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Civil Services Prelims Examination General Science (Chemistry) - GS Paper I

Civil Services Examination 2017


1. Consider the following pairs:

Commonly used/consumed materials and unwanted or controversial chemicals likely to be found in them

1. Lipstick Lead
2. Soft drinks Brominated vegetable oils
3. Chinese fast food Monosodium glutamate

Which of the pairs given above is/are correctly matched?

  1. 1 only
  2. 2 and 3 only
  3. 1 and 3 only
  4. 1, 2 and 3

Civil Services Examination 2014


1. Brominated flame retardants are used in many household products like mattresses and upholstery. Why is there some concern about their use?

  1. They are highly resistant to degradation in the environment.
  2. They are able to accumulate in humans and animals.

Select the correct answer using the code given below.

  1. 1 only
  2. 2 only
  3. Both 1 and 2
  4. Neither 1 nor 2


2. Which one of the following is the process involved in photosynthesis?

  1. Potential energy is released to form free energy
  2. Free energy is converted into potential energy and stored
  3. Food is oxidized to release carbon dioxide and water
  4. Oxygen is taken and carbon dioxide and water vapour are given out


3. Which of the following is / are the example /examples of chemical change?

  1. Crystallization of sodium chloride
  2. Melting of ice
  3. Souring of milk

Select the correct answer using the code given below.

  1. 1 and 2 only
  2. 3 only
  3. 1, 2 and 3
  4. None

Civil Services Examination 2012


1. What is the role of ultraviolet (UV) radiation in the water purification systems?

  1. It inactivates / kills the harmful micro-organism in water.
  2. It removes all the undesirable odours from the water.
  3. It quickness the sedimentation of solid particles, removes turbidity and improves the clarity of water.

Which of the statements given above is/are correct?

  1. 1 only
  2. 2 and 3 only
  3. 1 and 3 only
  4. 1, 2 and 3


2. Lead, ingested or inhaled, is a health hazard. After the addition of lead to petrol has been banned, what still are the sources of lead poisoning?

  1. Smelting Units
  2. Pens and pencils
  3. Paints
  4. Hair oils and cosmetics

Select the correct answer using the codes given below:

  1. 1, 2 and 3 only
  2. 1 and 3 only
  3. 2 and 4 only
  4. 1, 2, 3 and 4


3. Which one of the following sets of elements was primarily responsible for the origin of life on the Earth?

  1. Hydrogen, Oxygen, Sodium
  2. Carbon, Hydrogen, Nitrogen
  3. Oxygen, Calcium, Phosphorus
  4. Carbon, Hydrogen, Potassium


Civil Services Examination 2011


1. The Function of Heavy Water in a Nuclear Reactor is to:

  1. Slow down the speed of neutrons
  2. Increase the speed of neutrons
  3. Cool down the reactor
  4. Stop the nuclear reaction