MCQs of Chemical Kinetics

Chemical Kinetics MCQs

MCQs of Chemical Kinetics

Showing 181 to 190 out of 228 Questions

181.

Which of the following equation is incorrect ?

(a)	$\log \frac{K}{A} = \frac{- E_{a}}{2.303 R T}$
(b)	$E_{a} = \frac{2.303 R \times T_{1} \times T_{2}}{T_{2} - T_{1}} \times \log \frac{K_{2}}{K_{1}}$
(c)	$A = K \times e^{\frac{- E_{a}}{R T}}$
(d)	$\ln A = \ln K - \frac{E_{a}}{2.303 R T}$

182.

Which statement is wrong with respect to activated complex ?

(a)	It possesses maximum potential energy.
(b)	It is short lived.
(c)	When it decomposes, it always forms product.
(d)	It breaks fact because its bonds are weak.

183.

The value of threshold energy for exothermic reactions is _____ .

(a)	energy of product + ΔH_reaction
(b)	energy of product + total energy of reactants
(c)	energy of product + reaction energy + E_a of forward reaction
(d)	energy of activated complex - E'_a of reverse reaction

184.

Which statement is correct with respect to activation energy?

(a)	The value of activation energy indicates the speed of forward or backward reaction but it does not indicate how much the reaction (proportion of the reaction) is completed.
(b)	If E_a of = 0, every reactant in the reaction, is capable of crossing the energy barrier, Hence such reactions are very speedy.
(c)	Every reaction has typical value of activation energy.
(d)	All of the above

185.

What is wrong statement for the equation

K = A \times e^{\frac{- E_{a}}{R T}}

(a)	Units of K and A are identical.
(b)	Effect of temperature is the same on K and A both.
(c)	E_a is not affected of T increases.
(d)	Slope of $\ln K \to \frac{1}{T}$ is $- \frac{E_{a}}{R}$ .

186.

Which of the following is most consistent relation ?

(a)	$Reaction rate \propto \frac{1}{Energy barrier} \propto Activation energy \propto Effective collisions$
(b)	$Reaction rate \propto \frac{1}{Energy barrier} \propto \frac{1}{Activation energy} \propto Effective collisions$
(c)	$Reaction rate \propto \frac{1}{Energy barrier} \propto \frac{1}{Activation energy} \propto \frac{1}{Effective collisions}$
(d)	$Reaction rate \propto \frac{1}{Energy barrier} \propto Activation energy \propto \frac{1}{Effective collisions}$

187.

Activation energy of forward and backward non catalysed reactions are x and x' respectively. If they are done using catalyst the activation energy if forward and backward reactions are y and y' respectively, then which of the following relation is true ?

(a)	x - x' > y - y'
(b)	x - x' = y - y'
(c)	x - x' < y - y'
(d)	x - x' ≤ y - y'

188.

If temperature of a reaction is increased from 27°C to 47°C, its rate constant becomes 4 times. Activation energy = _____ . ( R = 2 cal)

(a)	$2.303 \times 2 \times 300 \times 320 \times \log 4$
(b)	$\frac{2.303 \times 300 \times 320 \times 2}{20} \times \log 4$
(c)	$20 \times 2.303 \log 4$
(d)	$\frac{2.303 \times 2 \times 20}{300 \times 320} \times \log 4$

189.

For a reaction straight line obtained due to plot of

\log K \to \frac{1}{T}

has slope =

- 6.42 \times 10^{3}

cal. Its E_a = _____ .

(a)	$\frac{- 6.42 \times 10^{3} \times 2.303}{1.987}$
(b)	$\frac{6.42 \times 10^{3}}{2.303 \times 1.987}$
(c)	$6.42 \times 10^{3} \times 2.303 \times 1.987$
(d)	$- 6.42 \times 10^{3} \times 2.303 \times 1.987$

190.

According to rate constant

K = A \times e^{\frac{- E_{a}}{R T}}

, to increase the value of K = _____ .

(a)	T should be increased
(b)	E_a should be increased.
(c)	T should be decreased
(d)	$E_{a} \propto \infty$ and T = R

Showing 181 to 190 out of 228 Questions