A plot of ln K against 1T (abscissa) is expected to be a str

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

41.

For isothermal expansion of an ideal gas, the correct combination of the thermodynamic parameters will be

  • U = 0; Q = 0; W ≠ 0 and H ≠  0

  • U ≠ 0; Q ≠ 0; W ≠ 0 and H =  0

  • U = 0; Q ≠ 0; W = 0 and H ≠  0

  • U = 0; Q ≠ 0; W ≠ 0 and H =  0


42.

The standard Gibbs free energy change (G°) at 25°C for the dissociation of N2O4(g) to NO2(g) is (given, equilibrium constant = 0.15, R = 8.314 JK/mol)

  • 1.1 kJ

  • 4.7 kJ

  • 8.1 kJ

  • 38.2 kJ


43.

The condition of spontaneity of a process is

  • lowering of entropy at constant temperature and pressure

  • lowering of Gibbs free energy of system at constant temperature and pressure

  • increase of entropy of system at constant temperature and pressure

  • increase of Gibbs free energy of the universe at constant temperature and pressure


44.

Identify the correct statement from the following in a chemical reaction

  • The entropy always increases

  • The change in entropy along with suitable change in enthalpy decides the rate of reaction

  • The enthalpy always decreases

  • Both the enthalpy and the entropy remain constant


Advertisement
Advertisement

45.

A plot of ln K against 1T (abscissa) is expected to be a straight line with intercept on ordinate axis equal to

  • S°2.303 R

  • S°R

  • -S°R

  • R × S°


B.

S°R

G° = -RT ln K

or, H° -TS° =-RTln K

or, ln K = -H°RT + S°R

Comparing with y = mx + c

y (intercept) is S°R


Advertisement
46.

Which of the following is correct?

  • Evaporation of water causes an increase in disorder of the system

  • Melting of ice causes a decrease in randomness of the system

  • Condensation of steam causes an increase in disorder of the system

  • There is practically no change in the randomness of the system when water is evaporated


47.

In which of the following reactions will U be equal to H?

  • H2(g) +12O2(g)H2O(l)

  • H2(g) + I2(g)  2HI(g)

  • N2O4(g)  2NO2(g)

  • 2SO4(g) + O2(g)  2SO3(g)


48.

For the reaction

N(g) + 3H2 (g)  2NH3 (g) H is equal to

  • E - 2RT

  • E - RT

  • E + RT

  • E + 2RT


Advertisement
49.

Given, G°=-nFE°cell and G° = -RT ln k. The value of n = 2 will be given by the slope of which line in the figure

  • OA

  • OB

  • OC

  • OD


50.

The standard molar heat of formation of ethane, CO2 and water (l) are respectively -21.1, -94.1 and -68.3 kcal. The standard molar heat of combustion of ethane will be

  • -372 kcal

  • 162 kcal

  • -240 kcal

  • 183.5 kcal


Advertisement