Please refer to Equilibrium MCQ Questions Class 11 Chemistry below. These MCQ questions for Class 11 Chemistry with answers have been designed as per the latest NCERT, CBSE books, and syllabus issued for the current academic year. These objective questions for Equilibrium will help you to prepare for the exams and get more marks.
Equilibrium MCQ Questions Class 11 Chemistry
Please see solved MCQ Questions for Equilibrium in Class 11 Chemistry. All questions and answers have been prepared by expert faculty of standard 11 based on the latest examination guidelines.
MCQ Questions Class 11 Chemistry Equilibrium
Question. What is the best description of the change that occurs when Na2O(s) is dissolved in water?
(a) Oxidation number of sodium decreases
(b) Oxide ion accepts sharing in a pair of electrons
(c) Oxide ion donates a pair of electrons
(d) Oxidation nwnber of oxygen increases
Answer
C
Question. At a certain temperature, the dissociation constants of formic acid and acetic acid are 1.8 x 10-4 and 1.8 x l0-5, respectively. The concentration of acetic acid solution in which the hydrogen ion has the same concentration as in 0.001 M fomlic acid solution is equal to
(a) 0. 01 M
(b) 0. 001 M
(c) 0. lM
(d) 0. 0001M
Answer
A
Question. Diacidic base is
(a) CH2(OH)2
(b) Ca(OH)2
(c) CH3CH(OH)2
(d) All of these
Answer
B
Question. Which is Lewis acid?
(a) BF3
(b) NF3
(c) CI–
(d) H2O
Answer
A
Question. A weak monobasic acid is 1 % ionised in 0.1 M solution at 2S’C. The percentage of ionisation in its 0.025 M solution is
(a) 1
(b) 2
(c) 3
(d) 4
Answer
B
Question. Which of the following is the weakest acid?
(a) HCl
(b) HF
(c) H2SO4
(d) HNO3
Answer
B
Question. According to hard and soft acid-base principle, a hard acid
(a) has low charge density
(b) shows preference for soft bases
(c) shows preference for donor atoms of low electronegativity
(d) is not polarisable
Answer
D
Question. Four species are listed below
I. HCO–3
II. H3O+
III. HSO4
IV. HSO3F
Which one of the following is the correct sequence of their acid strength ?
(a) IV < II < III < I
(b) II < III < I < IV
(c) I < III < II < IV
(d) III < I < IV < II
Answer
C
Question. Three reactions involving H2PO–4 are given below
I. H3PO4 + H2O → H3O+ + H2PO–4
II. H2PO–4 + H2O → HPO2-4+ H3O+
III. H2PO–4 + OH– → H3PO4 + O2-
In which of the above does H2PO–4 act as an acid?
(a) Only II
(b) Both I and II
(c) Only III
(d) Only I
Answer
A
Question. Which of the following behaves as Lewis acid and not as Bronsted acid?
(a) HCl
(b) H2SO4
(c) HSO3
(d) SO3
Answer
D
Question. Which one of the following is the weakest acid?
(a) HF
(b) HCl
(c) HBr
(d) HI
Answer
A
Question. Which of the following acid is stronger than benzoic acid (Ka = 6.3 X 10-5)?
(a) A (Ka = 1.67 x 10-8)
(b) B (pKa = 6.0)
(c) C (pKa = 4.0)
(d) D (Ka = 1.0 x 10-5)
Answer
C
Question. For a diprotic acid, which of the following is true for 1st and 2nd ionisation constants (Ka1 and Ka2) ?
(a) Ka1 = Ka2
(b) Ka1 > Ka2
(c) Ka2 > Ka1
(d) Ka2 ≥ Ka1
Answer
B
Question. Water is well known amphoprotic solvent. In which chemical reaction, water is behaving as a base ?
(a) H2SO4 + H2O → H3O+ + HSO–4
(b) H2O + H2O → H3O+ + OH–
(c) H2O + NH2 → NH3 + OH–
(d) H2O + NH3 → NH+4+ OH–
Answer
A
Question. Which one of the following species acts as both Bronsted acid and base ?
(a) H2PO–2
(b) HPO2-3
(c) HPO2-4
(d) All of these
Answer
C
Question. Which of the following is a Lewis acid ?
(a) Cl–
(b) H3O+
(c) PF3
(d) C2H5OH
Answer
B
Question. For a concentrated solution ofa weak electrolyte AxBY of concentration C, the degree of dissociation ‘a.’ is given as
(a) a = √Keq /C(x+ y)
(b) a = √Keq /C(xy)
(c) a = (Keq /Cx+y-1 xX yY)1/(x + y)
(d) a = (Keq /Cxy)
Answer
C
Question. Conjugate acid of HF–2 is
(a) H+
(b) HF
(c) F–2
(d) H2F2
Answer
D
Question. Some chemists at ISRO wished to prepare a saturated solution of a silver compound and they wanted it to have the highest concentration of silver ion possible. Which of the following compounds, would they use?
Ksp(AgCl) = 1.8 x 10-10
Ksp(AgBr) = 5.0 x 10-13
Ksp(Ag2CrO4) = 2.4 x 10-12
(a) AgCl
(b) AgBr
(c) Ag2CrO4
(d) None of these
Answer
C
Question. Solubility of Al(OH)3 = s,Ksp will be
(a) 108S3
(b) 27S3
(c) 4S4
(d) 27S4
Answer
D
Question. Amines behave as
(a) Lewis acid
(b) Lewis base
(c) aprotic acid
(d) neutral compound
Answer
B
Question. Which of the following is not a conjugate acid-base pair?
(a) HPO3-3, PO3-3
(b) H2PO–4, HPO2-4
(c) H3PO4 , H2PO4
(d) H2PO–4, PO3-3
Answer
D
Question. According to Bronsted and Lowry , the strength of an acid depends upon
(a) the tendency to gain electrons
(b) the tendency to loss protons
(c) the tendency to accept protons
(d) the tendency to loss electrons
Answer
B
Question. Which is a Lewis base?
(a) B2H6
(b) LiAIH4
(c) AIH3
(d) NH3
Answer
D
Question. The solubility of Agl in Nal solution is less than that in pure water because
(a) the temperature of the solution decreases
(b) solubility product of AgI is less than that ofNal
(c) of common ion effect
(d) Agl forms complex with Nal
Answer
C
Question. The solubility product of a sparingly soluble salt AX 2 is 3.2 x 10-11 . Its solubility (in mol/L) is
(a) 5.6 X 10-6
(b) 3.1 X 10-4
(c) 2 X 10-4
(d) 4 X 10-4
Answer
C
Question. If solubility of calcium hydroxide is ✓3, then its solubility product will be
(a) 27
(b) 3
(c) 9
(d) 12✓3
Answer
D
Question. The solubility product of BaCl2 is 4 x 10-9 . Its solubility (in mol/L) is
(a) 4 x 10-3
(b) 4 x 10-9
(c) 1 x 10-3
(d) 1 x 10-9
Answer
C
Question. The molar solubility (in mo! L-1) of a sparingly soluble salt MX 4 is ‘s’. The corresponding solubility product is K ,sp. Sis given in terms of Ksp by the relation
(a) S = (Ksp 1/ 28)1/4
(b) S = (128 Ksp )1/4
(c) S = (256 Ksp )1/5
(d) S = (Ksp / 256)1/5
Answer
D
Question. The value of the ionic product of water depends
(a) on volume of water
(b) on temperature
(c) changes by adding acid or alkali
(d) always remain constant
Answer
B
Question. When ammonium chloride is added to ammonia solution, the pH of the resulting solution will be
(a) increased
(b) seven
(c) decreased
(d) unchanged
Answer
C
Question. The solubility in water of a sparingly soluble salt AB2 is 1.0 x 10-5 mol L-1 . Its solubility product number will be
(a) 4 x 10-15
(b) 4 X 10-10
(c) 1 X 10-15
(d) 1 X 10-10
Answer
A
Question. The Ksp of Ca3(PO4)2 his
(a) [Ca2+] [PO3-4]2
(b) [Ca2+]3 [PO3-4]
(c) [Ca2+] [PO3-4]
(d) [Ca2+]3 [PO3-4]2
Answer
D
Question. The solubility of CaF2 is pure water is 2.3 x 10-6 mol dm-3. Its solubility product will be
(a) 4.8 x 10-18
(b) 48.66 x 10-18
(c) 4.9 x 10-11
(d) 48.66 x 10-15
Answer
B
Question. At 90°C, pure water has H3O+ ion concentration of 10-6 mol / L-1 . The Kw at 90°C is
(a) 10-6
(b) 10-14
(c) 10-12
(d) 10-8
Answer
C
Question. A precipitate of AgCI is formed when equal volumes of the following are mixed.
[ K sp for AgCI = 10-10]
(a) 10-4 M AgNO3 and 10-7 M HCI
(b) 10-5 MAgNO3 and 10-6 MHCI
(c) 10-5 M AgNO3 and 10-4 M HCI
(d) 10-6 M AgNO3 and 10-6 M HCI
Answer
C
Question. The correct expression for the solubility product of Ca3 (PO4)2 is
(a) 108s5
(b) 27s5
(c) 16s4
(d) 81s4
Answer
A
Question. The solubility product of a salt having general formula MX 2 , in water is 4 x 10-2 . The concentration of M2+ ions in the aqueous solution of the salt is
(a) 4.0 x 10-10 M
(b) 1.6 x 10-4 M
(c) 1.0 x l0-4 M
(d) 2.0 x 10-3
Answer
C
Question. On adding 0.1 M solution each of [Ag+], [Ba2+],[Ca2+] in a Na2SO4 solution, species first precipitated is (Ksp BaSO4 = 10-11 ,Ksp CaSO4 = 10-6, Ksp AgSO4 =10-5)
(a) Ag2SO4
(b) BaSO4
(c) CaSO4
(d) All of the above
Answer
A
Question. The solubility of Pb(OH)2 in water is 6.7 x 10-6M. Its solubility in a buffer solution of pH = 8 would be
(a) 1.2 x 10-2
(b) 1.6 x 10-3
(c) 1.6 x 10-2
(d) 1.2 x 10-3
Answer
D
Question. For which of the following sparingly soluble salt, the solubility (s)and solubility product (Ksp)are related by the expressions= (Ksp / 4 )1/3 ?
(a) BaSO4
(b) Ca3 (PO4)2
(c) Hg2Cl2
(d) Ag3PO4
Answer
C
Question. The solubility of Sb2S3 in water is 1.0 x 10-5 mol / L at 298 K. What will be its solubility product ?
(a) 108 x 10-25
(b)1.0 x 10-25
(c) 144 x 10-25
(d) 126 x 10-24
Answer
A
Question. The first and second dissociation constants of an acid H2A are 1.0 x 10-5 and 5. 0 x 10-10 , respectively. The overall dissociation constant of the acid will be
(a) 5.0 x 10-5
(b) 5.0 x 1015
(c) 5.0 x 10-15
(d) 0.2 x 105
Answer
C
Question. Conjugate base of H2PO–4 is
(a) H3PO4
(b) P2O5
(c) PO3-4
(d) HPO2-4
Answer
D
Question. If for N2 + 3H2 ⇌ 2NH3 ,Keq = 1.6x 10-5 ,thenthe value of Keq for the reaction NH3 ⇌ 1/2N2 + 3/2 H2will be
(a) 6.25
(b) 25
(c) 250
(d) 500
Answer
C
Question. 3 moles of A and 4 moles of B are mixed together and allowed to come into equilibrium according to the following reaction.
3A (g) + 4B (g) ⇌ 2C (g) + 3D (g)
When equilibrium is reached, there is I mole of C. The equilibrium extent of the reaction is
(a) 1/ 4
(b) 1/3
(c) 1/2
Answer
C
Question. For the following three reactions I, II and m, equilibrium constants are given
I. CO (g) + H2O(g) ⇌ CO2(g)+ H2(g),K1
II CH4(g)+ H2O(g) ⇌ CO(g) + 3H2(g),K2
III. CH4(g)+ 2H2O(g) ⇌ CO2(g) + 4H2(g),K3
Which of the following relations is correct?
(a) K1 √K2 = K3
(b) K2 K3 = K1
(c) K3 = K1 K2
(d) K3 K32 = K12
Answer
C
Question. The equilibrium constants KPi and KPi for the reactions X ⇌ 2Y and Z ⇌ P + Q, respectively are in the ratio of 1 : 9. If the degree of dissociation of X and Z be equal, then the ratio of total pressure at these equilibria is
(a) 1 : 36
(b) 1 : 1
(c) 1 : 3
(d) 1 : 9
Answer
A
Question. In a 500 mL flask, the degree of dissociation of PCl5 at equilibrium is 40% and the initial amount is 5 moles. The value of equilibrium constant (in mol L-1 ) for the decomposition of PCl5 is
(a) 2.33
(b) 2.66
(c) 5.32
(d) 4.66
Answer
B
Question. Formaldehyde polymerises to fom1 glucose according to the reaction, 6HCHO ⇌ C6H12O6 .
The theoretically computed equilibrium constant for this reaction is found to be 6 x 1022 . If I M solution of glucose dissociates according to the above equilibrium, the concentration of formaldehyde in the solution will be
(a) 1.6x 10-2 M
(b) 1.6x 10-4 M
(c) 1.6 x 10-6 M
(d) 1.6 x 10-8 M
Answer
B
Question. 1n chemical equilibrium, the value of Δn (number of molecules of products – number of molecules of reactants), is negative, then the relationship between KP and Kc will be
(a) Kp – Kc = 0
(b) Kp = Kc(RT)+Δmg
(c) Kp = Kc(RT)-Δm
(d) Kp = KC
Answer
C
Question. Three moles of PCl5 , three moles of PCl3 and two moles of Cl2 are taken in a closed vessel. If at equilibrium, the vessel has 1.5 moles of PCl5 , the number of moles of PCl3 present in it is
(a) 5
(b) 3
(c) 6
(d) 4.5
Answer
D
Question. 2Hl (g) ⇌ H2 (g) + l2 (g) – QkJ
For the above reaction, equilibrium constant depends upon
(a) temperature
(b) pressure
(c) catalyst
(d) volume
Answer
A
Question. 1.6 moles of PCl5 (g) is placed in 4 dm3 closed vessel. When the temperature is raised to 500 K, it decomposes and at equilibrium, 1.2 moles of PCl5 (g) remains. What is the Kc value for the decomposition of PCl5 (g) into PCl3 (g) and Cl2 (g) at 500 K ?
(a) 0.013
(b) 0.050
(c) 0.033
(d) 0.067
Answer
C
Question. CO (g) + 1/2 O2 (g ) → CO2 (g) For the above reaction in gaseous phase, the value of KP / Kc is
(a) (RT)1/2
(b) (RT)-1/2
(c) (RT)
(d) (RT)-1
Answer
B
Question. In the reaction, H2( g) + Cl2(g) ⇌ 2HCl (g ),
(a) Kp ≠ Kc
(b) Kp = Kc
(c) Kp > Kc
(d) Kp < Kc
Answer
B
Question. 1 mole of H2 and 2 moles of I2 are taken initially in a 2 L vessel. The number of moles of H2 at equilibrium is 0.2. Then, the number of moles of I2 and HI at equilibrium respectively are
(a) 1.2, 1.6
(b) 1.8, 1.0
(c) 0.4, 2.4
(d) 0.8, 2.0
Answer
A
Questionuestion. Ammonium carbonate decomposes as
NH2COONH4(s) ⇌ 2 NH3 (g) + CO2 (g)
For the reaction, KP = 2.9 x 10-5 atm3 . If we start with 1 mole of the compound, the total pressure at equilibrium would be
(a) 0.766 atm
(b) 0.0581 atm
(c) 0.0388 atm
(d) 0.0194 atm
Answer
B
Question. The equilibrium constant (KP) for the decomposition of gaseous H2O as
H2O(g) ⇌ H 2 (g) + 1/2 O2 (g)
is related to degree of dissociation (a) at a total pressure p is given by
(a) Kp = a3 p1/2/(1 + α) (2 + α)1/2
(b) Kp = a3 p3/2/(1 – α) (2+α)1/2
(c) Kp = a3/2 p2/(1 – α) (2 + α)1/2
(d) Kp = a3 p1/2/(1 – α) (2+ α)1/2
Answer
D
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 the above
Answer
A
Question. At 600° C,K P for the following reaction is 1 atm.
X(g) ⇌ Y(g)+ Z(g)
At equilibrium, 50% of X ( g) is dissociated. The total pressure of the equilibrium system is p atm. What is the partial pressure (in atm) of X (g) at equilibtium?
(a) 1
(b) 4
(c) 2
(d) 0.5
Answer
A
Question. Which one of the following substances has the highest proton affinity ?
(a) H2O
(b) H2S
(c) NH3
(d) PH3
Answer
C
Question. Which is a Lewis base?
(a) B2H6
(b) LiAIH4
(c) AIH3
(d) NH3
Answer
D
Question. In Lowry-Bronsted concept, H+ donor is known as
(a) acid
(b) base
(c) Both (a) and (b)
(d) None of these
Answer
A
Question. An example of a Lewis acid is
(a) MgCI2
(b) SnCI4
(c) AICI3
(d) NaCI
Answer
C
Question. Which of the following is a Lewis base ?
(a) NaOH
(b) NH3
(c) BCI3
(d) All of these
Answer
B
Question. The ionisation of strong compared to water, is
(a) weak, low
(b) strong, more
(c) medium, the same electrolytes in acetic acid,
(d) no ionisation, 100%
Answer
A
Question. An acid solution of 0.005 M has a pH of 5. The degree of ionisation of acid is
(a) 0.1 x 10-2
(b) 0.2 x 10-2
(c) 0.5 x 10-4
(d) 0.6 x 10-6
Answer
B
Question. Strongest conjugate base is
(a) CIO–
(b) ClO–2
(c) ClO–3
(d) ClO–4
Answer
A
Question. What kind of molecule AICI3 is?
(a) Bronsted acid
(b) Lewis acid
(c) Lewis base
(d) Bronsted base
Answer
B
Question. Which of the following is a Lewis acid?
(a) AICI3
(b) Cl–
(c) CO
(d) C2H2
Answer
A
Question. Ammge NH+4 , H2O, H3O+, HF and Off in increasing order of acidic nature
(a) H3O+ < NH+4 < HF < OH– < H2O
(b) NH+4! < HF < H3O+ < H2O < OH–
(c) OH– < H2O < NH+4 < HF < H3O+
(d) H3O+> HF > H2O > NH+4> OH–
Answer
C
Question. Which one of the following is not an amphoteric substance ?
(a) HNO3
(b) HCO–3
(c) H2O
(d) NH3
Answer
A
Question. Conjugate acid of S2O-28 is
(a) H2S2O8
(b) H2SO4
(c) HS2O–8
(d) HSO–4
Answer
C
Question. CH3COOH is weaker acid than H2SO4 . It is due to
(a) more ionisation
(b) less ionisation
(c) covalent bond
(d) electrovalent bond
Answer
B
Question. What is the conjugate base of OH– ?
(a) O2-
(b) O–
(c) H2O
(d) O2
Answer
A
Question. The values of dissociation constant of bases are given below. Which is the weakest base?
(a) 1.8 X 10-5
(b) 4.8 X 10-10
(c) 7.2 X 10-11
(d) 7.07 x 10-7
Answer
C
Question. The species among the following, which can act as an acid and a base is
(a) HSO–4
(b) SO2-4
(c) H3O+
(d) Cl–
Answer
A
Question. The pH of a neutral water sample is 6. 5. Then, the temperature of water
(a) is 25°C
(b) is more than 25°C
( c) is less than 25°C
(d) can be more or less than 25°C
Answer
B
Question. On mixing equal volumes of two buffer solutions of pH value 3 and 5, the pH of the resultant solution will be
(a) 3.3
(b) 4.0
(c) 4.7
(d) 5.3
Answer
A
Question . Which of the following is not a Lewis acid ?
(a) BF3
(b) AICI3
(c) SO2
(d) H2O
Answer
D
Question . Which is a Lewis base?
I2 + I– → I–3
(a) I2
(b) I–3
(b) I–
(d) None of these
Answer
C
Question . The conjugate acid of NH–2 is
(a) N2H4
(b) NH+4
(c) NH2OH
(d) NH3
Answer
D
Question . Ostwald’s dilution law is applicable for
(a) weak electrolyte
(b) strong electrolyte
(c) both weak and strong electrolyte
(d) non-electrolyte
Answer
A
Question . Metal ions like Ag+, Cu2+ etc., act as
(a) Bronsted acids
(b) Bronsted bases
(c) Lewis acids
(d) Lewis bases
Answer
C
Question . If 200 mL of a 0.031 molar solution of H2SO4 are added to 84 mL of a 0.150 M KOH solution, what is the value of pH of the resulting solution?
(a) 12.4
(b) 1.7
(c) 2.2
(d) 10.9
Answer
D
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