughout the liquid (e.g., water boiling at 100°C).
Normal temperature: Usually refers to standard room temperature or average body temperature, which is not related to combustion.
Important Questions from States of Matter
A liquid is heated up to a certain temperature. Which one of the following situation would correspond to the boiling of the liquid?
Which one among the following oxides has the highest melting point?
Equal volume of all gases, when measured at the same temperature and pressure, contain an equal number of particles. Who proposed the above law?
Match List I with List II and select the correct answer using the code given below the Lists:
Code:List I (Noble gas)
List II (Use)
A. Argon
1. In lights for advertising display
B. Neon
2. Airport landing lights and in light houses
C. Krypton
3. Light in photographer’s flash gun
D. Xenon
4. In tungsten filament to last
Match List-I with List-II and select the correct answer using the code given below the Lists:
List I
(Process)
List II
(Type of change)
A. Heating of camphor
1. Chemical
B. Cooling of water vapor up to room temperature
2. Evaporation
C. Cooking an egg
3. Condensation
D. Formation of water vapor at room temperature.
4. Sublimation
