CBSE Questions for Class 8 Chemistry Combustion And Flame Quiz 5 - MCQExams.com

The blue zone in a LPG flame indicates _________.
  • unburnt vapours
  • partial decomposition
  • moderately hot
  • hottest and complete combustion
Which is the hottest part of Bunsen flame?
  • In the blue zone
  • Just above the tip of the primary flame
  • At the top of the outer core
  • Just above the inner core
Choose the correct statement among the following.
  • The substances which vapourise during burning, do not give flames.
  • The substances which have very high ignition temperature are called inflammable substances.
  • When the matchstick is struck against the rubbing surface, some red phosphorous gets converted into white phosphorous.
  • The job of a fire extinguisher is to cut off the supply of carbon dioxide, and hence the fire is controlled.
Match Column I with Column II and select the correct option from the codes given below.
Column IColumn II
(a)Hottest zone of a candle flame(i)Zone of unburnt wax vapours
(b)Yellow zone of a candle flame(ii)Non-luminous zone
(c)Black innermost zone of the candle flame(iii)Incomplete combustion zone
  • (a) - (i), (b) - (ii), (c) - (iii)
  • (a) - (ii), (b) - (i), (c) - (iii)
  • (a) - (i), (b) - (iii), (c) - (ii)
  • (a) - (ii), (b) - (iii), (c) - (i)
The combustion in which a material bursts into flames without the application of heat is known as :
  • complete combustion
  • spontaneous combustion
  • slow combustion
  • none of these
Coal, petroleum, natural gas and propane are fossil fuels. They are called fossil fuels because ________.
  • they are burnt to release energy and they cause air pollution.
  • they were formed from the buried remains of plants and tiny animals that lived hundreds of millions of years ago.
  • they are non renewable and will run out.
  • they are mixed with fossils to provide energy.
One of the phenomenon which cannot be described as combustion is:
  • oxidation of coal in air
  • burning of magnesium in nitrogen
  • reaction of antimony in chlorine
  • lighting of an electric lamp
In photosynthesis in plants, $${H}_{2}O$$ and $${CO}_{2}$$ react in presence of light and chlorophyll to give carbohydrate and oxygen. When the carbohydrate is burnt in air, the gases produced are:
  • $${CO}_{2}+{H}_{2}$$
  • $${CO}_{2}+CO$$
  • $${CO}_{2}+{H}_{2}O$$
  • $${CO}_{2}+{O}_{2}$$
Which of the following diagrams shows a non-luminous flame?
315295_5aa0622b02c641b9a7bf848330670737.png
  • I only
  • II only
  • I and II
  • II and IV
When a burning candle is covered with a glass it extinguishes because:
  • supply of oxygen is cut off
  • supply of hydrogen is cut off
  • supply of nitrogen is cut off
  • supply of $$CO_2$$ is cut off
There are holes below the chimney of an oil lamp:
  • to supply oxygen for burning the oil
  • to let the smoke escape
  • to increase the brightness of the lamp
  • None of these
The characteristic(s) of a ideal fuel is(are):
  • it should release a large amount of energy
  • it should burn moderately in air
  • it should be easily transported
  • all of the above
Which among the following has the highest calorific value?
  • Petrol
  • Cow dung cake
  • Coal
  • Wood
The flame of the candle has three zones. The outer zone is blue, the middle zone is yellow and the inner zone is black. Which is correct regarding this?
  • The outer zone is least hot
  • The middle zone is hottest
  • The inner zone is least hot
  • All the zones have same temperature

Which of the following is combustible?
  • Oxygen
  • Carbon dioxide
  • Hydrogen
  • All of the above
Which of the following is a supporter of combustion?
  • Cooking gas
  • Nitrogen gas
  • Oxygen gas
  • Producer gas
Which of the following flames is produced by a candle?
  • Green flame
  • Non-luminous flame(blue)
  • Light giving flame
  • Yellow luminous flame
Quality that is not suitable for a fuel is ________ .
  • high calorific value with ignition temperature that is well above the normal room temperature
  • low rate of evaporation at room temperature
  • carbon particles are expelled with smoke
  • low content of non-combustibles
The lowest temperature at which a combustible substance catches fire is called:
  • critical temperature
  • absolute temperature
  • ignition temperature
  • none of these
State true or false.
Fossils are present in metamorphic rocks. 
  • True
  • False
______ is the extinguisher used for inflammable material like petrol.
  • Water
  • $$CO_2$$
  • Oil
  • Dry powder
Nitrogen is a component of air that does not support combustion.
  • True
  • False
Oxygen is the component of air that supports combustion.
  • True
  • False
Ideal fuel has a __________ calorific value.
  • low
  • high
  • moderate
  • zero
Carbon dioxide is used in fire extinguisher.
  • True
  • False

Carbon dioxide is neither combustible nor a supporter of combustion.
  • True
  • False
Which of the following has lower ignition temperature?
  • Wood
  • Paper
  • Vegetable oil
  • Kerosene oil
Oxygen supports combustion and is used up in burning.
  • True
  • False
Charcoal burns in air to produce ______.
  • $$CO_2$$
  • $$H_2O$$
  • $$H_2$$
  • $$O_2$$
A candle burns in a jar of oxygen but is extinguished in nitrogen.
  • True
  • False
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 8 Chemistry Quiz Questions and Answers