A first-order reaction is 50% completed in 1.26 x 1014s. How much

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

301.

A first-order reaction has a specific reaction rate of 10–2 s–1. How much time will it take for 20 g of the reactant to reduce to 5 g?

  • 238.6 second

  • 138.6 second

  • 346.5 second

  • 346.5 second

1056 Views

302.

The equilibrium constants of the following are.

straight N subscript 2 space plus space 3 straight H subscript 2 space rightwards harpoon over leftwards harpoon with space on top space 2 NH subscript 3 space space straight K subscript 1
straight N subscript 2 space plus space straight O subscript 2 space rightwards harpoon over leftwards harpoon with space on top space 2 NO space space space space straight K subscript 2
straight H subscript 2 space plus space 1 half straight O subscript 2 space rightwards arrow with space on top space straight H subscript 2 straight O space straight K subscript 3

The equilibrium constant (K) of the reaction:

2 NH subscript 3 space plus space 5 over 2 straight O subscript 2 space rightwards harpoon over leftwards harpoon with straight K on top space 2 NO space plus space straight H subscript 2 straight O comma space will space be

  • straight K subscript 1 straight K subscript 3 superscript 3 divided by straight K subscript 2
  • straight K subscript 2 straight K subscript 3 superscript 3 space divided by space straight K subscript 1
  • straight K subscript 2 straight K subscript 3 superscript 3 space divided by space straight K
  • straight K subscript 2 straight K subscript 3 superscript 3 space divided by space straight K
1094 Views

303.

A mixture of 2.3 g formic acid and 4.5 g oxalic acid is treated with conc. H2SO4. The evolved gaseous mixture is passed through KOH pellets. Weight (in gram) of the remaining product at STP will be

  • 1.4

  • 3.0

  • 4.4

  • 2.8


304.

The correct difference between first and second order reactions is that

  • The rate of a first-order reaction does not depend on reactant concentrations; the rate of a second-order reaction does depend on reactant concentrations

  • The half-life of a first-order reaction does not depend on [A]0; the half-life of a second-order reaction does depend on [A]0

  • The rate of a first-order reaction does depend on reactant concentrations; the rate of a second-order reaction does not depend on reactant concentrations

  • A first-order reaction can catalyzed; a second-order reaction cannot be catalyzed


Advertisement
305.

When initial concentration of the reactant is doubled, the half-life period of a zero order reaction

  • Is halved

  • Is doubled

  • Remains unchanged

  • Is tripled


306.

For the chemical reaction,

2O3 ⇌ 3O2

The reaction proceeds as follows

O3 ⇌ O2 + O

O + O3 → 2O2 (slow)

The rate law expression will be

  • r = k' [O3]2

  • r = k' [O3]2[O2]-1

  • r = k'[O3][O2]

  • unpredictable


307.

In the following graph

The slope of line AB give the information of the

  • value of Ea2.303

  • Value of 2.303Ea

  • value of -Ea2.303

  • value of -Ea2.303 RT


Advertisement

308.

A first-order reaction is 50% completed in 1.26 x 1014s. How much time would it take for 100% completion?

  • 1.26 x 1015 s

  • 2.52 x 1014 s

  • 2.52 x 1028 s

  • Infinite


D.

Infinite

K- for the first order,

0.693t1/2 = 0.6931.26 x 1014 for 100% completion t = 2.303k log aa-xt = 2.303 x 1.26 x 10140.693 log 1000t = 


Advertisement
Advertisement
309.

For the chemical reaction, 2O3 ⇌ 3O2. The reaction proceeds as follows

O3 ⇌ O2 + O (fast)

O + O3 → 2O2 (slow)

The rate law expression will be

  • r = k'[O3]2

  • r = k'[O3]2[O2]-1

  • r = k'[O3][O2]

  • Unpredictable


310.

Two similar reactions have the same rate constant at 25°C, but at 35°C, one of the reaction has a higher rate constant than the other. The appropriate reason for this is

  • due to effective collisions

  • due to different activation energies

  • due to different threshold energies

  • due to higher population of molecules


Advertisement