CBSE Class 11 Ionic Equilibrium In solution Worksheet A

Question. Degree of dissociation of 0.1 N CH₃COOH is:
(Dissociation constant = 1 × 10^–5)
a. 10^–5
b. 10^–4
c. 10^–3
d. 10^–2
Answer : D

Question. In weak electrolytic solution, degree of ionization:
a. Will be proportional to dilution
b. Will be proportional to concentration of electrolyte
c. Will be proportional to the square root of dilution
d. Will be reciprocal to the dilution
Answer : C

Question. Vant hoff factor of BaCl₂ of conc. 0.01M is 1.98. Percentage dissociation of BaCl₂ on this conc. Will be:
a. 49
b. 69
c. 89
d. 98
Answer : A

Question. At infinite dilution, the percentage ionisation for both strong and weak electrolytes is:
a. 1%
b. 20%
c. 50%
d. 100%
Answer : D

Question. Electrolytes when dissolved in water dissociate into their constituent ions. The degree of dissociation of an electrolyte increases with:
a. Increasing concentration of the electrolyte
b. Decreasing concentration of the electrolyte
c. Decreasing temperature
d. Presence of a substance yielding a common ion
Answer : B

Question. Which of the following substance is an electrolyte?
a. Chloroform
b. Benzene
c. Toluene
d. Magnesium chloride
Answer : D

Question. The addition of a polar solvent to a solid electrolyte results in:
a. Polarization
b. Association
c. Ionization
d. Electron transfer
Answer : C

Question. The values of dissociation constants of some acids (at 25°C) are as follows. Indicate which is the strongest acid in water?
a. 1.4x10⁻²
b. 1.6x10⁻⁴
c. 4.4x10⁻¹⁰
d. 4.3x10⁻⁷
Answer : A

Question. An example for a strong electrolyte is:
a. Urea
b. Ammonium hydroxide
c. Sugar
d. Sodium acetate
Answer : D

Question. The conjugate acid of HPO₃²⁻ is:
a. H₃PO₄
b. H₃PO₃
c. H₂PO₃⁻
d. PO₄³⁻
Answer : C

Question. 0.2 molar solution of formic acid is ionized 3.2%. Its ionization constant is:
a. 1×10⁻¹²
b. 2.1x10⁻⁴
c. 1.25x10⁻⁶
d. 1x10⁻¹⁴
Answer : B

Question. A monoprotic acid in 1.00 M solution is 0.01% ionised. The dissociation constant of this acid is:
a. 1x10⁻⁸
b. 1x10⁻⁴
c. 1x10⁻⁶
d. 5 10⁻⁵
Answer : A

Question. If α is the degree of ionization, C the concentration of a weak electrolyte and Ka the acid ionization constant, then the correct relationship between α, C and K_a is:

Answer : C

Question. Which one of the following can be classified as a Bronsted base?
a. NO₃⁻
b. H₃O⁺
c. NH₄⁺
d. CH₃COOH
Answer : A

Question. The strength of an acid depends on its tendency to:
a. Accept protons
b. Donate protons
c. Accept electrons
d. Donate electrons
Answer : B

Question. For the reaction in aqueous solution Zn²⁺ + X^- ⇌ ZnX⁺ the K_eq is greatest when X is:
a. F⁻
b. NO₃⁻
c. ClO₄⁻
d. I⁻
Answer : A

Question. In the equilibrium:
CH₃COOH + HF ⇌ CH₃COOH²⁺ + F⁻
a. F^– is the conjugate acid of CH₃COOH
b. F^– is the conjugate base of HF
c. CH₃COOH is the conjugate acid of CH₃COOH₂⁺
Answer : B

Question. With reference to protonic acids, which of the following statements is correct?
a. 3 PH is more basic than NH₃
b. 3 PH is less basic than NH₃
c. 3 PH is equally basic as NH₃
d. 3 PH is amphoteric while NH₃ is basic
Answer : B

Question. When 100 ml of 1M NaOH solution is mixed with 10 ml of 10 M H₂SO₄, the resulting mixture will be?
a. Acidic
b. Alkaline
c. Neutral
d. Strongly alkaline
Answer : A

Question. When FeCl₃ gets soluble in water, then its solution represents which of the characteristics?
a. Amphoteric
b. Acidic
c. Basic
d. Neutral
Answer : B

Question. Orthoboric acid in aqueous medium is:
a. Monobasic
b. Dibasic
c. Tribasic
d. All are correct
Answer : A

Question. Which one is Lewis acid?
a. Cl⁻
b. Ag⁺
c. C₂ H₅OH
d. S²⁻
Answer : B

Question. Let the solubility of an aqueous solution of Mg(OH)₂ be then its sp k is:
a. 4x³
b. 108x³
c. 27x⁴
d. 9x
Answer : A

Question. Dissociation of H₃PO₄ takes place in following steps:
a. 1
b. 2
c. 3
d.4
Answer : C

Question. The pKa for acid A is greater than pKa for acid B. The strong acid is:
a. Acid B
b. Acid A
c. Both A and B
d. Neither A nor B
Answer : A

Question. Which of the following can act both as Bronsted acid and Bronsted base?
a. Cl
b. HCO₃⁻
c. H₃O⁺
d. OH⁻
Answer : B

Question. 100ml of 0.2 M H₂SO₄ is added to 100ml of 0.2 M NaOH.
The resulting solution will be:
a. Acidic
b. Basic
c. Neutral
d. Slightly basic
Answer : A

Question. The solubility product of BaSO₄ at 25°C is 1.0×10^–9. What would be the concentration of H₂SO₄ necessary to precipitate BaSO₄ from a solution of 0.01M Ba²⁺ ions?
a. 10^–9
b. 10^–8
c. 10^–7
d. 10^–6
Answer : C

Question. On adding solid potassium cyanide to water:
a. pH will increase
b. pH will decrease
c. pH will not change
d. Electrical conductance will not change
Answer : A

Question. The pH of a 0.001M NaOH will be
a. 3
b. 2
c. 11
d. 12
Answer : C

Question. In which of the following salt hydrolysis takes place?
a. KCl
b. NaNO₃
c. CH₃COOK
d. K₂SO₄
Answer : C

Question. Which of the following 0.1M solution will contain the largest concentration of hydronium ions?
a. NaHCO₃
b. NH₄Cl
c. HCl
d. NH₃
Answer : C

Question. When solid potassium cyanide is added in water then
a. pH will increase
b. pH will decrease
c. pH will remain the same
d. Electrical conductivity will not change
Answer : A

Question. 20ml of 0.5 N HCl and 35ml of 0.1N NaOH are mixed.
The resulting solution will
a. Be neutral
b. Be basic
c. Turn phenolphthalein solution pink
d. Turn methyl orange red
Answer : C

Question. Which of the anhydrous salts when come in contact with water turns blue?
a. Ferrous sulphate
b. Copper sulphate
c. Zinc sulphate
d. Cobalt sulphate
Answer : B

Question. The species among the following, which can act as an acid and a base, is?
a. HSO₄⁻
b. SO₄²⁻
c. H₃O⁺
d. Cl⁻
Answer : A

Question. The solubility of CaF₂ is a moles/litre. Then its solubility product is:
a. s²
b. 4s³
c. 3s²
d. 3s³
Answer : B

Question. Given pH of a solution A is 3 and it is mixed with another solution B having pH 2. If both mixed then resultant pH of the solution will be:
a.3.2
b.1.9
c.3.4
d.3.5
Answer : B

Question. An acidic buffer solution can be prepared by mixing solution of
a. Ammonium acetate and acetic acid
b. Ammonium chloride and hydrochloric acid
c. Sulphuric acid and sodium sulphate
d. Acetic acid and sulphuric acid
Answer : A

Question. If pOH of a solution is 6.0, then its pH will
a. 6
b. 10
c. 8
d. 14
Answer : C

Question. As the temperature increases, the pH of a KOH solution
a. Will decreases
b. Will increases
c. Remains constant
d. Depends upon concentration of KOH solution
Answer : A

Question. pH value of N/10 NaOH solution is
a. 10
b. 11
c. 12
d. 13
Answer : D

Question. A certain buffer solution contains equal concentration of X^– and HX. The Kb for X^– is 10^–10. The pH of the buffer is
a. 4
b. 7
c. 10
d. 14
Answer : A

Question. A physician wishes to prepare a buffer solution at pH = 3.58 that efficiently resists changes in pH yet contains only small concentration of the buffering agents. Which of the following weak acids together with its sodium salt would be best to use
a. m–chlorobenzoic acid (pK_a = 3.98)
b. p–chlorocinnamic acid (pK_a = 4.41)
c. 2, 5– dihydroxy benzoic acid (pK_a = 2.97)
d. Acetoacetic acid (pK_a = 3.58)
Answer : C

Question. What will be the pH of a solution formed by mixing 40 ml of 0.10 M HCl with 10 ml of 0.45 M 0.45 NaOH
a. 12
b. 10
c. 8
d. 6
Answer : A

Question. The pH of water at 25°C is nearly
a. 2
b. 7
c. 10
d. 12
Answer : B

Question. Which will have maximum pH?
a. Distilled water
b. 1M NH₃
c. 1M NaOH
d. Water saturated by chlorine
Answer : C

Question. The dissociation constant of an acid HA is 1×10^–5. The pH of 0.1 molar solution of the acid will be
a. Five
b. Four
c. Three
d. One
Answer : C

Question. What will be the pH of a 10^–8 M HCl Solution?
a. 8.0
b. 7.0
c. 6.98
d. 14.0
Answer : C

Question. An aqueous solution of sodium carbnate has a pH greater than 7 because:
a. It contains more carbonate ions than H₂O molecules
b. Contains more hydroxide ions than carbonate ions
c. Na⁺ ions react with water
d. Carbonate ions react with H₂O
Answer : B

1. Define strong and weak electrolyte.

2. Write the conjugate acids for the following Bronsted bases : NH₂, NH₃ and HCOO^-.

3. Which conjugate base is stronger CN^- or F^- ?

4. Give two examples of actions which can act as hour’s acids.

5. What is the difference between a conjugate acid and a conjugate base?

6. Select Lewis acid and Lewis base from the following : Cu²⁺ , H₂O, BF₃ OH^-

7. Predict if the solutions of the following salts are neutral, acidic or basic :

NaCl, KBr, NaCN, NaOH H₂SO₄, NaNO₂, NH₄ NO₃, KF

8. Justify the statement that water behaves like an acid and also like a base on the basis of protonic concept. 

Click on link below to download CBSE Class 11 Ionic Equilibrium In solution Worksheet A.