New ! Chemistry MCQ Practise Tests



Important 1mark -chapter 7,8

11th Standard

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Chemistry

Use blue pen Only

Time : 00:50:00 Hrs
Total Marks : 50

    Answer all the questions

    50 x 1 = 50
  1. In a reversible process, the change in entropy of the universe is ____.

    (a)

    > 0

    (b)

    > 0

    (c)

    < 0

    (d)

    = 0

  2. The intensive property among the quantities below is ____________

    (a)

    mass

    (b)

    volume

    (c)

    enthalpy

    (d)

    \(\frac { mass }{ volume } \)

  3. The enthalpies of formation of Al2O3 and Cr2Oare -1596 kJ and -1134 kJ, respectively. ΔH for the reaction 2AI + Cr2O3 ⟶ 2Cr + Al2O3 is _______________

    (a)

    - 1365 kJ

    (b)

    2730 kJ

    (c)

    - 2730 kJ

    (d)

    - 462 kJ

  4. The value of ΔH for cooling 2 moles of an ideal monatomic gas from 125° C to 25° C at constant pressure will be [given C\(\frac{5}{2}\)R] ____________.

    (a)

    - 250 R

    (b)

    - 500 R

    (c)

    500 R

    (d)

    + 250 R

  5. When 15.68 litres of a gas mixture of methane and propane are fully combusted at 0° C and 1 atmosphere, 32 litres of oxygen at the same temperature and pressure are consumed. The amount of heat of released from this combustion in KJ is _____________ (ΔHc (CH4) = - 890 KJ mol-1 and ΔHc (C3H8 = - 2220 KJ mol-1)

    (a)

    - 889 kJ mol-1

    (b)

    - 1390 kJ mol-1

    (c)

    - 3180 kJ mol-1

    (d)

    - 635.47 kJ mol-1

  6. ΔS is expected to be maximum for the reaction ____________

    (a)

    Ca(S)+ 1/2O2(g) ⟶ CaO(S)

    (b)

    C(S) + O2(g) ⟶ CO2(g)

    (c)

    N2(g) + O2(g) ⟶ 2NO(g)

    (d)

    CaCO3(S) ⟶ CaO(S) + CO2(g)

  7. A portion of matter under consideration, which is separated from rest of universe by real or imaginary boundaries is called_____________

    (a)

    surroundings

    (b)

    system

    (c)

    boundary

    (d)

    Universe

  8. The process in which temperature of the system remains constant is called __________ process

    (a)

    isobaric

    (b)

    isothermal

    (c)

    adiabatic

    (d)

    isochoric

  9. Internal energy is denoted by the symbol_______

    (a)

    H

    (b)

    S

    (c)

    G

    (d)

    U

  10. Which among the following is a state function?

    (a)

    Pressure

    (b)

    Enthalpy

    (c)

    Heat

    (d)

    Both (a) and (b)

  11. Which among the following is a path function?

    (a)

    Enthalpy

    (b)

    Free energy

    (c)

    Internal energy

    (d)

    Work

  12. The SI unit of heat is ____________

    (a)

    Joule

    (b)

    Calorie

    (c)

    mole

    (d)

    J mol-1

  13. The gravitational work done by an object is __________

    (a)

    Qv

    (b)

    fx

    (c)

    PV

    (d)

    mgh

  14. In a compression process, Pext is ___________

    (a)

    (Pint+ dP)

    (b)

    (Pint- dP)

    (c)

    (dP-Pint)

    (d)

    (-Pint+dP)

  15. Identify the suitable condition(s) which helps the adiabatic process to occur?
    (i) ΔT = 0
    (ii)ΔP = 0
    (iii) q = 0
    (iv) w = 0

    (a)

    Only (i)

    (b)

    Only (iii)

    (c)

    (i) and (ii)

    (d)

    (i), (ii) and (iv)

  16. The heat of neutralisation of strong acid and strong base is __________

    (a)

    +57.32 KJ

    (b)

    +75.32 KJ

    (c)

    -75.32 KJ

    (d)

    -57.32 KJ

  17. In an exothermic reaction, heat is evolved and system loses heat to the surroundings. For such system
    (i) qp will be negative
    (ii) ΔrH will be positive
    (iii) qp  will be positive
    (iv) ΔrH will be negative

    (a)

    (i), (ii)

    (b)

    (iii), (iv)

    (c)

    (i) & (iv)

    (d)

    (ii) & (iii)

  18. For a given reaction \(\triangle\)G obtained was having positive sign convention. State whether the reaction was spontaneous or non-spontaneous.

    (a)

    spontaneous

    (b)

    non-spontaneous

    (c)

    reversible

    (d)

    equilibrium

  19. The condition for standard free energy is _______

    (a)

    298 K, 1 atm

    (b)

    273 K, 1 atm

    (c)

    2980 C, 5 atm

    (d)

    25 K, 1atm

  20. Solve: ΔH=10 k cal mol-1, ΔS=20 cal deg-1 mol-1 and T=300k. Then ΔG=?

    (a)

    -18,000 cals mol-1

    (b)

    18,000 cals mol-1

    (c)

    -16,000 cals mol-1

    (d)

    4000 cals mol-1

  21. When solid melts there is ____________

    (a)

    an increase of entropy

    (b)

    a decrease in entropy

    (c)

    an increase in free energy

    (d)

    an increase of heat of fusion

  22. An efficiency of an engine is always ____________

    (a)

    =0%

    (b)

    >100%

    (c)

    <100%

    (d)

    = 100%

  23. -\(\Delta\) G is the net work done by the system except ____________

    (a)

    Electrical work

    (b)

    Expansion work

    (c)

    Chemical work

    (d)

    Photo chemical work

  24. Entropy change involved in the conversion of 1 mole of liquid water at 373K to vapour at the same temperature will be (\(\Delta\)Hvap=2.257 kJg-1) ____________

    (a)

    0.119 kJ

    (b)

    0.109 kJ

    (c)

    0.129 kJ

    (d)

    0.120 kJ

  25. Which of the following units represent largest amount of energy?

    (a)

    calories

    (b)

    Joule

    (c)

    erg

    (d)

    eV

  26. Identify the state quantity among the following:

    (a)

    q

    (b)

    q-w

    (c)

    q+w

    (d)

    q/w

  27. Heat liberated when 100 ml of IN NaOH is neutralized by 300 ml of IN HCI __________

    (a)

    22.92 kJ

    (b)

    17.19 kJ

    (c)

    11.6 kJ

    (d)

    5.73 kJ

  28. In an adiabatic process, no transfer of heat takes place between the system and surroundings. Choose the convert option for free expansion of ideal gas under adiabatic conditions from the following:

    (a)

    q=0; \(\Delta\)\(\neq \)0; w = 0

    (b)

    q\(\neq \)0;\(\Delta\)T =0; w = 0

    (c)

    q = 0; \(\Delta\)T = 0; w = 0

    (d)

    q = 0; \(\Delta\)T < 0; w \(\neq \)0

  29. Two similar reactions are given below:
    H2(g)+\(\frac { 1 }{ 2 } \)O2(g) \(\rightarrow\)H2O(g); \(\Delta\)H = \(\Delta\)H1
    H2(g)+\(\frac { 1 }{ 2 } \)O2(g)\(\rightarrow\)H2O(l); \(\Delta\)H =  \(\Delta\)H2
    In terms of magnitude, of \(\Delta\)H

    (a)

    \(\Delta\)H1 > \(\Delta\)H2

    (b)

    \(\Delta\)H1 < \(\Delta\)H2

    (c)

    \(\Delta\)H1 = \(\Delta\)H2

    (d)

    cannot be predicted

  30. Which one of the following is an extensive property?

    (a)

    Molar volume

    (b)

    Density

    (c)

    Molarity

    (d)

    Entropy

  31. Which one of the following is an intensive property??

    (a)

    Specific heat capacity

    (b)

    Mass

    (c)

    Enthalpy

    (d)

    Heat capacity

  32. Thermodynamics is applicable to ________

    (a)

    macroscopic system only

    (b)

    microscopic system only

    (c)

    homogeneous system only

    (d)

    heterogeneous system only

  33. Which of the following properties is not a function of state?

    (a)

    Concentration

    (b)

    Internal energy

    (c)

    Enthalpy

    (d)

    Entropy

  34. For the process to occur under adiabatic conditions, the correct condition is __________ 

    (a)

    ΔT=0

    (b)

    ΔP=0

    (c)

    q=0

    (d)

    w=0

  35. The standard substance used in the enthalpy of combustion of a substance in bomb calorimeter is _______

    (a)

    methane

    (b)

    acetic acid

    (c)

    propane

    (d)

    benzoic acid

  36. If Kb and Kf for a reversible reactions are 0.8 x 10–5 and 1.6 x 10–4 respectively, the value of the equilibrium constant is __________

    (a)

    20

    (b)

    0.2 x 10-4

    (c)

    0.05

    (d)

    none of these

  37. The formation of ammonia from N2(g) and H2(g) is a reversible reaction
    N2(g) + 3H2(g) ⇌ 2NH3(g) + Heat
    What is the effect of increase of temperature on this equilibrium reaction ______________

    (a)

    equilibrium is unaltered

    (b)

    formation of ammonia is favoured

    (c)

    equilibrium is shifted to the left

    (d)

    reaction rate does not change

  38. Which one of the following is incorrect statement?

    (a)

    for a system at equilibrium, Q is always less than the equilibrium constant

    (b)

    equilibrium can be attained from either side of the reaction

    (c)

    presence of catalyst affects both the forward reaction and reverse reaction to the same extent

    (d)

    Equilibrium constant varied with temperature

  39. K1 and K2 are the equilibrium constants for the reactions respectively.
    \({ N }_{ 2 }(g)+{ O }_{ 2 }(g)\overset { { K }_{ 1 } }{ \rightleftharpoons } 2NO(g)\)
    \(2NO(g)+{ O }_{ 2 }(g)\overset { { K }_{ 2 } }{ \rightleftharpoons } { 2NO }_{ 2 }(g)\)
    What is the equilibrium constant for the reaction NO2(g) ⇌ ½N2(g) + O2(g)

    (a)

    \({1\over \sqrt{K_1K_2}}\)

    (b)

    (K1 = K2)1/2

    (c)

    \({1\over 2K_1K_2}\)

    (d)

    \(({1\over K_1K_2})^{3/2}\)

  40. In the equilibrium,
    2A(g) ⇌ 2B(g) + C2(g)
    the equilibrium concentrations of A, B and C2 at 400 K are 1\(\times\)10–4 M, 2.0 \(\times\)10–3 M, 1.5 \(\times\)10–4 M respectively. The value of KC for the equilibrium at 400 K is ________

    (a)

    0.06

    (b)

    0.09

    (c)

    0.62

    (d)

    3 x 10-2

  41. \({K_c\over K_p}\) for the reaction,
    N2(g) + 3H2(g) ⇌ 2NH3(g) is ___________

    (a)

    \({1\over RT}\)

    (b)

    \(\sqrt{RT}\)

    (c)

    RT

    (d)

    (RT)2

  42. For the reaction AB (g) ⇌ A(g) + B(g), at equilibrium, AB is 20% dissociated at a total pressure of P, The equilibrium constant KP is related to the total pressure by the expression __________

    (a)

    P = 24 KP

    (b)

    P = 8 KP

    (c)

    24 P = KP

    (d)

    none of these

  43. If x is the fraction of PCl5 dissociated at equilibrium in the reaction
    PCl5 ⇌ PCl3 + Cl2
    then starting with 0.5 mole of PCl5, the total number of moles of reactants and products at equilibrium is ___________

    (a)

    0.5 - x

    (b)

    x + 0.5

    (c)

    2x + 0.5

    (d)

    x + 1

  44. The values of KP1 and KP2 for the reactions
    X ⇌ Y + Z
    A ⇌ 2B are in the ratio 9 : 1 if degree of dissociation and initial concentration of X and A be equal then total pressure at equilibrium P1 and P2 are in the ratio __________

    (a)

    36 : 1

    (b)

    1 : 1

    (c)

    3 : 1

    (d)

    1 : 9

  45. In the reaction,
    Fe (OH)3 (s) ⇌ Fe3+(aq) + 3OH(aq),
    if the concentration of OH ions is decreased by ¼ times, then the equilibrium concentration of Fe3+ will

    (a)

    not changed

    (b)

    also decreased by ¼ times

    (c)

    increase by 4 times

    (d)

    increase by 64 times

  46. Consider the reaction where KP = 0.5 at a particular temperature
    PCl5(g) ⇌ PCl3 (g) + Cl2 (g)
    if the three gases are mixed in a container so that the partial pressure of each gas is initially 1 atm, then which one of the following is true ____________

    (a)

    more PCl3 will be produced

    (b)

    more Cl2 will be produced

    (c)

    more PCl5 will be produced

    (d)

    none of these

  47. In a chemical equilibrium, the rate constant for the forward reaction is 2.5 \(\times\)102 and the equilibrium constant is 50. The rate constant for the reverse reaction is ____________

    (a)

    11.5

    (b)

    5

    (c)

    2 x 102

    (d)

    2 x 10-3

  48. For the formation of Two moles of SO3(g) from SO2 and O2, the equilibrium constant is K1. The equilibrium constant for the dissociation of one mole of SO3 into SO2 and O2 is __________

    (a)

    \(1/K_1\)

    (b)

    \(K_1^2\)

    (c)

    \(({1\over K_1})^{1/2}\)

    (d)

    \({K_1\over 2}\)

  49. Consider the following reversible reaction at equilibrium, A + B ⇌ C, If the concentration of the reactants A and B are doubled, then the equilibrium constant will ___________

    (a)

    be doubled

    (b)

    become one fourth

    (c)

    be halved

    (d)

    remain the same

  50. The equilibrium constants of the following reactions are:

      N2 + 3H2 ⇌ 2NH3   :    K1 
      N2 + O2 ⇌ 2NO      :    K2
      H2 + ½O2 ⇌ H2O   :    K3

    The equilibrium constant (K) for the reaction ;
    \({ 2NH }_{ 3 }+5/2{ O }_{ 2 }\overset { K }{ \rightleftharpoons } 2NO+{ 3H }_{ 2 }{ O },\) will be

    (a)

    \(K_2^3{K_3\over K_1}\)

    (b)

    \(K_1{K_3^3\over K_2}\)

    (c)

    \(K_2{K_3^3\over K_1}\)

    (d)

    \(K_2{K_3\over K_1}\)

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