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12th Standard Chemistry Ionic Equilibrium English Medium Free Online Test One Mark Questions 2020 - 2021

12th Standard

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Chemistry

Answer all the questions
Time : 00:20:00 Hrs
Total Marks : 20
    20 x 1 = 20
  1. Concentration of the Ag+ ions in a saturated solution of Ag2C2O4 is 2.24 ×10-4mol L-1 solubility product of Ag2C2O4 is

    (a)

    2.42 ×10-8mol3L-3

    (b)

    2.66 ×10-12mol3L-3

    (c)

    4.5 ×10-11mol3L-3

    (d)

    5.619 ×10-12mol3L-3

  2. Conjugate base for bronsted acids H2O and HF are

    (a)

    OH- and H2FH+ , respectively

    (b)

    H3O+ and F, respectively

    (c)

    OH- and F-, respectively

    (d)

    H3O+ and H2F+, respectively

  3. Which of the following fluro – compounds is most likely to behave as a Lewis base?

    (a)

    BF3

    (b)

    PF3

    (c)

    CF4

    (d)

    SiF4

  4. What is the decreasing order of strength of bases
    OH, NH2- H - C ≡ C and CH3 - CH2-

    (a)

    OH->NH2- >H-C≡C >CH3-CH2-

    (b)

    NH2->OH->CH3-CH2- >H-C≡C

    (c)

    CH3-CH2->NH2->H-C≡C->OH-

    (d)

    OH->H-C ≡ C->CH3-CH2- >NH2-

  5. The percentage of pyridine (C5H5N) that forms pyridinium ion (C5H5NH) in a 0.10M aqueous pyridine solution (Kb for C5H5N= 1.7×10-9) is

    (a)

    0.006%

    (b)

    0.013%

    (c)

    0.77%

    (d)

    1.6%

  6. The solubility of AgCl (s) with solubility product 1.6 ×10-10 in 0.1M NaCl solution would be

    (a)

    1.26 × 10-5M

    (b)

    1.6 ×10-9M

    (c)

    1.6 ×10-11M

    (d)

    Zero

  7. Using Gibb’s free energy change, ∆Go=57.34 kJ mol-1, for the reaction, X2Y(s)⇌2X++Y2- (aq), calculate the solubility product of X2Y in water at 300 K (R = 8.3 J K-1Mol-1)

    (a)

    10-10

    (b)

    10-12

    (c)

    10-14

    (d)

    can not be calculated from the given dat

  8. What is the pH of the resulting solution when equal volumes of 0.1M NaOH and 0.01M HCl are mixed?

    (a)

    2.0

    (b)

    3

    (c)

    7.0

    (d)

    12.65

  9. Which of the following can act as lowery – Bronsted acid well as base?

    (a)

    HCl

    (b)

    SO42−

    (c)

    HPO42−

    (d)

    Br-

  10. Dissociation constant of NH4OH is 1.8 x 10-5  the hydrolysis constant of NH4Cl would be

    (a)

    1.8 ×10-19

    (b)

    5.55 ×10-10

    (c)

    5.55 ×10-5

    (d)

    1.80 ×10-5

  11. HClis a strong acid since

    (a)

    It can be easily oxidised

    (b)

    It canbe easilyionised

    (c)

    It dissociates completely to give H+ ions in solution

    (d)

    It can be easily oxidised and It can be easilyionised

  12. Ionic product of water increases when

    (a)

    Pressure decreases

    (b)

    H+ ions are added

    (c)

    OH- ions are added

    (d)

    temperature increases

  13. An aqueous solution with pH value zero is

    (a)

    acidic

    (b)

    basic

    (c)

    amphoteric

    (d)

    neutral

  14. The pH of pure water at 25°C is

    (a)

    0

    (b)

    1

    (c)

    7

    (d)

    14

  15. pH of buffer depends upon concentration of

    (a)

    acid (H+)

    (b)

    Conjugate base (OH-)

    (c)

    Salt

    (d)

    acid (H+) and Conjugate base (OH-)

  16. The buffer present in human blood is

    (a)

    CH3COOH + CH3COONa

    (b)

    NH4OH + NH4CI

    (c)

    H2CO3 + H\({ CO }_{ 3 }^{ - }\)

    (d)

    CH3COOH + CH3COONa and NH4OH + NH4CI

  17. \({ X }_{ m }{ Y }_{ n(s) }\overset { { H }_{ 2 }O }{ \rightleftharpoons } { mX }_{ (aq) }^{ n+ }+{ nY }_{ (aq) }^{ m- }\)

    (a)

    \({ [{ X }^{ n+ }] }^{ m }{ [Y^{ m- }] }^{ n }\)

    (b)

    \({ [X }^{ n+ }][{ Y }^{ m- }]\)

    (c)

    \({ [{ X }^{ n+ }] }^{ m }/{ [Y^{ m- }] }^{ n }\)

    (d)

    \({ [X }^{ n+ }]/[{ Y }^{ m- }]\)

  18. When sodium acetate is added to acetic acid, the degree of ionisation of acetic acid

    (a)

    increases

    (b)

    decreases

    (c)

    dose not change

    (d)

    becomes zero

  19. Which one of the following formula represents Ostwald's dilution law for a binary whose degree of dissociation is a and concentration C.

    (a)

    \(K=\frac{(1-α)C}{α}\)

    (b)

    \(K=\frac{α^2C}{1-a}\)

    (c)

    K = \(\frac{(1-a)C}{a^2}\)

    (d)

    K = \(\frac{α^2C}{(1-α)c}\)

  20. Which one of the following relationship is correct?

    (a)

    \(pH=\frac { 1 }{ [{ H }^{ + }] } \)

    (b)

    \(pH={ log }_{ 10 }[{ H }^{ \\ + }]\)

    (c)

    \({ log }_{ 10 }pH=[{ H }^{ + }]\)

    (d)

    \(pH={ log }_{ 10 }\frac { 1 }{ [{ H }^{ + }] } \)

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