Class-8 - Chemistry - Chapter-4 - Combustion and Flame

Which one of the following gases is used in combustion?

• Hydrogen

• Oxygen

• Nitrogen

• Carbon dioxide

Which is non-combustible substance?

• Wood

• Paper

• Iron nails

• Straw

Which zone of a flame does a goldsmith use for melting gold and silver ?

• Outer zone

• Middle zone

• Inner zone

• Lower zone

Substances which catch fire are called

• acids

• bases

• combustible

• burners

Which of the following is not a fossil fuel?

• Coal

• Petroleum

• Natural gas

• Water gas

A temperature at which the substance starts burns is called

• melting

• boiling temperature

• ignition temperature

• evaporation

If 150g of fuel is burned the energy produced is 45,000J then find the calorific value of the fuel .

• 3,00,000Kj

• 2,30,000Kj

• 30,000Kj

• 4,50,000Kj