Chemistry

Acids and Bases

579 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

Which of the following sets represents soft acids only?

  1. Ni(0), Cu(I), Mg(II), Al(III)

  2. Ni(0), Cu(I), Hg(II), Pt(II)

  3. Cu(I), Cu(II), Hg(II), Fe(III)

  4. Ag(I), Au(I), Zn(II), Mg(II)

  5. Li(I), Ca(II), Al(III), Si(IV)
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ni(0), Cu(I), Hg(II), Pt(II) : All are soft acids

Multiple choice

Which of the following acids is/are used for preparing TNT and dynamite?

  1. Sulphuric acid
  2. Hydrochloric acid
  3. Nitric acid

  1. Only 1

  2. Only 3

  3. Only 1 and 2

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

In an industry, TNT is produced in a three-step process. First, toluene is nitrated with a mixture of sulphuric and nitric acid to produce mononitrotoluene (MNT). The MNT is separated and then renitrated to dinitrotoluene (DNT). In the final step, the DNT is nitrated to trinitrotoluene (TNT) using an anhydrous mixture of nitric acid and oleum. Nitric acid is consumed by the manufacturing process, but the diluted sulphuric acid can be reconcentrated and reused. 

Multiple choice

According to Arrhenius concept of acids and bases, “An acid is a substance which is capable of furnishing H+ ions in aqueous solution and base is a substance which is capable of furnishing OH– ions”. Which of the following statements does not represent the limitations of Arrhenius theory?

  1. It fails to explain the behaviour of acids and bases in a non-aqueous solution.

  2. It fails to explain the neutralisation reaction giving salt in the absence of solvent.

  3. It only explains the existence of hydrogen ion in water.

  4. It fails to explain the acidic character of certain salts like AlCl3, BF3, etc. and basic character of NH3, PH3, etc.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

It does not explain the existence of hydrogen ion in water.

Multiple choice

Directions: Use the following information to answer the question.

According to Arrhenius concept, a stronger acid produces greater number of H+ ions in the aqueous solution and vice-versa.

Out of 0.1 M HNO3, 0.1 M CH3COOH, 0.1 M HCl and 0.1 M H2SO4, which is the strongest acid?

  1. 0.1 M HCl

  2. 0.1 M H2SO4

  3. 0.1 M HNO3

  4. 0.1 M CH3COOH
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Concentration of hydrogen ion [H+] in 0.1 M HNO3 = 0.1 M 0.1 M CH3COOH = Less than 0.1 M because it is a weaker acid. 0.1 M HCL = 0.1 M 0.1 M H2SO4 = 0.2 M [because it ionises as H2SO4 ⇌ 2H+ + SO42-] [H+] = 2 × [H2SO4] = 2 × 0.1 = 0.2 M Hence, 0.1 M H2SO4 is the strongest acid.

Multiple choice

Directions: Use the following information to answer the question.

According to Arrhenius concept, a stronger acid produces greater number of H+ ions in the aqueous solution and vice-versa.

A chemist has 0.01 M solution of each of NH4OH, Ca(OH)2, Al(OH)3 and NH2OH. Out of these, which is the strongest base?

  1. 0.01 M NH4OH

  2. 0.01 M Al(OH)3

  3. 0.01 M Ca(OH)2

  4. 0.01 M NH2OH
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

All these are weak bases and [OH–] in each of these compounds is given as follows: 0.01 M NH4OH = 0.01 M 0.01 M Al(OH)3 = 0.03 M 0.01 M Ca(OH)2 = 0.02 M 0.01 M NH2OH = 0.01 M

Multiple choice

Which acid is present in lemon?

  1. Lactic acid

  2. Citric acid

  3. Tartaric acid

  4. Acetic acid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Citrus fruits including lemons contain citric acid as their primary acid. Citric acid gives lemons their characteristic sour taste and can constitute up to 8% of the lemon's dry weight. Lactic acid is found in fermented milk products, tartaric acid in grapes, and acetic acid in vinegar.

Multiple choice

Which acid is present in lemon?

  1. Lactic acid

  2. Citric acid

  3. Tartaric acid

  4. Acetic acid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Citric acid is naturally found in citrus fruits like lemons, oranges, and limes. It gives these fruits their characteristic sour taste and is widely used as a food preservative and flavoring agent. Lactic acid is found in milk, tartaric acid in grapes, and acetic acid in vinegar.