Chemistry Aptitude Test for IIT JEE Exam on “Haloalkanes & Haloarenes – Polyhalogen Compounds”.
1. Which of the following is not a use of methylene chloride?
a) Paint removal
b) Propellant in aerosols
c) Metal cleaning
d) Antiseptic
Answer: d
Clarification: Methylene chloride can harm the human central nervous system and application on the skin may result in intense burning and redness.
2. Which of the following is an effect of exposure to low levels of dichloromethane in the air?
a) Slightly impaired vision
b) Dizziness
c) Nausea
d) Numbness in fingers
Answer: a
Clarification: Dizziness, nausea and numbness are caused due to higher levels of dichloromethane in the air. Lower levels cause slight impairment of hearing and vision.
3. The oxidation of trichloromethane results in the formation of a poisonous gas called ________
a) carbon monoxide
b) carbonyl chloride
c) hydrogen sulphide
d) phosphine
Answer: b
Clarification: Trichloromethane is slowly oxidized in air in the presence of light to form an extremely poisonous gas, carbonyl chloride, also called as phosgene.
4. Chloroform was previously used as a general anaesthetic in surgery.
a) True
b) False
Answer: a
Clarification: It was stop being used as an anaesthetic due to its toxicity and harmful effects on the human body. It was replaced by safer options like ether.
5. What is the reason for iodoform to be used as an antiseptic?
a) Due to its unpleasant odour
b) Due to its melting point
c) Due to its solubility in alcohol
d) Due to the liberation of free iodine
Answer: d
Clarification: The antiseptic properties of iodoform are due to the liberation of free iodine and not due the properties and characteristics of iodoform itself.
6. Which of the following polyhalogen compounds in useful in extinguishing fires?
a) Dichloromethane
b) Trichloromethane
c) Triiodomethane
d) Tetrachloromethane
Answer: d
Clarification: Carbon tetrachloride is used as a cleaning fluid, degreasing agent, spot remover and a fire extinguisher.
7. Carbon tetrarchloride may indirectly cause skin cancer.
a) True
b) False
Answer: a
Clarification: When CCl4 is released into the atmosphere, it causes the depletion of the ozone layer, which increases exposure to UV rays leading to skin cancer, eye diseases and disorders.
8. Which of the following is not a freon?
a) CCl3F
b) CCl2F2
c) CBr2F2
d) CClF3
Answer: c
Clarification: Freons are chlorofluorocarbon compounds of methane and ethane. The compound CBr2F2 contains bromine, and hence is not a freon.
9. Freon 12 is manufactured from the Swarts reaction of which compound?
a) Dichloromethane
b) Trichloromethane
c) Tetrachloromethane
d) Dichlorodifluoromethane
Answer: c
Clarification: Freon 12 (CCl2F2) is obtained by heating CCl4 with antimony fluoride in the presence of antimony pentachloride by Swarts reaction.
10. Which of the following is not a characteristic of CHClF2?
a) Non-toxic
b) Non-flammable
c) Non-corrosive
d) Non-liquefiable
Answer: d
Clarification: CHClF2 is a freon refrigerant also known as R-22. It is extremely stable, unreactive, non-toxic, non-corrosive and an easily liquefiable gas.
11. Which of the following is not a harmful effect of DDT?
a) It is non-biodegradable
b) Cannot be metabolized by animals
c) Highly toxic towards fish
d) Causes air pollution
Answer: d
Clarification: The chemical stability and fat solubility of DDT is a big drawback. It was banned due to its harmful effect on animals and fish.
12. Which of the following is not a use of carbon tetrachloride?
a) Manufacturing of refrigerants
b) Manufacturing of pharmaceuticals
c) Degreasing agent
d) Insecticide
Answer: d
Clarification: CCl4 is produced in large quantities for use in the making of refrigerants and propellants for aerosol cans. It is also used as feedstock in pharmaceutical manufacturing and synthesis of chlorofluorocarbons.
Chemistry Aptitude Test for IIT JEE Exam,