Please refer to the MCQ Questions for Class 11 Chemistry Chapter 7 Equilibrium with Answers. The following Equilibrium Class 11 Chemistry MCQ Questions have been designed based on the latest syllabus and examination pattern for Class 11. Our experts have designed MCQ Questions for Class 11 Chemistry with Answers for all chapters in your NCERT Class 11 Chemistry book.
Equilibrium Class 11 MCQ Questions with Answers
See below Equilibrium Class 11 Chemistry MCQ Questions, solve the questions and compare your answers with the solutions provided below.
Question. Equal volumes of three acid solutions of pH 3, 4 and 5 are mixed in a vessel. What will be the H+ ion concentration in the mixture?
(a) 3.7 × 10–3 M
(b) 1.11 × 10–3 M
(c) 1.11 × 10–4 M
(d) 3.7 × 10–4 M
Question. A weak acid, HA, has a Ka of 1.00 × 10–5. If 0.100 mol of this acid is dissolved in one litre of water, the percentage of acid dissociated at equilibrium is closest to
Question. Which statement is wrong about pH and H+?
(a) pH of neutral water is not zero.
(b) Adding 1 N solution of CH3COOH and 1 N solution of NaOH, pH will be seven.
(c) [H+] of dilute and hot H2SO4 is more than concentrated and cold H2SO4.
(d) Mixing solution of CH3COOH and HCl, pH will be less than 7.
Question. The concentration of [H+] and concentration of [OH–] of a 0.1 aqueous solution of 2% ionised weak acid is [ionic product of water = 1 × 10–14]
(a) 2 × 10–3 M and 5 × 10–12 M
(b) 1 × 10–3 M and 3 × 10–11 M
(c) 0.02 × 10–3 M and 5 × 10–11 M
(d) 3 × 10–2 M and 4 × 10–13 M
Question. The hydride ion H– is stronger base than its hydroxide ion OH–. Which of the following reaction will occur if sodium hydride (NaH) is dissolved in water?
(a) H– + H2O → no reaction
(b) H (aq) + H2O → H2O
(c) H (aq) + H2O(l) → OH– + H2
(d) None of these.
Question. The pH value of N/10 NaOH solution is
Question. The pH value of a 10 M solution of HCl is
(a) equal to 1
(b) equal to 2
(c) less than 0
(d) equal to 0
Question. At 80°C, distilled water has [H3O+] concentration equal to 1 × 10–6 mole/litre. The value of Kw at this temperature will be
(a) 1 × 10–12
(b) 1 × 10–15
(c) 1 × 10–6
(d) 1 × 10–9
Question. 0.1 M solution of which one of these substances will act basic?
(a) Sodium borate
(b) Ammonium chloride
(c) Calcium nitrate
(d) Sodium sulphate
Question. The compound whose water solution has the highest pH is
Question. The ionic product of water at 25°C is 10–14. Its ionic product at 90°C will be,
(a) 1 × 10–14
(b) 1 × 10–16
(c) 1 × 10–20
(d) 1 × 10–12
Question. If a is dissociation constant, then the total number of moles for the reaction, 2HI → H2 + I2 will be
(b) 1 – α
(d) 2 – α
Question. The dissociation constant of a weak acid is 1 × 10–4. In order to prepare a buffer solution with a pH = 5, the [Salt]/[Acid] ratio should be
(a) 4 : 5
(b) 10 : 1
(c) 5 : 4
(d) 1 : 10
Question. Buffer solutions have constant acidity and alkalinity because
(a) these give unionised acid or base on reaction with added acid or alkali
(b) acids and alkalies in these solutions are shielded from attack by other ions
(c) they have large excess of H+ or OH– ions
(d) they have fixed value of pH.
Question. A buffer solution is prepared in which the concentration of NH3 is 0.30 M and the concentration of NH4 + is 0.20 M. If the equilibrium constant, Kb for NH3 equals 1.8 × 10–5, what s the pH of this solution? (log 2.7 = 0.43)
Question. In a buffer solution containing equal concentration of B– and HB, the Kb for B– is 10–10. The pH of bufferolution is
Question. Which will make basic buffer?
(a) 100 mL of 0.1 M HCl + 100 mL of 0.1 M NaOH
(b) 50 mL of 0.1 M NaOH + 25 mL of 0.1 M CH3COOH
(c) 100 mL of 0.1 M CH3COOH + 100 mL of 0.1 M NaOH
(d) 100 mL of 0.1 M HCl + 200 mL of 0.1 M NH4OH
Question. Which one of the following pairs of solutions is not an acidic buffer?
(a) CH3COOH and CH3COONa
(b) H2CO3 and Na2CO3
(c) H3PO4 and Na3PO4
(d) HClO4 and NaClO4
Question. An acid HA ionises as, HA ⇌ H+ + A– The pH of 1.0 M solution is 5. Its dissociation constant would be
(a) 1 x 10-10
(c) 5 x 10-8
(d) 1 x 10-5
Question. 0.023 g of sodium metal is reacted with 100 cm3 of water. The pH of the resulting solution is
Question. pH value of which one of the following is not equal to one?
(a) 0.1M HN03
(b) 0.05 M H2SO4
(c) 0. lM CH3COOH
(d) 50 cm3 of 0.4 M HCl + 50cm3 of 0.2 M NaOH
Question. A solution [H3O+] is 10-4 . The solution is
Question. The pH of 10-10 M NaOH solution is nearest to
(a) – 4
(b) – 10
Question. The pH value of 0.00 l M aqueous solution of NaCl is
Question. A solution contains 10 mL of 0.1 N NaOH and 10 mL of 0.05 N H2SO4 ,pH of this solution is
(a) less than 7
(d) greater than 7
Question. 30 cc of M/3 HCl, 20 cc of M/2 HNO3 and 40 cc of M/4 NaOH solutions are mixed and the volwne was made upto 1 dm3 . The pH of the resulting solution is
Question. 10-6 M NaOH is diluted 100 times. The pH of the diluted base is
(a) between 7 and 8
(b) between 5 and 6
(c) between 6 and 7
(d) between 10 and 11
Question. When 200 mL of aqueous solution of HCl (pH = 2) is mixed with 300 mL of an aqueous solution of NaOH (pH= 12) the pH of the resulting mixture is
Question. An aqueous solution whose pH is zero will be called as
Question. Which of the following acids will have lowest value of pKa ?
Question. The pH values of 0.1 M solution of HCl, CH3COOH, NH4Cl and CH3COONa will have the order
(a) HCI < CH3COOH < NH4Cl < CH3COONa
(b) CH3COONa < NH4Cl < CH3COOH < HCI
(c) NH4Cl < CH3COONa < CH3COOH < HCI
(d) All will have same of pH value
Question. A weak acid HX has dissociation constant 10-5 . The pH of 0.1 M solution ofthis acid will be
Question. 50 mL of H2O is added to 50 mL of 1 x 10-3 M barium hydroxide solution. What is the pH of the resulting solution?
Question. Which of the following pairs constitutes a buffer?
(a) HCl and KCl
(b) HNO2 and NaNO2
(c) NaOH and NaCl
(d) HNO3 and NH4NO3
Question. Solution of 0.1 N NH4OH and 0.1 N NH4Cl has pH 9.25. Then find out pKb of NH4OH.
Question. A physician wishes to prepare a buffer solution at pH = 3.85 that efficiently resists changes in pH yet contains only small concentration of the buffering agents. Which of the ollowing weak acids together with its sodium salt would be best to use?
(a) 2, 5-Dihydroxybenzoic acid (pKa = 2.97)
(b) Acetoacetic acid (pKa = 3.58)
(c) m-Chlorobenzoic acid (pKa = 3.98)
(d) p-Chlorocinnamic acid (pKa = 4.41)
Question. The molar solubility of CaF2 (Ksp = 5.3 × 10–11) in 0.1 M solution of NaF will be
(a) 5.3 × 10–11 mol L–1
(b) 5.3 × 10–8 mol L–1
(c) 5.3 × 10–9 mol L–1
(d) 5.3 × 10–10 mol L–1
Question. The solubility of BaSO4 in water is 2.42 × 10–3 g L–1 at 298 K. The value of its solubility product (Ksp) will be (Given molar mass of BaSO4 = 233 g mol–1)
(a) 1.08 × 10–10 mol2 L–2
(b) 1.08 × 10–12 mol2 L–2
(c) 1.08 × 10–14 mol2 L–2
(d) 1.08 × 10–8 mol2 L–2
Question. Concentration of the Ag+ ions in a saturated solution of Ag2C2O4 is 2.2 × 10–4 mol L–1. Solubility product of Ag2C2O4 is
(a) 2.66 × 10–12
(b) 4.5 × 10–11
(c) 5.3 × 10–12
(d) 2.42 × 10–8
Question. The solubility of AgCl(s) with solubility product 1.6 × 10–10 in 0.1 M NaCl solution would be
(a) 1.26 × 10–5 M
(b) 1.6 × 10–9 M
(c) 1.6 × 10–11 M
Question. MY and NY3, two nearly insoluble salts, have the same Ksp values of 6.2 × 10–13 at room temperature. Which statement would be true in regard to MY and NY3?
(a) The salts MY and NY3 are more soluble in 0.5 M KY than in pure water.
(b) The addition of the salt of KY to solution of MY and NY3 will have no effect on their solubilities.
(c) The molar solubilities of MY and NY3 in water are identical.
(d) The molar solubility of MY in water is less than that of NY3.
Question. pH of a saturated solution of Ca(OH)2 is 9. The solubility product (Ksp) of Ca(OH)2 is
(a) 0.5 × 10–10
(b) 0.5 × 10–15
(c) 0.25 × 10–10
(d) 0.125 ×10–15
Question. The Ksp of Ag2CrO4, AgCl, AgBr and AgI are respectively, 1.1 × 10–12, 1.8 × 10–10, 5.0 × 10–13, .3 × 10–17. Which one of the following salts will precipitate last if AgNO3 olution is added to the solution containing equal moles of NaCl, NaBr, NaI and Na2CrO4?
Question. The solubility product of a sparingly soluble salt AX2 is 3.2 × 10–11. Its solubility (in moles/L) is
(a) 5.6 × 10–6
(b) 3.1 × 10–4
(c) 2 × 10–4
(d) 4 × 10–4
Question. The solubility product of AgI at 25°C is 1.0 × 10–16 mol2 L–2. The solubility of AgI in 10–4 N solution of KI at 25°C is approximately (in mol L–1)
(a) 1.0 × 10–16
(b) 1.0 × 10–12
(c) 1.0 × 10–10
(d) 1.0 × 10–8
Question. Solubility of MX2 type electrolytes is 0.5 × 10–4 mol/lit., then find out Ksp of electrolytes.
(a) 5 × 10–12
(b) 25 × 10–10
(c) 1 × 10–13
(d) 5 × 10–13
Question. Solubility of M2S salt is 3.5 × 10–6 then find out solubility product.
(a) 1.7 × 10–6
(b) 1.7 × 10–16
(c) 1.7 × 10–18
(d) 1.7 × 10–12
Question. Identify the correct order of solubility in aqueous medium.
(a) Na2S > CuS > ZnS
(b) Na2S > ZnS > CuS
(c) CuS > ZnS > Na2S
(d) ZnS > Na2S > CuS
Question. 4 moles each of SO2 and O2 gases are allowed to react to form SO3 in a closed vessel. At equilibrium, 25% of 0 2 is used up. The total number of moles of all the gases at equilibriun1 is
Question. For an equilibriun1 reaction, N2O4 (g) ⇌ 2NO2 (g ), the concentrations of N2O4 and NO2 at equilibrium are 4.8 x 10-2 and 1.2 x 10-2 mol/L, respectively. The value of Kc for the reaction is
(a) 3 x 10-3 mol/L
(b) 3.3 x 10-3 mol/L
(c) 3 x 10-1 mol/L
(d) 3.3 x 10-1 mol/L
Question. Equivalent amounts of H2 and I2 are heated in a closed vessel till equilibrium is obtained. If 80% of the hydrogen can be converted to HI, the valve of Kc at this temperature is
Question. For the reaction H2 (g) + I2 (g) → 2HI (g ), the equilibriun1 constant KP changes with
(a) total pressure
(c) the amount of HI and I2
Question. A + B ⇌ C + D. If initially the concentration of both A and B are both equal but at equilibrium, concentration of D will be twice of that of A, then what will be the equilibrium constant of reaction?
Question. The equilibrium constant for the reaction.
2NO2 (g) ⇌ 2NO(g) + O2 (g) is 2 x 10-6 at 185°C
Then the equilibrium constant for the reaction,
4NO(g) + 2O2 (g) ⇌ 4NO2 (g) at the same
temperature would be
(a) 2.5 X 10-5
(b) 4 X 10-12
(c) 2.5 X 1011
(d) 2 x 106
Question. A liquid is in equilibrium with its vapour at its boiling oint. On the average, the molecules in two phases have equal
(a) intermolecular forces
(b) potential energy
(c) kinetic energy
(d) total energy
Question. In the reaction 3A + 2B → 2C, the equilibriumconstant Kc is given by
(a) [3A] x [2B] / [C]
(b) [A]3 x[B] / [C]
(c) [C]2 [A]3 x[B]2
(d) [C] / [3A][2B]
Question. N2 and H2 in l : 3 molar ratio are heated in a closed container having a catalyst. When the following equilibrium, N2 (g) + 3H2 (g) ⇌ 2NH3 (g) is attained, the total pressure is 10 atm and mole fraction of NH3 is 0.60. The equilibrium constant KP for dissociation of NH3 is
(a) 1.333 atm-2
(b) 0.75 atm2
(c) 0.75 atm-2
(d) 1.333 atm2
Question. P4 (s) + 5O2 (g) ⇌ P4O10 (s)
What is the equilibrium expression for the above reaction?
(a) Kc = [P4O10] / [P4][O2]5
(b) Kc = [P4O10] / 5[P4][O2]
(c) Kc = [O2]5
(d) Kc = 1 / [O2]5
Question. CO(g) + 0.5O2 (g) → CO2 (g)
For the above reaction KP/Kc is equal to
Question. Consider the reactions
NO2 ⇌ 1/2 N2 + O2 ,K1 and N2O4 ⇌ 2NO2 ,K2
Give the equilibrium constant for the fom1ation of N2O4 from N2 and O2.
(a) 1/K21 x 1/K2
(d) K2 / K1
Question. The equilibrium constant for the reaction,
SO2 (g) + 1/2 O2(g) ⇌ SO3(g) is 5 x 10-2 atm. The equilibrium constant of the reaction
2SO3 (g) ⇌ 2SO2 (g) + O2 (g) would be
(a) 100 atm
(b) 200 atm
(c) 4 x 102 atm
(d) 6.25 x 104 atm
Question. By applying law of mass action, the equilibrium constant K for the reaction
HA + H2O ⇌ H3O+ + A–, is given as
(a) K = [HA][H2O] / [HH3O+][A–]
(b) K = [H3O+][A–] / [HA] [H2O]
(c) K = [H3O+] [H2O] / [A–] [HA]
(d) K = [HA][A–] / [H2O][H3O+]
Question. Ag+ + NH3 ⇌ [Ag (NH3 )+ ,K1 = 3.5 x 10-3
[Ag(NH3)+ + NH3 ⇌ [Ag(NH3)2]+
K 2 = 1.7x 10-3
Then the formation constant of [Ag(NH3 )2]+ is
(a) 6.08 x 10-6
(b) 6.08 X 106
(c) 6.08 x 10-9
(d) None of these
Question. For the reaction H2 + I2 ⇌ 2HI, the equilibrium concentration of H2, I2 and Hl are 8.0, 3.0 and 28.0 mol/L, respectively. The equilibrium constant is
Question. Phosphorus pentachloride dissociates as follows, in a closed reaction vessel,
PCl5 (g) ⇌ PCl3(g)+Cl2 (g)
If total pressure at equilibrium of the reaction mixture is p and degree of dissociation of PCl5 is x, then the partial pressure of PCl3 will be
(a) (x /x + 1)p
(b) (2x / 1 – 2)P
(c) (x / 1 – x)P
(d) (x / 1 – x)p
Question. pH of a saturated solution of Ba(OH)2 is 12. The value of solubility product (Ksp) of Ba(OH)2 is
(a) 3.3 × 10–7
(b) 5.0 × 10–7
(c) 4.0 × 10–6
(d) 5.0 × 10–6
Question. The solubility of a saturated solution of calcium fluoride is 2 × 10–4 moles per litre. Its solubility product is
(a) 22 × 10–11
(b) 14 × 10–4
(c) 2 × 10–2
(d) 32 × 10–12
Question. The solubility of AgCl will be minimum in
(a) 0.01 M CaCl2
(b) pure water
(c) 0.001 M AgNO3
(d) 0.01 M NaCl
Question. Which one of the following is most soluble?
(a) Bi2S3 (Ksp = 1 × 10–70)
(b) Ag2S (Ksp = 6 × 10–51)
(c) CuS (Ksp = 8 × 10–37)
(d) MnS (Ksp = 7 × 10–16)
Question. The pH value of blood does not appreciably change by a small addition of an acid or a base, because the blood
(a) can be easily coagulated
(b) contains iron as a part of the molecule
(c) is a body fluid
(d) contains serum protein which acts as buffer
Question. Which of the following is not a general characteristic of equilibria involving physical processes ?
(a) Equilibrium is possible only in a closed system at a given temperature.
(b) All measurable properties of the system remain constant.
(c) All the physical processes stop at equilibrium.
(d) The opposing processes occur at the same rate and there is dynamic but stable condition.
Question. The liquid which has a ………..vapour pressure is more volatile and has a ………….boiling point.
(a) Higher , higher
(b) Lower, lower
(c) Higher, lower
(d) Lower, higher
Question. Boiling point of the liquid depends on the atmospheric pressure. It depends on the altitude of the place; at high altitude the boiling point…………..
(c) either decreases or increases
(d) remains same
Question. In an experiment three watch glasses containing separately 1mL each of acetone, ethyl alcohol, and water are exposed to atmosphere and the experiment with different volumes of the iquids in a warmer room is repeated, it is observed that in all such cases the liquid eventually disappears and the time taken for complete evaporation in each case was different. The ossible reason is/are
(a) the nature of the liquids is different
(b) the amount of the liquids is different
(c) the temperature is different
(d) All of the above
Question. A small amount of acetone is taken in a watch glass and it is kept open in atmosphere. Which statement is correct for the given experiment?
(a) The rate of condensation from va
(b) The rate of condensation from vapour to liquid state is equal to the rate of evaporation.
(c) The rate of condensation from vapour to liquid state is much less than the rate of evaporation.
(d) The rate of condensation from vapour to liquid state is equal or less than the rate of evaporation.
Question. The reaction quotient Q is used to
(a) predict the extent of a reaction on the basis of its magnitude
(b) predict the direction of the reaction
(c) calculate equilibrium concentrations
(d) calculate equilibrium constant
Question. A reaction is said to be in equilibrium when
(a) the rate of transformation of reactant to products is equal to the rate of transformation of products to the reactants.
(b) 50% of the reactants are converted to products.
(c) the reaction is near completion and all the reactants are converted to products.
(d) the volume of reactants is just equal to the volume of the products.pour to liquid state is higher than the rate of evaporation.
Question. Which of the following is not true about a reversible reaction?
(a) The reaction does not proceed to completion
(b) It cannot be influenced by a catalyst
(c) Number of moles of reactants and products is always equal
(d) It can be attained only in a closed container
Question. If the synthesis of ammonia from Haber’s process is carried out with exactly the same starting conditions (of partial pressure and temperature) but using D2 (deuterium) in place of 2. Then
(a) the equilibrium will be disturbed
(b) the composition of reaction mixture will remain same at equilibrium.
(c) Use of isotope in reaction will not produce ammonia.
(d) At equilibrium rate of forward reaction will be greater than the rate of reverse reaction
Question. If a system is at equilibrium, the rate of forward to the reverse reaction is :
(d) at equilibrium
Question. In a reversible chemical reaction having two reactants in equilibrium, if the concentration of the reactants are doubledthen the equilibrium constant will
(a) Also be doubled
(b) Be halved
(c) Become one-fourth
(d) Remain the same
Question. On doubling P and V with constant temperature the equilibrium constant will
(a) remain constant
(b) become double
(c) become one-fourth
(d) None of these