MCQs of Chemical Kinetics

Chemical Kinetics MCQs

MCQs of Chemical Kinetics

Showing 91 to 100 out of 228 Questions

91.

The value of the rate constant for a first order reaction is 2.303×10^-2 sec^-1.What will be the time required to reduce the concentration to

\frac{1}{10} th

of its initial concentration ?

(a)	10 second
(b)	100 second
(c)	2303 second
(d)	230.3 second

92.

The rate constant of the reaction A → B is 0.6 × 10^-3 mole per second. if the concentration of A is 5 M,then concentration of B after 20 minutes is :

(a)	0.36 M
(b)	0.72 M
(c)	1.08 M
(d)	3.60 M

93.

What will be the theoretical rate of elementary reaction if pressure of O₂ is increased by three times ? 2SO_2(g) + O_2(g) → 2SO_3(g)

(a)	27 times increase
(b)	9 times increase
(c)	18 times increase
(d)	3 times increase

94.

For the reaction A + B → Products,

- \frac{d [A]}{dt} = x . e^{- \frac{E_{a}}{RT}}

, what is x ?

(a)	Collision frequency.
(b)	Molecularity.
(c)	Avogadro number.
(d)	Rate constant.

95.

An elementary reaction occurs in a closed vessel. 2CO_(g)+O_2(g) → 2CO_2(g) If the volume of the reaction vessel is made one third of its original volume at constant temperature,the order of the reaction _____ of its original rate.

(a)	becomes twenty seven times
(b)	becomes nine times
(c)	becomes three times
(d)	becomes eighteen times

96.

Decomposition of H₂O₂ follows a first order reaction. In fifty minutes the concentration of H₂O₂ decreases from 0.5 to 0.125 M in one such decomposition. When the concentration of H₂O₂ reaches 0.05 M, the rate of formation of O₂ will be:

(a)	1.34×10^-2 mol min^-1
(b)	6.93 ×10^-2 mol min^-1
(c)	6.93 ×10^-4 mol min^-1
(d)	2.66 L min^-1 at STP

97.

For reaction :

3 X \to 2 Y

, which of the following will be equal to

\frac{d [Y]}{d t}

(a)	$- \frac{3}{2} \frac{d [X]}{d t}$
(b)	$\frac{3}{2} \frac{d [X]}{d t}$
(c)	$- \frac{1}{6} \frac{d [X]}{d t}$
(d)	$+ 3 \frac{d [X]}{d t}$

98.

For

N_{2} + 3 H_{2} \to 2 {NH}_{3}

if $\frac{- d [{NH}_{3}]}{d t} = 2 \times 10^{- 4} mole {litre}^{- 1} {second}^{- 1}$ , what will be the value of $- \frac{d [H_{2}]}{d t}$ ?

(a)	$6 \times 10^{- 4} mole {litre}^{- 1} {second}^{- 1}$
(b)	$1 \times 10^{- 4} mole {litre}^{- 1} {second}^{- 1}$
(c)	$3 \times 10^{- 4} mole {litre}^{- 1} {second}^{- 1}$
(d)	$4 \times 10^{- 4} mole {litre}^{- 1} {second}^{- 1}$

99.

Select the correct term for reaction rate for the reaction

2 N_{2} O_{5} \to 4 {NO}_{2} + O_{2}

(a)	$\frac{1}{2} \frac{d [N_{2} O_{5}]}{d t}$
(b)	$2 \frac{d [N_{2} O_{5}]}{d t}$
(c)	$\frac{1}{4} \frac{d [{NO}_{2}]}{d t}$
(d)	$4 \frac{d [{NO}_{2}]}{d t}$

100.

State correct term fro reaction rate for the reaction :

N_{2 (g)} + 3 H_{2 (g)} \to 2 {NH}_{3 (g)}

(a)	Reaction rate = $\frac{- d [N_{2}]}{d t} = \frac{- 1}{3} \frac{d [H_{2}]}{d t} = \frac{1}{2} \frac{d [{NH}_{3}]}{d t}$
(b)	Reaction rate = $\frac{- d [N_{2}]}{d t} = - 3 \frac{d [H_{2}]}{d t} = 2 \frac{d [{NH}_{3}]}{d t}$
(c)	Reaction rate = $\frac{d [N_{2}]}{d t} = \frac{1}{3} \frac{d [H_{2}]}{d t} = \frac{1}{2} \frac{d [{NH}_{3}]}{d t}$
(d)	Reaction rate = $\frac{- d [N_{2}]}{d t} = \frac{d [H_{2}]}{d t} = \frac{d [{NH}_{3}]}{d t}$

Showing 91 to 100 out of 228 Questions