This set of Organic Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Polyhalogen Derivatives”.
1. What will be the product for the given reaction?
Explanation: Benzyl hexachloride will be formed when Benzene reacts with chlorine in presence of U.V light.
C6H6 + 3Cl2 + U.V light → C6H6Cl6
2. The molecular formula of DDT has how many chlorine atoms?
a) 5 chlorine atoms
b) 2 chlorine atoms
c) 3 chlorine atoms
d) 4 chlorine atoms
3. What is the IUPAC name of chloroform?
d) Carbon tetrachloride
Explanation: Chloroform, or trichloromethane, is an organic compound with formula CHCl3. It is a colorless, sweet-smelling, dense liquid that is produced on a large scale as a precursor to PTFE.
4. Which among the following is true?
a) Freon does not initiate radical chain reactions in stratosphere
b) Iodoform initiates radical chain reactions in stratosphere
c) Freon initiates radical chain reactions in stratosphere
d) Chloroform initiates radical chain reactions in stratosphere
Explanation: Freon (Eg: CFCl3– Freon11) does initiate radical chain reactions in stratosphere, which can upset the ozone layer.
5. CFxCly [where x + y = 4], why these compounds are not used?
a) These are fluoro carbons
b) These are difficult to synthesise
c) They deplete ozone layer
d) These are very expensive
Explanation: CFC molecules are made up of chlorine, fluorine and carbon atoms and are extremely stable. This extreme stability allows CFC’s to slowly make their way into the stratosphere (most molecules decompose before they can cross into the stratosphere from the troposphere).
6. Which one of the following is the correct formula of methylene dichloride?
a) ClCH = CHCl
b) ClC ≡ CCl
d) CH2(Cl) CH2Cl
Explanation: As we can see below molecular diagram of methylene dichloride the correct molecular formula is CH2Cl2.
7. Central nervous system can be depressed by the use of which of the following?
Explanation: Acute chloroform intoxication can cause depression of the central nervous system and may lead to death from lethal arrhythmias or respiratory arrest. Thus, the organic solvent is no longer in clinical use as an anaesthetic, but still plays a role in cases of suicide, homicide or inhalation for psychotropic effects.
8. How Benzene hexachloride (BHC) is used?
Explanation: Benzene hexachloride. Benzene hexachloride (BHC), any of several stereoisomers of 1,2,3,4,5,6-hexachlorocyclohexane formed by the light-induced addition of chlorine to benzene. One of these isomers is an insecticide called lindane, or Gammexane.
9. Depletion of Ozone is believed to increase which of the following?
b) Ultraviolet rays
Explanation: Ozone layer depletion increases the amount of UVB that reaches the Earth’s surface. Laboratory and epidemiological studies demonstrate that UVB causes non-melanoma skin cancer and plays a major role in malignant melanoma development.
10. Which is the correct formula of Freon-12?
Explanation: As we can see below molecular diagram of Freon-12, the correct molecular formula is CCl2F2.
Sanfoundry Global Education & Learning Series – Organic Chemistry.
To practice all areas of Organic Chemistry, here is complete set of 1000+ Multiple Choice Questions and Answers.