Chemical Kinetics and Nuclear Chemistry
224 Questions
Start JEE Mains Test
2020
Q151
JEE Mains
Numerical
14 Mar 2026
During the nuclear explosion, one of the products is 90Sr with half life of 6.93 years. If 1 $\mu $ g of 90Sr was absorbed in the bones of newly born baby in placed of Ca, how much time, in years, is required to reduce much time, in year, is required to reduce it by 90% if it not lost metabolically.
Correct Answer: 23to23.03
Explanation:
All nuclear decays follow first order kinetics
t = ${1 \over k}\ln {{\left[ {{A_0}} \right]} \over {\left[ A \right]}}$
= ${{\left( {{t_{1/2}}} \right)} \over {0.693}} \times 2.303{\log _{10}}10$
= 10 × 2.303 × 1
= 23.03 years
Shortcut Method :
t90% = ${{10} \over 3} \times {t_{50\% }}$
= ${{10} \over 3} \times 6.93$ = 23.1
t = ${1 \over k}\ln {{\left[ {{A_0}} \right]} \over {\left[ A \right]}}$
= ${{\left( {{t_{1/2}}} \right)} \over {0.693}} \times 2.303{\log _{10}}10$
= 10 × 2.303 × 1
= 23.03 years
Shortcut Method :
t90% = ${{10} \over 3} \times {t_{50\% }}$
= ${{10} \over 3} \times 6.93$ = 23.1
2020
Q152
JEE Mains
MCQ
14 Mar 2026
Consider the following reactions
A $ \to $ P1 ; B $ \to $ P2 ; C $ \to $ P3 ; D $ \to $ P4,
The order of the above reactions are a, b, c, and d, respectively. The following graph is obtained when log[rate] vs. log[conc.] are plotted
Among the following, the correct sequence for the order of the reactions is :
A $ \to $ P1 ; B $ \to $ P2 ; C $ \to $ P3 ; D $ \to $ P4,
The order of the above reactions are a, b, c, and d, respectively. The following graph is obtained when log[rate] vs. log[conc.] are plotted
Among the following, the correct sequence for the order of the reactions is :
A.
d > b > a > c
B.
d > a > b > c
C.
a > b > c > d
D.
c > a > b > d
2020
Q153
JEE Mains
MCQ
14 Mar 2026
The rate constant (k) of a reaction is measured at differenct temperatures (T), and the data are
plotted in the given figure. The activation energy of the reaction in kJ mol–1 is :
(R is gas constant)
(R is gas constant)
A.
R
B.
2R
C.
${1 \over R}$
D.
${1 \over {2R}}$
2020
Q154
JEE Mains
MCQ
14 Mar 2026
A flask contains a mixture of compounds A and
B. Both compounds decompose by first-order
kinetics. The half-lives for A and B are 300 s
and 180 s, respectively. If the concentrations
of A and B are equal initially, the time required
for the concentration of A to be four times that
of B(in s) :
(Use ln 2 = 0.693)
(Use ln 2 = 0.693)
A.
180
B.
120
C.
300
D.
900
2020
Q155
JEE Mains
MCQ
14 Mar 2026
For the reaction
2A + 3B + ${3 \over 2}$C $ \to $ 3P, which statement is correct ?
2A + 3B + ${3 \over 2}$C $ \to $ 3P, which statement is correct ?
A.
${{d{n_A}} \over {dt}} = {{d{n_B}} \over {dt}} = {{d{n_C}} \over {dt}}$
B.
${{d{n_A}} \over {dt}} = {2 \over 3}{{d{n_B}} \over {dt}} = {3 \over 4}{{d{n_C}} \over {dt}}$
C.
${{d{n_A}} \over {dt}} = {3 \over 2}{{d{n_B}} \over {dt}} = {3 \over 4}{{d{n_C}} \over {dt}}$
D.
${{d{n_A}} \over {dt}} = {2 \over 3}{{d{n_B}} \over {dt}} = {4 \over 3}{{d{n_C}} \over {dt}}$
2020
Q156
JEE Mains
MCQ
14 Mar 2026
It is true that :
A.
A first order reaction is always a single step reaction
B.
A zero order reaction is a multistep reaction
C.
A zero order reaction is a single step reaction
D.
A second order reaction is always a multistep reaction
2020
Q157
JEE Mains
MCQ
14 Mar 2026
The results given in the below table were
obtained during kinetic studies of the following
reaction
2A + B $ \to $ C + D
X and Y in the given table are respectively :
2A + B $ \to $ C + D
X and Y in the given table are respectively :
A.
0.3, 0.4
B.
0.4, 0.3
C.
0.4, 0.4
D.
0.3, 0.3
2020
Q158
JEE Mains
MCQ
14 Mar 2026
For the following reactions
$A\buildrel {700K} \over \longrightarrow {\mathop{\rm Product}\nolimits} $
$A\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{catalyst}^{500K}} {\mathop{\rm Product}\nolimits} $
it was found that Ea is decreased by 30 kJ/mol in the presence of catalyst.
If the rate remains unchanged, the activation energy for catalysed reaction is (Assume pre exponential factor is same):
$A\buildrel {700K} \over \longrightarrow {\mathop{\rm Product}\nolimits} $
$A\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{catalyst}^{500K}} {\mathop{\rm Product}\nolimits} $
it was found that Ea is decreased by 30 kJ/mol in the presence of catalyst.
If the rate remains unchanged, the activation energy for catalysed reaction is (Assume pre exponential factor is same):
A.
198 kJ/mol
B.
135 kJ/mol
C.
105 kJ/mol
D.
75 kJ/mol
2020
Q159
JEE Mains
MCQ
14 Mar 2026
Consider the following plots of rate constant
versus ${1 \over T}$ for four different reactions. Which
of the following orders is correct for the
activation energies of these reactions?
A.
Ec > Ea > Ed > Eb
B.
Ea > Ec > Ed > Eb
C.
Eb > Ea > Ed > Ec
D.
Eb > Ed > Ec > Ea
2020
Q160
JEE Mains
MCQ
14 Mar 2026
The rate of a certain biochemical reaction at physiological temperature (T) occurs 106 times faster with
enzyme than without. The change in the activation energy upon adding enzyme is :
A.
+ 6RT
B.
– 6 (2.303)RT
C.
– 6RT
D.
+ 6(2.303)RT
2020
Q161
JEE Mains
MCQ
14 Mar 2026
For the reaction
2H2(g) + 2NO(g) $ \to $ N2(g) + 2H2O(g)
the observed rate expression is, rate = Kf[NO]2[H2]. The rate expression for the reverse reaction is :
2H2(g) + 2NO(g) $ \to $ N2(g) + 2H2O(g)
the observed rate expression is, rate = Kf[NO]2[H2]. The rate expression for the reverse reaction is :
A.
Kb[N2][H2O]
B.
Kb[N2][H2O]2/[H2]
C.
Kb[N2][H2O]2/[NO]
D.
Kb[N2][H2O]2
2019
Q162
JEE Mains
MCQ
14 Mar 2026
NO2 required for a reaction is produced by the decomposition of N2O5 in CCl4 as per the equation,
2N2O5(g) $ \to $ 4NO2(g) + O2(g).
The initial concentration of N2O5 is 3.00 mol L–1 and it is 2.75 mol L–1 after 30 minutes. The rate of formation of NO2 is :
2N2O5(g) $ \to $ 4NO2(g) + O2(g).
The initial concentration of N2O5 is 3.00 mol L–1 and it is 2.75 mol L–1 after 30 minutes. The rate of formation of NO2 is :
A.
2.083 × 10–3
mol L–1
min–1
B.
8.333 × 10–3
mol L–1
min–1
C.
4.167 × 10–3
mol L–1
min–1
D.
1.667 × 10–2
mol L–1
min–1
2019
Q163
JEE Mains
MCQ
14 Mar 2026
In the following reaction; xA $ \to $ yB
${\log _{10}}\left[ { - {{d\left[ A \right]} \over {dt}}} \right] = {\log _{10}}\left[ {{{d\left[ B \right]} \over {dt}}} \right] + 0.3010$
'A' and 'B' respectively can be :
${\log _{10}}\left[ { - {{d\left[ A \right]} \over {dt}}} \right] = {\log _{10}}\left[ {{{d\left[ B \right]} \over {dt}}} \right] + 0.3010$
'A' and 'B' respectively can be :
A.
n-Butane and Iso-butane
B.
C2H4 and C4H8
C.
C2H4 and C6H6
D.
N2O4 and NO2
2019
Q164
JEE Mains
MCQ
14 Mar 2026
For the reaction of H2 with I2, the rate constant is 2.5 × 10–4 dm3
mol–1s–1
at 327°C and 1.0 dm3
mol–1
at
527°C. The activation energy for the reaction, in kJ mole–1
is : (R = 8.314 JK–1
mol–1
)
A.
59
B.
166
C.
72
D.
150
2019
Q165
JEE Mains
MCQ
14 Mar 2026
A bacterial infection in an internal wound grows as N'(t) = N0 exp(t), where the time t is in hours. A does of antibiotic, taken orally, needs 1 hour to reach the wound. Once it reaches there, the bacterial population goes down as ${{dN} \over {dt}} = - 5{N^2}$.
What will be the plot of ${{{N_0}} \over N}$
vs. t after 1 hour?
A.
B.
C.
D.
2019
Q166
JEE Mains
MCQ
14 Mar 2026
Consider the given plot of enthalpy of the
following reaction between A and B.
A+ B $ \to $ C + D
Identify the incorrect statement.
A+ B $ \to $ C + D
Identify the incorrect statement.
A.
Formation of A and B from C has highest
enthalpy of activation.
B.
D is kinetically stable product.
C.
C is the thermodynamically stable product
D.
Activation enthalpy to form C is 5kJ mol–1
less than that to form D.
2019
Q167
JEE Mains
MCQ
14 Mar 2026
The given plots represent the variation of the
concentration of a reactant R with time for two
different reactions (i) and (ii). The respective
orders of the reactions are :
A.
0,1
B.
1,0
C.
0,2
D.
1,1
2019
Q168
JEE Mains
MCQ
14 Mar 2026
For a reaction scheme $A\buildrel {{k_1}} \over
\longrightarrow B\buildrel {{k_2}} \over
\longrightarrow C$,
if the rate of formation of B is set to be zero then the concentration of B is given by :
if the rate of formation of B is set to be zero then the concentration of B is given by :
A.
${k_1}{k_2}[A]$
B.
$\left( {{{{k_1}} \over {{k_2}}}} \right)[A]$
C.
$({k_1} + {k_2})[A]$
D.
$({k_1} - {k_2})[A]$
2019
Q169
JEE Mains
MCQ
14 Mar 2026
For the reaction 2A + B $ \to $ C, the values of initial rate at diffrent reactant concentrations are
given in the table below. The rate law for the reaction is :
| [A] (mol L-1) | [B] (mol L-1) | Initial Rate (mol L-1s-1) |
|---|---|---|
| 0.05 | 0.05 | 0.045 |
| 0.10 | 0.05 | 0.090 |
| 0.20 | 0.10 | 0.72 |
A.
Rate = k[A][B]2
B.
Rate = k[A]2[B]2
C.
Rate = k[A]2[B]
D.
Rate = k[A][B]
2019
Q170
JEE Mains
MCQ
14 Mar 2026
For a reaction consider the plot of $\ell $n k versus 1/T given in the figure. If the rate constant of this reaction at 400 K is 10–5 s–1, then the rate constant at 500 K is –
A.
10$-$4 s$-$1
B.
4 $ \times $ 10$-$4 s$-$1
C.
10$-$6 s$-$1
D.
2 $ \times $ 10$-$4 s$-$1
2019
Q171
JEE Mains
MCQ
14 Mar 2026
Decomposition of X exhibits a rate constant of 0.05 $\mu $g/year. How many year are required for the decomposition of 5$\mu $g of X into 2.5 $\mu $g?
A.
50
B.
20
C.
25
D.
40
2019
Q172
JEE Mains
MCQ
14 Mar 2026
The reaction 2X $ \to $ B is a zeroth order reaction. If the initial concentration of X is 0.2 M, the half-life is 6 h. When the initial concentration of X is 0.5 M, the time required to reach its final concentration of 0.2 M will
be:
A.
18.0 h
B.
9.0 h
C.
7.2 h
D.
12.0 h
2019
Q173
JEE Mains
MCQ
14 Mar 2026
If a reaction follows the Arrhenius equation, the plot ln k vs ${1 \over {\left( {RT} \right)}}$ gives straight line with a gradient ($-$ y) unit.
The energy required to active the reactant is :
The energy required to active the reactant is :
A.
y unit
B.
y/R unit
C.
yR unit
D.
$-$y unit
2019
Q174
JEE Mains
MCQ
14 Mar 2026
For an elementary chemical reaction,
the expression for ${{d\left[ A \right]} \over {dt}}$ is
the expression for ${{d\left[ A \right]} \over {dt}}$ is
A.
2K1[A2] – K –1 [A]2
B.
K1[A2] – K –1 [A]2
C.
K1[A2] + K –1 [A]2
D.
2K1[A2] – 2K –1 [A]2
2019
Q175
JEE Mains
MCQ
14 Mar 2026
Consider the given plots for a reaction obeying Arrhenius equation (0oC < T < 300oC) : (K and Ea are rate constant and activation energy, respectively)
Choose the correct option :
Choose the correct option :
A.
I is right but II is wrong
B.
Both I and II are correct
C.
Both I and II are wrong
D.
I is wrong but II is right
2019
Q176
JEE Mains
MCQ
14 Mar 2026
For the reaction, 2A + B $ \to $ products, when the concentrations of A and B both were doubled, the rate of the reaction increased from 0.3 mol L$-$1s$-$1 to 2.4 mol L$-$1s$-$1. When the concentration of A alone is doubled, the rate increased from 0.3 mol L$-$1s$-$1 to 0.6 mol L$-$1s$-$1.
A.
Total order of the reaction is 4
B.
Order of the reaction with respect to B is 2
C.
Order of the reaction with respect to B is 1
D.
Order of the reaction with respect to A is 2
2019
Q177
JEE Mains
MCQ
14 Mar 2026
The following results were obtained during kinetic studies of the reaction ;
2A + B $ \to $ Products
The time (in minutes) required to consume half of A is :
2A + B $ \to $ Products
| Experiment | [A] (in mol L$-$1) | [b] (in mol L$-$1) | Initial Rate of reaction (In mol L$-$1 min$-$1) |
|---|---|---|---|
| I | 0.10 | 0.20 | 6.93 G 10$-$3 |
| II | 0.10 | 0.25 | 6.93 G 10$-$3 |
| III | 0.20 | 0.30 | 1.386 G 10$-$2 |
The time (in minutes) required to consume half of A is :
A.
5
B.
10
C.
1
D.
100
2018
Q178
JEE Mains
MCQ
14 Mar 2026
If 50% of a reaction occurs in 100 second and 75% of the reaction occurs in 200 secod, the order of this reaction is :
A.
Zero
B.
1
C.
2
D.
3
2018
Q179
JEE Mains
MCQ
14 Mar 2026
At 518oC the rate of decomposition of a sample of gaseous acetaldehyde initially at a pressure of 363 Torr,
was 1.00 Torr s–1 when 5% had reacted and 0.5 Torr s–1 when 33% had reacted. The order of the reaction is
A.
0
B.
2
C.
3
D.
1
2018
Q180
JEE Mains
MCQ
14 Mar 2026
For a first order reaction, A $ \to $ P, t1/2 (half-life) is 10 days The time required for ${1 \over 4}$th conversion of A (in days) is : (ln 2 = 0.693, ln 3 = 1.1)
A.
5
B.
3.2
C.
4.1
D.
2.5
2018
Q181
JEE Mains
MCQ
14 Mar 2026
N2O5 decomposes to NO2 and O2 and follows first order kinetics. After 50 minutes, the pressure inside the vessel increases from 50 mmHg to 87.5 mmHg. The pressure of the gaseous mixture after 100 minute at constant temperature will be :
A.
175.0 mmHg
B.
116.25 mmHg
C.
136.25 mmHg
D.
106.25 mmHg
2017
Q182
JEE Mains
MCQ
14 Mar 2026
The rate of a reaction quadruples when the temperature changes from 300 to 310 K. The activation energy of this reaction is :
(Assume activation energy and preexponential factor are independent of temperature; ln 2 = 0.693; R = 8.314 J mol−1 K−1)
(Assume activation energy and preexponential factor are independent of temperature; ln 2 = 0.693; R = 8.314 J mol−1 K−1)
A.
107.2 kJ mol$-$1
B.
53.6 kJ mol$-$1
C.
26.8 kJ mol$-$1
D.
214.4 kJ mol$-$1
2017
Q183
JEE Mains
MCQ
14 Mar 2026
The rate of a reaction A doubles on increasing the temperature from 300 to 310 K. By how much, the temperature of reaction B should be Increased from 300 K so that rate doubles if activation energy of the reaction B is twice to that of reaction A.
A.
9.84 K
B.
4.92 K
C.
2.45 K
D.
19.67 K
2017
Q184
JEE Mains
MCQ
14 Mar 2026
Two reactions R1 and R2 have identical pre-exponential factors. Activation energy of R1 exceeds that of R2 by 10 kJ mol–1. If k1 and k2 are rate constants for reactions R1 and R2 respectively at 300 K, then ln(k2/k1) is equal to :
(R = 8.314 J mol–1 K–1)
(R = 8.314 J mol–1 K–1)
A.
12
B.
6
C.
4
D.
8
2016
Q185
JEE Mains
MCQ
14 Mar 2026
The rate law for the reaction below is given by the expression k [A] [B]
A + B $ \to $ Product
If the concentration of B is increased from 0.1 to 0.3 mole, keeping the value of A at 0.1 mole, the rate constant will be :
A + B $ \to $ Product
If the concentration of B is increased from 0.1 to 0.3 mole, keeping the value of A at 0.1 mole, the rate constant will be :
A.
k
B.
k/3
C.
3k
D.
9k
2016
Q186
JEE Mains
MCQ
14 Mar 2026
The reaction of ozone with oxygen atoms in the presence of chlorine atoms can occur
by a two step process shown below :
O3(g) + Cl${^ \bullet }$ (g) $ \to $ O2(g) + ClO${^ \bullet }$ (g) . . . . . .(i)
ki = 5.2 × 109 L mol−1 s−1
ClO${^ \bullet }$(g) + O${^ \bullet }$(g) $ \to $ O2(g) + Cl${^ \bullet }$ (g) . . . . . . (ii)
kii = 2.6 × 1010 L mol−1 s−1
The closest rate constant for the overall reaction O3(g) + O${^ \bullet }$ (g) $ \to $ 2 O2(g) is :
O3(g) + Cl${^ \bullet }$ (g) $ \to $ O2(g) + ClO${^ \bullet }$ (g) . . . . . .(i)
ki = 5.2 × 109 L mol−1 s−1
ClO${^ \bullet }$(g) + O${^ \bullet }$(g) $ \to $ O2(g) + Cl${^ \bullet }$ (g) . . . . . . (ii)
kii = 2.6 × 1010 L mol−1 s−1
The closest rate constant for the overall reaction O3(g) + O${^ \bullet }$ (g) $ \to $ 2 O2(g) is :
A.
5.2 × 109 L mol−1 s−1
B.
2.6 × 1010 L mol−1 s−1
C.
3.1 × 1010 L mol−1 s−1
D.
1.4 × 1020 L mol−1 s−1
2016
Q187
JEE Mains
MCQ
14 Mar 2026
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.
6.93 $\times$ 10-4 mol min-1
B.
6.96 $\times$ 10-2 mol min-1
C.
1.34 $\times$ 10-2 mol min-1
D.
2.66 L min–1 at STP
2015
Q188
JEE Mains
MCQ
14 Mar 2026
Higher order (>3) reactions are rare due to
A.
increase in entropy and activation energy as more molecules are involved
B.
shifting of equilibrium towards reactants due to elastic collisions
C.
loss of active species on collision
D.
low probability of simultaneous collision of all the reacting species
2014
Q189
JEE Mains
MCQ
14 Mar 2026
For the non – stoichiometre reaction 2A + B $\to$ C + D, the following kinetic data were obtained in three
separate experiments, all at 298 K.
The rate law for the formation of C is:
| Initial Concentration (A) | Initial Concentration (B) | Initial rate of formation of C (mol L-1 s-1) |
|---|---|---|
| 0.1 M | 0.1 M | 1.2 x 10-3 |
| 0.1 M | 0.2 M | 1.2 x 10-3 |
| 0.2 M | 0.1 M | 2.4 x 10-3 |
A.
${{dc} \over {dt}} = k[A]{[B]^2}$
B.
${{dc} \over {dt}} = k[A]$
C.
${{dc} \over {dt}} = k[A]{[B]}$
D.
${{dc} \over {dt}} = k[A^2]{[B]}$
2013
Q190
JEE Mains
MCQ
14 Mar 2026
The rate of a reaction doubles when its temperature changes from 300K to 310K. Activation energy of such
a reaction will be:(R = 8.314 JK–1 mol–1 and log 2 = 0.301)
A.
48.6 kJ mol–1
B.
58.5 kJ mol–1
C.
60.5 kJ mol–1
D.
53.6 kJ mol–1
2012
Q191
JEE Mains
MCQ
14 Mar 2026
For a first order reaction, (A) $\to$ products, the concentration of A changes from 0.1 M to 0.025 M in 40
minutes. The rate of reaction when the concentration of A is 0.01 M is :
A.
1.73 x 10–5 M/ min
B.
3.47 x 10–4 M/min
C.
3.47 x 10–5 M/min
D.
1.73 x 10–4 M/min
2011
Q192
JEE Mains
MCQ
14 Mar 2026
The rate of a chemical reaction doubles for every 10oC rise of temperature. If the temperature is raised
by 50oC , the rate of the reaction increases by about :
A.
24 times
B.
32 times
C.
64 times
D.
10 times
2010
Q193
JEE Mains
MCQ
14 Mar 2026
The time for half life period of a certain reaction A $\to$ products is 1 hour. When the initial
concentration of the reactant ‘A’, is 2.0 mol L–1, how much time does it take for its concentration to
come from 0.50 to 0.25 mol L–1 if it is a zero order reaction ?
A.
4 h
B.
0.5 h
C.
0.25 h
D.
1 h
2010
Q194
JEE Mains
MCQ
14 Mar 2026
Consider the reaction :
Cl2(aq) + H2S(aq) → S(s) + 2H+ (aq) + 2Cl– (aq)
The rate equation for this reaction is rate = k [Cl2] [H2S]
Which of these mechanisms is/are consistent with this rate equation?
(A) Cl2 + H2S $\to$ H+ + Cl– + Cl+ + HS– (slow)
Cl+ + HS– $\to$ H+ + Cl– + S (fast)
(B) H2S $ \Leftrightarrow $ H+ + HS– (fast equilibrium)
Cl2 + HS– $\to$ 2Cl– + H+ + S (slow)
A.
B only
B.
Both A and B
C.
Neither A nor B
D.
A only
2009
Q195
JEE Mains
MCQ
14 Mar 2026
The half life period of a first order chemical reaction is 6.93 minutes. The time required for the
completion of 99% of the chemical reaction will be (log 2=0.301) :
A.
230.3 minutes
B.
23.03 minutes
C.
46.06 minutes
D.
460.6 minutes
2008
Q196
JEE Mains
MCQ
14 Mar 2026
For a reaction ${1 \over 2}A \to 2B$ rate of disappearance of ‘A’ is related to the rate of appearance of ‘B’ by the
expression
A.
$ - {{d[A]} \over {dt}}$ = ${1 \over 2}{{d[B]} \over {dt}}$
B.
$ - {{d[A]} \over {dt}}$ = ${1 \over 4}{{d[B]} \over {dt}}$
C.
$ - {{d[A]} \over {dt}}$ = ${{d[B]} \over {dt}}$
D.
$ - {{d[A]} \over {dt}}$ = $4{{d[B]} \over {dt}}$
2007
Q197
JEE Mains
MCQ
14 Mar 2026
Consider the reaction, 2A + B $\to$ products. When concentration of B alone was doubled, the half-life did not change. When the concentration of A
alone was doubled, the rate increased by two times. The unit of rate constant for this reaction is
A.
L mol-1 s-1
B.
no unit
C.
mol L-1 s-1
D.
s-1
2007
Q198
JEE Mains
MCQ
14 Mar 2026
A radioactive element gets spilled over the floor of a room. Its half-life period is 30 days. If the initial
activity is ten times the permissible value, after how many days will it be safe to enter the room?
A.
1000 days
B.
300 days
C.
10 days
D.
100 days
2007
Q199
JEE Mains
MCQ
14 Mar 2026
Which of the following nuclear reactions will generate an isotope?
A.
neutron particle emission
B.
positron emission
C.
$\alpha$-particle emission
D.
$\beta$-particle emission
2007
Q200
JEE Mains
MCQ
14 Mar 2026
The energies of activation for forward and reverse reactions for A2 + B2 $\leftrightharpoons$ 2AB are 180 kJ mol−1
and 200 kJ mol−1 respectively. The presence of catalyst lowers the activation energy of both (forward and reverse) reactions by 100 kJ mol−1. The enthalpy change of the reaction ( A2 + B2 $\to$ 2AB) in the presence of catalyst will be (in kJ mol−1)
A.
300
B.
120
C.
200
D.
20