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.

Chemical Kinetics

Short Answer Type

81. Which of the reactions slow or fast, will have higher activation energy?

138 Views

82. What information can we had from the statement that the energy of activation of a reaction is zero?

121 Views

83. Define collision frequency factor.

186 Views

84. For the reaction H₂ + I₂ → 2HI, What is the molecularity of the reaction?

374 Views

85. Define the term ‘order of reaction’ for chemical reactions.

307 Views

86. The decomposition of dimethyl ether leads to the formation of CH₄, H₂ and CO and the rate is given by
Rate = k[CH₃OCH₃]^3/2
The rate of reaction is followed by increase in pressure in a closed vessel, so the rate can also be expressed in terms of the partial pressure of dimethyl ether, i.e.,
Rate = k pCH₃O CH₃^3/2.
If the pressure is measured in bar and time in minutes, then what are the units of rate and rate constants?

The reaction for decomposition of dimethyl ether can be written as

{CH}_{3} - O - {CH}_{3} \to {CH}_{4} + H_{2} + CO

The rate of reaction,

(\frac{dx}{dt}) = \frac{d ({CH}_{3} {OCH}_{3})}{dt} = \frac{d [{CH}_{4}]}{dt} = \frac{d [H_{2}]}{dt} \frac{d [CO]}{dt}

= k ({pCH}_{3} {OCH}_{3})^{3 / 2}

The unit of rate is: bar min^–1 or bar s^–1.
The unit of rate constant, k is bar s^–1 bar^–3/2

[∵ k = rate (pCH₃OCH₃)^–3/2∴ bar^–1/2 s^–1.

163 Views

87. List the factors on which the rate of a chemical reaction depends.

238 Views

Long Answer Type

88. From the rate expression for the following reactions, determine their order of reaction and the dimensions of the rate constants
(i) 3NO(g) → N₂O (g) Rate = k[NO]²
(ii) H₂O₂ (aq) + 3I^– (aq) + 2H⁺ → 2H₂O (l) + I^-₃Rate = k[H₂O₂][I^-]
(iii) CH₃CHO (g) → CH₄ (g) + CO(g) Rate = k [CH₃CHO]3/2
(iv) C₂H₅Cl (g) → C₂H₄ (g) + HCl (g) Rate = k [C₂H₅Cl]

205 Views

89. A reaction is second order with respect to a reactant. How is the rate of rection affected if the concentration of the reactant is
(i) Doubled
(ii) Reduced to 1/2?

222 Views

90. A reaction is first order in A and second order in B
(i) Write differential rate equation.
(ii) How is the rate affected when the concentration of B three times?
(iii) How is the rate affected when the concentrations of both A and B are doubled?

135 Views