NEW
New Website Launch
Experience the best way to solve previous year questions with mock tests (very detailed analysis), bookmark your favourite questions, practice etc...
1

AIPMT 2015 Cancelled Paper

MCQ (Single Correct Answer)
When initial concentration of a reactant is doubled in a reaction, its half-life period is not affected. The order of the reaction is
A
second
B
more than zero but less than first
C
zero
D
first.

Explanation

Half-life period of a first order reaction is independent of initial concentration,

$${t_{{1 \over 2}}} = {{0.693} \over k}$$
2

AIPMT 2015 Cancelled Paper

MCQ (Single Correct Answer)
The activation energy of a reaction can be determined from the slope of which of the following graphs?
A
ln k vs. $${1 \over T}$$
B
$${T \over {\ln \,k}}$$ vs. $${1 \over T}$$
C
ln k vs. $$T$$
D
$${{\ln k} \over T}$$ vs. $$T$$

Explanation

According to Arrhenius equation,

$$k = A{e^{ - {{{E_a}} \over {ET}}}}$$

Taking natural log on both the sides we get,

ln k = ln A $${ - {{{E_a}} \over {ET}}}$$ ...........(1)

Comparing (1) with standard form of equation of line

y = mx + C

We get Slope, m = $${ - {{{E_a}} \over R}}$$

Hence, if ln k is plotted against 1/T, slope of the line will be $${ - {{{E_a}} \over R}}$$.
3

AIPMT 2015

MCQ (Single Correct Answer)
The rate constant of the reaction A $$ \to $$ B is 0.6 $$ \times $$ 10$$-$$3 mol L$$-$$1 s$$-$$1. If the concentration of A is 5 M, then concentration of B after 20 minutes is
A
3.60 M
B
0.36 M
C
0.72 M
D
1.08 M

Explanation

For zero order reaction unit of rate constant is mole per second.

$$ \therefore $$ For zero order

x = kt

$$ \Rightarrow $$ x = 0.6 × 10–3 × 20 × 60 = 0.72 M
4

NEET 2013 (Karnataka)

MCQ (Single Correct Answer)
A reaction is 50% complete in 2 hours and 75% complete in 4 hours. The order of reaction is
A
1
B
2
C
3
D
0

Explanation

For a first order reaction,

t75% = 2 $$ \times $$ t50%

Joint Entrance Examination

JEE Main JEE Advanced WB JEE

Graduate Aptitude Test in Engineering

GATE CSE GATE ECE GATE EE GATE ME GATE CE GATE PI GATE IN

Medical

NEET

CBSE

Class 12