Chemistry

Acids and Bases

594 Questions

Acids and bases questions cover the chemical properties, common examples, and theoretical concepts of acidic and basic substances. Topics include identifying proton acceptors, recognizing amphoteric substances, and knowing the sources of everyday organic acids. These foundational chemistry questions are common across SSC, banking, and railways examinations.

Acid and base propertiesOrganic acidsAmphoteric substancesProton donors and acceptorsChemical formulas

Acids and Bases Questions

Multiple choice

Carbolic acid is called _____

  1. Phenol

  2. Phenyl

  3. Benzene

  4. Benzoic acid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Carbolic acid is the common name for phenol (C6H5OH). Phenyl is the C6H5- group, benzene is C6H6, and benzoic acid is C6H5COOH. The -OH group attached directly to the benzene ring gives phenol its acidic properties.

Multiple choice

Acetic acid is ______

  1. Strong acid

  2. Weak acid

  3. Neutral acid

  4. Amphotreric acid

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Acetic acid (CH3COOH) is a weak acid because it only partially ionizes in water. Strong acids like HCl or H2SO4 completely dissociate, but acetic acid exists in equilibrium with its conjugate base. The Ka value of acetic acid is approximately 1.8 x 10^-5, confirming its weak acid nature.

Multiple choice

Which acid is present in vinegar?

  1. Formic

  2. Acetic

  3. Oxalic

  4. Ascorbic

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Vinegar contains approximately 5-8% acetic acid by volume. Acetic acid gives vinegar its characteristic sour taste and pungent odor. Formic acid is found in ant venom, oxalic acid in spinach and rhubarb, and ascorbic acid is vitamin C.

Multiple choice

Due to presence of _______ lemon is sour?

  1. Citric acid

  2. Nucleic acid

  3. Acetic acid

  4. Ascorbic acid

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Lemons are sour due to the presence of citric acid, which makes up about 5-6% of their dry weight. Citric acid is a weak organic acid that gives citrus fruits their characteristic tart flavor. Nucleic acids are DNA/RNA, acetic acid is in vinegar, and ascorbic acid is vitamin C.

Multiple choice

Acetic acid is ________.

  1. Not ionized

  2. Slightly ionized

  3. Completely ionized

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Acetic acid is slightly ionized in aqueous solution because it is a weak acid. Only about 1% of acetic acid molecules dissociate into H+ and CH3COO- ions in water. Strong acids are completely ionized, while non-ionized substances do not dissociate at all.

Multiple choice

Pyruvic acid is reduced in the presence of Na-Hg/H2O to form

  1. lactic acid

  2. crotonic acid

  3. tartronic acid

  4. citric acid

  5. aconitic acid
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This option is correct because pyruvic acid is treated with Na-Hg/H2O to form lactic acid. It is found in curd, which is beneficial for human beings.

Multiple choice

Acetic acid is present in

  1. vinegar

  2. curd

  3. lime

  4. none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Vinegar contains approximately 5-8% acetic acid by volume, which gives it its characteristic sour taste and pungent smell. Acetic acid is produced through the fermentation of ethanol by acetic acid bacteria, converting alcohol into this weak organic acid.

Multiple choice

KOH can be classified as

  1. strong acid

  2. weak acid

  3. strong base

  4. weak base

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

KOH can be classified as strong base.