Name: ______________________________________
Topic: Chemical Equilibrium
General Instructions:
1. There are 25 objective questions in which only one is correct.
2. Dark the given OMR Sheet with Blue /Black Ball pen.
3. Total time allotted is 90 minutes
4. There is overall no negative marking.
1. When pressure is applied to the equilibrium system
Ice ‡ ˆ † Water
ˆ ˆ
Which of the following phenomenon will happen?
(a) More ice will be formed (b) Water will evaporate
(c) More water will be formed (d) Equilibrium will not be formed
2. For the manufacture of ammonia by the reaction
N2 3H2 ‡ ˆ † 2NH3 2kcal
ˆ ˆ
the favorable conditions are
(a) Low temperature, low pressure and catalyst
(b) Low temperature, high pressure and catalyst
(c) High temperature, low pressure and catalyst
(d) High temperature, high pressure and catalyst
3. Of the following which change will shift the reaction towards the product?
I2 (g) ‡ ˆ † 2I(g),
ˆ ˆ H 150kJ
(a) Increase in concentration of I (b) Decrease in concentration of I2
(c) Increase in temperature (d) Increase in total pressure
4. Equilibrium constant for the reaction
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2NO(g) Cl2 (g) ‡ ˆ † 2NOCl(g)
ˆ ˆ
is correctly given by the expression
[2NOCl] [NOCl]2
(a) K (b) K
[2NO] [Cl2 ] [NO]2 [Cl2 ]
[NOCl]2 [NOCl]2
(c) K (d) K
[NO]2 [Cl2 ]2 [NO]2 [Cl2 ]
5. 2HCl(g) ‡ ˆ † H2 (g) Cl2 (g)
ˆ ˆ
For the above reaction, the equilibrium constant is 1.0 × 10 –5. If the equilibrium
concentration of H2 and Cl2 is 1.2 × 10–3 M and 1.2 × 10–4 M, respectively, then
the concentration of HCl is :
(a) 12 × 10–4 M (b) 12 × 10–3 M (c) 12 × 10–2 M (d) 12 × 10–1 M
1
6. The equilibrium constant of equilibrium SO2 O 2 ‡ ˆ † SO3
ˆ ˆ ˆ and
2
2SO2 O2 ‡ ˆ † 2SO3
ˆ ˆ
are K1 and K2 respectively. The relationship between K1 and K 2 is
(a) K2 = K1 (b) K2 = K12
1 1
(c) K 2 = (d) K 2
K1 K12
7. For
N2 3H2 ‡ ˆ † 2NH3 Heat
ˆ ˆ
(a) K p K c (b) K p K c RT
2 1
(c) Kp Kc (RT) (d) Kp Kc (RT)
8. At constant temperature, the equilibrium constant (Kp) for the decomposition
reaction N2 O4 (g) ‡ ˆ † 2NO2 (g) is expressed by Kp 4x2P /(1 x 2 ) where P is
ˆ ˆ
pressure, x is extent of decomposition. Which of the following statement is true ?
(a) Kp increases with increase of P
(b) Kp increases with increase of x
(c) Kp increases with decrease of x
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(d) Kp remain constant with change in P or x.
9. The equilibrium 2SO2 (g) + O2 (g) ‡ ˆ † 2SO3 (g) shifts forward if :
ˆ ˆ
(a) A catalyst is used
(b) An adsorbent is used to remove SO3 as soon as it is formed
(c) Large amounts of reactants are used
(d) Small amounts of reactants are used
10. In the precipitation of iron group in qualitative analysis, NH4Cl is added before
adding NH4OH to :
(a) Decrease concentration of OH ions
(b) Prevent interfering of PO 4 ions
(c) Increase concentration of Cl ions
(d) Increase concentration of NH 4 ions
11. The catalyst iron, employed in the Haber process, contains molybdenum, the
function of which is :
(a) To increase the rate of combination of gases
(b) To counterbalance for the presence of impurities in the gases
(c) To act as a catalyst promoter and increase its activities
(d) To make up for the adverse temperature
12. When a buffer solution, sodium acetate and acetic acid is diluted with water :
(a) Acetate ion concentration increases
(b) H+ ion concentration increases
(c) OH– ion conc. increases
(d) H+ ion concentration remains unaltered
13. The vapour density of PCl5 is 104.16 but when heated to 230°C its vapour density is
reduced to 62. The degree of dissociation of PCl5 at this temperature will be :
(a) 6.8% (b) 68% (c) 46% (d) 64%
14. An acid solution of 0.005 M has a pH of 5. The ionisation of acid is :
(a) 0.1 × 10–2 (b) 0.2 × 10–2
(c) 0.5 × 10–4 (d) 0.6 × 10–6
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15. The concentration of (H ) and concentration of (OH–) of a 0.1 M aqueous solution
and 2% ionised weak acid is
[ionic product of water = 1× 10 14 ]
(a) 0.02 × 10–3 M and 5 × 10–11 M.
(b) 2×10–3 M and 5× 10–12 M.
(c) 1 × 10–3 M and 3 × 10–11 M.
(d) 3 × 10–2 M and 4 × 10–13 M.
16. Which one of the following has minimum dissociation constant?
(a) CHCl2COOH (b) CH2ClCOOH (c) CH3COOH (d) CCl3COOH
17. Which of the following favours the reverse reaction in chemical equilibrium ?
(a) Increasing the concentration of the reactant
(b) Removal of at least one of the products at regular intervals
(c) Increasing the concentration of one or more of the product
(d) none of these.
18. The reaction quotient (Q) for the reaction
N2 (g) 3H2 (g) ‡ ˆ † 2NH3 (g)
ˆ ˆ
[NH 3 ]2
is given by Q = . The reaction will proceed from right to left if
[N 2 ][H 2 ]3
(a) Q < Kc (b) Q > Kc (c) Q=0 (d) Q = Kc
where Kc is the equilibrium constant.
19. A solution contains 10 ml of 0.1 N NaOH and 10 ml of 0.05 N H2SO4, pH of this
solution is
(a) 1 (b) Less than 7
(c) Greater than 7 (d) Zero
20. The pH of a buffer solution containing 25 ml of 1M CH3COONa and 25 ml of 1 M
CH3COOH will be appreciably affected by 5 ml of
(a) 1 M CH3COOH (b)5 M CH3COOH
(c) 5 M HCl (d) 1 M NH4OH
21. Which is the strongest Lewis base :
(a) SbH3 (b) AsH3 (c) PH3 (d) NH3
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22. Which of the following is conjugate base of [C2H5NH3]+
(a) C2H5NH2 (b) C2N+H4(OH)–
(c) [C2H2NH]– (d) None of these
23. Which equilibrium can be described as an acid-base reaction using the Lewis acid-
base definition but not using Bronsted and Lowery concept?
(a) NH3 CH3COOH ‡ ˆ † CH3COO
ˆ ˆ NH4
(b) H2 O CH3COOH ‡ ˆ † CH3COO
ˆ ˆ H2 O
(c) 4NH3 Cu2 ‡ ˆ † [Cu (NH3 )4 ]2
ˆ ˆ
(d) HCI CH3COOH ‡ ˆ † CH3COO
ˆ ˆ H2 Cl
24. The solubility product of lead chloride (PbCl2) at 20ºC is 1.5 × 10–4. It solubility is
(a) 3.34 × 102 (b) 3.34 × 104 (c) 3.34 × 10–2 (d) 3.34 × 10–4
25. At 25°C the value of Ki (equilibrium constant) for the reaction
1
N2 + O2 ‡ ˆ † N O2 , is 2 × 104
ˆ ˆ ....(i)
2
What will be the value of Kc for
2NO2 ‡ ˆ † N2 + 2 O2 ?
ˆ ˆ ....(ii)
1
(a) 2 × 104 (b) 8
(c) 2 × 102 (d) 104
4 10
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