If -239,- 116 and -286 kJ mol-1 respectively. The enthalpy c

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 Multiple Choice QuestionsMultiple Choice Questions

141.

Given that,

C (s) + O2 (g) → CO2 (g) ; H° = -x kJ mol-1

2CO (g) + O2 (g) → 2CO2 (g) ; H° = -y kJ mol-1

The enthalpy of formation of CO will be

  • y - 2x3

  • y - 2x2

  • 2x - y2

  • x - y2


142.

Which of the following relation is correct?

  • H = G + TS

  • H = -G - TS

  • H = G - TS

  • H = -G + TS


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143.

If -239,- 116 and -286 kJ mol-1 respectively. The enthalpy change for the oxidation of methanol to formaldehyde and water in kJ is

  • - 136

  • - 173

  • 163

  • -163


D.

-163

Give Hf° for CH3OH= - 239 kJ mol-1HCHO = -116 kJ mol-1H2O = - 286 kJ mol-1Required relation2CH3OH + O2  2 HCHO  + 2H2OHR= 12 Hf° of HCHO andH2OHR= 12 Hf° [ (2x - 116) + (2X - 286)] - 1 [(2 × 239)]= 12 [ (-232) + (-572)]-[-478]= 12[-804+ 478]= 12[-326] = -163 kJ mol-1


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144.

For an endothermic reaction where ΔH represents the enthalpy of the reaction in kJ/mol, the minimum value for the energy of activation will be

  • less than ΔH 

  • Zero

  • more than ΔH 

  • equal to ΔH 


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145.

Which of the following does not result in an increase in entropy?

  • Crystallisation of sucrose form a solution

  • Rusting of iron

  • Conversion of ice ofwater

  • Vaporisation of camphor


146.

In an adiabatic process which of the following is true?

  • q = +W

  • q = 0

  • E = q

  • pV = 0


147.

Equation log K2K1 = H2.303 R T2 -T1T1 . T2, n is

  • van der Waals' equation

  • Kirchoffs equation

  • Gas equation

  • van't Hoff equation


148.

Which of the following is true for a reaction in which all the products are liquid?

  • H = E

  • H = W

  • H > E

  • None of these


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149.

Cell reaction is spontaneous when

  • G° is negative

  • G° is positive

  • Ered° is positive

  • Ered° is negative


150.

At 27°C latent heat of fusion of a compound is 2930 J/ mol, then entropy change is

  • 9.77 J/mol-K

  • 10.77 J/ mol-K

  • 9.07 J/ mol-K

  • 0.977 J/ mol-K


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