Test: JEE Previous Year Questions- Chemical Kinetics - JEE MCQ

For 10 degree rise in temperature, n = 1

so rate = 2ⁿ = 2¹ = 2

When temperature is increased from 10 deg C to 100 deg C change in temperature = 100-10 = 90 deg C i.e n=9 

so, rate = 2⁹ = 512 times.

The correct answer is option C
 3A ➡ 2B

Thus, the order of reaction with respect to A = 1
The order of reaction with respect to B =1
Total order of reaction = 1+1 = 2

The correct answer is option A
The unit of the rate constant K is (Molarity)¹⁻ⁿ time⁻¹.
Here, n is the order of the reaction.
For first order reaction, n=1.
The unit of the rate constant K is (Molarity)¹⁻¹sec⁻¹ = sec⁻¹.
For zero order reaction, n=0.
The unit of the rate constant K is (Molarity)¹⁻⁰sec⁻¹ =(Molarity)sec⁻¹ = (M) sec⁻¹.

The correct answer is option A
Compare straight line equation
(y = mx + c) with Kt = -log (Ct) + log(C0)
where,
K being constant,
"t" is equivalent to "y" in straight line equation
(-1) is slope for equation which is "m" in straight line equation
log (Ct) is x-component
& log (C0) is y-intercept.
 

The correct answer is Option C.
Unit of rate of reaction =sec⁻¹

∴ Units of K1 = sec⁻¹

∴ Unit of K₂ = M⁻¹sec⁻¹

In simpler words, after a certain period of time , Hydrogen is completely adsorbed on tungsten metal such that its surface becomes completely concentrated with Hydrogen thus the reaction becomes independent of concentration. a rxn independent of concentration is 0 order.

The correct answer is option A
In the Arrhenius Equation,
R is the gas constant.
k is the rate constant.
A is the frequency factor which is also known as Arrhenius factor.
Ea is the activation energy and it is the minimum amount of energy required for any reaction to proceed.
T is for temperature.

The correct answer is option A
rate=k[NO]₂[O₂]
As, C = n/V
On making the volume half, concentration doubles and rate of reaction becomes eight times.
 

The correct answer is Option B.

Rate =k[A]ⁿ[B]^m
          
When 
A'= 2A and
B'= 0.5B
 
The new rate becomes Rate' 
=[2A]ⁿ[0.5]^m

The correct answer is  Option A.
The concentration of the reactant decreases from 0.8M to 0.4M in 15 minutes, i.e. t_1/2 = 15 minutes. Therefore, the concentration of the reactant will fall from 0.1M to 0.025M in two half lives. i.e.    2t_1/2 = 2 × 15 = 30 minutes.

The correct answer is Option D.

From the rate equation rate =k[A][B], we can say that the reaction is first order in A and first order in B. Hence, the overall order of the reaction is 2.
(A)The unit of k must be mol-1s-1
Hence, the statement A is incorrect.
(B) The half life period is not constant. It is inversely proportional to the concentration of reactants. Hence, the statement B is incorrect.
(C) The rate of formation of C is one half the rate of disappearance of A.
 d[C] / dt = −d[A] / 2dt
Hence, the statement C is incorrect.
(D) The value of k is independent of the initial concentration of A and B. Hence, the statement D is correct.

The correct answer is option B
Here, E_f ​> E_b​

 

Unimolecular reaction: Unimolecular reactions involve the decomposition of a single reactant molecule. Since the reaction involves two different reactants, it cannot be an unimolecular reaction.

The correct answer is option A
Let initial concentration be ao​
After concentration decreases by

Using first order kinetic equation,

The correct answer is Option B.
The rate law expression is R=k[CO]2.
When concentration of CO is doubled, the rate law expression becomes ;
R′=k[2CO]2      
=4k[CO]2
=4R.

The correct answer is Option A.

E represents the energy of activation which implies it is the energy below which colliding molecules will not react Arrhenius equation gives the dependence of the rate constant k of a chemical reaction on the absolute temperature T (in Kelvin), where A is the pre-exponential factor (or simply the prefactor), Ea is the activation energy, and R is the Universal gas constant:
By Arrhenius equation, k=Ae^-Ea/RT

The correct answer is option c
NO_(g)+Br_2(g)     ⇌NOBr_2(g)
NOBr2_(g)+NO_(g) 2NOBr_(g)[rate determining step]
Rate of the reaction (r)= K[NOBr₂][NO]
Where [NOBR²]=Kc[NO][Br2]
r=K.K_c.[NO][Br²][NO]
r=K’[NO]²[Br₂].
The order of the reaction with respect to
NO(g)=2.
 

The correct answer is Option D.
 
In presence of catalyst, 
E_(forward) = 80kJ/mol  and, 
E_(reverse) = 100kJ/mol.
 
Therefore, H_(reaction) =E_(reverse)−E_(forward)
=100−80
=20kJ/mol. 

The correct answer is Option A.
For first-order reaction, half-life t1/2 = 
Since half-life does not depend on the concentration of reactants.
 
According to the given data, the order of reaction with respect to B is one, hence, does not change half-life.
 
Similarly, an order of reaction with respect to A is also one since the rate increases twice on doubling the concentration.
Hence, total order = 1 + 1 = 2 

Second order reaction and its unit is Lmol⁻¹s⁻¹.

The correct answer is option A
For the reaction rate of disappearance of A is related to rate of appearance of B by the expression:

The correct answer is Option B.
The half life period t_1/2 = 6.93 min.
The decay constant λ = 0.69/t1/2
                                  =0.693/6.93min
​                  =0.1/min
t = (2.303/λ) log a / a−x
t = 2.303/(0.1/min) log 100/(100-99)
t = 46.06 min
Hence, the time required for 99% completion of the reaction is 46.06 min.
 

The correct answer is Option C

The correct answer is Option B.
 
For every 10 °C rise of temperature, the rate is doubled. Thus, temperature coefficient of the reaction =2
When temperature is increased by 50°, rate becomes = 2^(50/10)
= 2⁵ times
= 32

k = 2.303/40*log(0.1/0.025)

k = 0.693/20

For a First order reaction,

rate = k[A]

rate = 0.693*10^-2/20

The correct option is D.

The correct answer is Option C.

Now 2.303log10 
2.303log102 = 
∴
=53598.6 J 
=53.6 kJmol⁻¹