Olympiad – Class VIII – Science - Che - Combustion and Pressure

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Question - 1

What are the two main hydrocarbons present in L.P.G.?

  • A Butane + propane
  • B Butane + isobutane
  • C Propane + ethane
  • D Methane + ethane

Question - 2

What is the heat produced by burning 1 g of fuel completely known as?

  • A Heat capacity
  • B Calorific value
  • C Vapour density
  • D Boiling point

Question - 3

Which of the following has the highest calorific value?

  • A Petrol
  • B Coke
  • C Natural gas
  • D Kerosene

Question - 4

Which of the following has the characteristics of a good fuel?

  • A Coke
  • B Butane
  • C Coal
  • D Kerosene

Question - 5

What is burning of a substance in the presence of air with the evolution of heat called

  • A Distillation
  • B Carbonisation
  • C Combustion
  • D Refining

Question - 6

When methane burns in air, what are the products formed?

  • A CO2 + 2H2O + heat
  • B CO2 + H2
  • C CO + 02
  • D CO2+ 02 + heat

Question - 7

What kind of reaction is combustion?

  • A Reduction
  • B Redox
  • C Substitution
  • D Oxidation

Question - 8

Which of the following is a combustible substance?

  • A Coke 
  • B Coal
  • C Diamond
  • D Wood

Question - 9

What is the lowest temperature at which a substance starts burning called?

  • A Minimum temperature
  • B Maximum temperature
  • C Boiling temperature
  • D Ignition temperature

Question - 10

If the temperature falls below its ignition temperature, then what happens to the burning substance

  • A It gets extinguished.
  • B It burns brightly.
  • C It burns dimly.
  • D It burns with smoke