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
Which of the following compounds is an acid with a basicity of one?
Answer:
sodium dihydrogen phosphate
Basicity of an acid refers to the number of replaceable hydrogen ions per molecule. Sodium dihydrogen phosphate (NaH2PO4) can release one proton in a neutralization reaction, making it a monobasic acid in that context, whereas phosphoric acid (H3PO4) is tribasic.
2
In the reaction between the hydrogen sulfate ion and water (HSO4- + H2O -> H3O+ + SO4^2-), what is the role of water?
Answer:
a base
According to the Bronsted-Lowry theory, a base is a proton acceptor. In this reaction, water accepts a proton (H+) from the hydrogen sulfate ion to form the hydronium ion (H3O+). Since water accepts a proton, it acts as a Bronsted-Lowry base in this specific chemical transformation.
3
Evaluate the following statements regarding acid ionization: 1. Strong acids like HCl, H2SO4, and HNO3 ionize completely to produce high concentrations of H+ ions. 2. Weak acids like CH3COOH, H2CO3, and H2SO3 ionize partially in water to produce low concentrations of H+ ions.
Answer:
Both 1 and 2 are correct
Strong acids are defined by their ability to dissociate completely in aqueous solutions, resulting in a high concentration of hydronium ions. Conversely, weak acids undergo incomplete dissociation, establishing an equilibrium where only a small fraction of the acid molecules release H+ ions. Both statements accurately describe these fundamental chemical behaviors.
4
Who synthesized the first organic compound in a laboratory setting?
Answer:
Wohler
Friedrich Wöhler is credited with synthesizing urea in 1828, the first organic compound produced in a laboratory. This breakthrough disproved the vital force theory, showing that organic compounds could be created without biological organisms, marking a significant milestone in organic chemistry.
5
Considering Bronsted-Lowery theory, a base is a
Answer:
proton acceptor
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6
Considering Bronsted-Lowery theory, an acid is a
Answer:
proton donor
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