Chemistry MCQs
Topic Notes: Chemistry
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
1
Phenol is a key chemical precursor in the industrial manufacturing of which of the following polymers?
Answer:
Bakelite
Bakelite is a thermosetting plastic produced by the condensation polymerization of phenol and formaldehyde. This reaction creates a cross-linked network structure, making the resulting material hard, heat-resistant, and an excellent electrical insulator, which was historically significant as the first synthetic plastic.
2
Which chemical compound serves as the primary starting material for the synthesis of saccharin?
Answer:
toluene
Saccharin, the first artificial sweetener, was originally synthesized from toluene. The industrial process involves the oxidation of o-toluenesulfonamide or the reaction of toluene derivatives with chlorosulfonic acid to form the cyclic imide structure characteristic of saccharin.
3
What is the result of formaldehyde condensing with phenol in the presence of dilute H2SO4?
Answer:
Bakelite
Bakelite is a type of synthetic polymer, also known as phenol-formaldehyde resin, produced through the condensation reaction of phenol and formaldehyde in the presence of acid catalysts.
4
Which molecule undergoes aldol condensation?
Answer:
CH3COCH3
Aldol condensation is a chemical reaction where an aldehyde reacts with itself to form a β-hydroxyaldehyde. CH3COCH3, also known as acetone, is an aldehyde that exhibits this type of condensation.
5
When carboxylic acid reacts with ammonia, and the resulting ammonium salt is heated, what product is formed?
Answer:
Acidamide
Upon heating, the ammonium salt of carboxylic acid undergoes a condensation reaction, resulting in the formation of an acid amide. This reaction is a common method for synthesizing acid amides from carboxylic acids and ammonia.
6
Which of these compounds cannot undergo an aldol condensation reaction?
Answer:
formaldehyde
Aldol condensation requires a compound with at least two carbonyl groups. Formaldehyde only possesses one carbonyl group, preventing the formation of the necessary enolate ion for the reaction.
7
Formaldehyde on condensation in the presence of calcium hydroxide: ______________?
Answer:
Formose
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8
Formaldehyde and lactose are combined to produce throat lozenges named as__________________?
Answer:
formamint
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9
NaOH is named as caustic soda because________________?
Answer:
It corrodes the organic tissues
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10
Which aldehyde does not undergo aldol condensation?
Answer:
Benzaldehyde
Aldol condensation is a reaction between two aldehydes or ketones. Benzaldehyde, being an aromatic aldehyde, does not undergo aldol condensation due to the stability of its benzene ring. The other options are aliphatic aldehydes or ketones that can undergo aldol condensation.