Organic Basics — Set 5
Chemistry · कार्बनिक रसायन · Questions 41–50 of 50
The primary component of coal gas is?
Correct Answer: A. Hydrogen
Coal gas is a mixture mainly consisting of hydrogen, methane, and carbon monoxide. It was historically used for street lighting before the widespread use of electricity. It is produced during the destructive distillation of coal.
Which substance is used as a preservative for biological specimens?
Correct Answer: A. Formalin
Formalin is a 40% aqueous solution of formaldehyde. It hardens tissues and prevents biological decay by cross-linking proteins. It is widely used in school laboratories and museums.
Which hydrocarbon is the main constituent of 'Gobars gas' (Biogas)?
Correct Answer: A. Methane
Biogas typically contains 50% to 75% methane, along with carbon dioxide. It is produced by the anaerobic digestion of animal waste and plant matter. It serves as an eco-friendly fuel for cooking and lighting in rural areas.
Which organic compound is used in the preparation of dynamite?
Correct Answer: B. Glycerol
Glycerol reacts with nitric acid to form nitroglycerin, the explosive component of dynamite. Alfred Nobel stabilized nitroglycerin using an absorbent material to create dynamite. Glycerol is also a common ingredient in soaps and cosmetics.
Which functional group is present in the compound known as Carbolic acid?
Correct Answer: B. -OH
Carbolic acid is the common name for Phenol, which has an -OH group attached to a benzene ring. It was the first antiseptic used in surgery by Joseph Lister. Phenol is slightly acidic in nature and has a characteristic medicinal smell.
What is the monomer of the synthetic polymer PVC?
Correct Answer: A. Vinyl chloride
PVC stands for polyvinyl chloride, which is made by the polymerization of vinyl chloride. It is widely used for making pipes, raincoats, and flooring materials. It is the third-most widely produced synthetic plastic polymer.
Which organic gas was used as a chemical weapon in World War I?
Correct Answer: C. Mustard gas
Mustard gas is an organic sulfur compound that causes severe blistering of the skin and lungs. It is actually a volatile liquid that forms a mist when deployed. Its chemical name is bis(2-chloroethyl) sulfide.
The primary organic acid present in apples is?
Correct Answer: B. Malic acid
Malic acid is a dicarboxylic acid that contributes to the tart taste of apples. Its name is derived from the Latin word 'malum', meaning apple. It is also found in many other fruits like apricots and cherries.
Which chemical is used to give a distinct odor to odorless natural gas?
Correct Answer: C. Ethyl mercaptan
Ethyl mercaptan (ethanethiol) has a very strong and unpleasant smell like rotten cabbage. It is added to gas supplies in tiny amounts to help detect leaks. This safety measure is crucial because natural gas itself has no smell.
Which of the following describes the functional group of a carboxylic acid?
Correct Answer: B. -COOH
The carboxyl group (-COOH) consists of a carbonyl group and a hydroxyl group. It is the defining feature of organic acids like formic and acetic acid. These acids are generally weak compared to mineral acids like HCl.