• Keneitsino Lydia
• March 10, 2026

Master 30 Temperature Effect on Reaction Rate MCQs – Powerful Practice for NEET, JEE & CUET

1. Activation energy from rate constants

Q1. For the reaction of H₂ with I₂, the rate constant is 2.5×10−4 dm3 mol−1 s−12.5 \times 10^{-4}\ \mathrm{dm^3\,mol^{-1}\,s^{-1}}2.5×10−4 dm3mol−1s−1 at 327°C and 1.0 dm3 mol−1 s−11.0\ \mathrm{dm^3\,mol^{-1}\,s^{-1}}1.0 dm3mol−1s−1 at 527°C. The activation energy for the reaction is:

A. 59 kJ mol⁻¹
B. 79 kJ mol⁻¹
C. 89 kJ mol⁻¹
D. 166 kJ mol⁻¹

Answer: D

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2. Temperature Rise Effect

Q2. For many reactions, the rate of reaction approximately doubles when the temperature increases by:

A. 5°C
B. 10°C
C. 15°C
D. 20°C

Answer: B

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3. Gradient of ln⁡k\ln klnk vs 1/RT1/RT1/RT

Q3. If a reaction follows the Arrhenius equation, the plot of ln⁡k\ln klnk versus 1/RT1/RT1/RT gives a straight line with gradient (−y)(-y)(−y). The energy required to activate the reactant is:

A. EaE_aEa​ unit
B. RRR unit
C. yRyRyR unit
D. yyy unit

Answer: D

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4. Wrong statement

Q4. Which of the following is the wrong statement?

A. k=Ak = Ak=A if Ea=0E_a = 0Ea​=0
B. e−Ea/RTe^{-E_a/RT}e−Ea​/RT gives the fraction of molecules activated at a given temperature
C. Plot of ln⁡k\ln klnk versus 1/T1/T1/T is a straight line
D. Presence of catalyst will not alter the value of EaE_aEa​

Answer: D

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5. Zero activation energy

Q5. The activation energy of a reaction is zero. Its rate constant at 280 K is 1.6×10−6 s−11.6 \times 10^{-6}\ \mathrm{s^{-1}}1.6×10−6 s−1. The rate constant at 300 K is:

A. 3.2×10−4 s−13.2 \times 10^{-4}\ \mathrm{s^{-1}}3.2×10−4 s−1
B. 1.6×10−6 s−11.6 \times 10^{-6}\ \mathrm{s^{-1}}1.6×10−6 s−1
C. Zero
D. 1.6×10−4 s−11.6 \times 10^{-4}\ \mathrm{s^{-1}}1.6×10−4 s−1

Answer: B

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6. Another zero activation energy question

Q6. For a reaction, Ea=0E_a = 0Ea​=0, and the rate constant at 200 K is 1.6×10−6 s−11.6 \times 10^{-6}\ \mathrm{s^{-1}}1.6×10−6 s−1. The rate constant at 400 K will be:

A. 1.6×104 s−11.6 \times 10^{4}\ \mathrm{s^{-1}}1.6×104 s−1
B. 1.6×10−6 s−11.6 \times 10^{-6}\ \mathrm{s^{-1}}1.6×10−6 s−1
C. 1.6×10−4 s−11.6 \times 10^{-4}\ \mathrm{s^{-1}}1.6×10−4 s−1
D. 3.2×10−4 s−13.2 \times 10^{-4}\ \mathrm{s^{-1}}3.2×10−4 s−1

Answer: B

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7. Doubling of rate constant

Q7. The rate constant is doubled when temperature increases from 27°C to 37°C. The activation energy is:

A. 34 kJ
B. 54 kJ
C. 50 kJ
D. 100 kJ

Answer: B

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8. Activation energy on heating from 300 K to 400 K

Q8. What is the activation energy for a reaction if its rate constant doubles when temperature is raised from 300 K to 400 K?

A. 68.8 kJ mol⁻¹
B. 6.88 kJ mol⁻¹
C. 34.4 kJ mol⁻¹
D. 3.44 kJ mol⁻¹

Answer: B

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9. Arrhenius Plot

Q9. A plot of In k versus 1/T according to Arrhenius equation gives:

A. Parabola
B. Straight line
C. Hyperbola
D. Circle

Answer: B

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10. Expression for activation energy

Q10. The rate constant of a reaction is 1.5×10−31.5 \times 10^{-3}1.5×10−3 at 25°C and 2.1×10−22.1 \times 10^{-2}2.1×10−2 at 60°C. The correct expression for activation energy is:

A. 35333Rln⁡(2.1×10−21.5×10−2)\frac{35}{333}R\ln\left(\frac{2.1\times10^{-2}}{1.5\times10^{-2}}\right)33335​Rln(1.5×10−22.1×10−2​)
B. 298×33335Rln⁡(211.5)\frac{298\times333}{35}R\ln\left(\frac{21}{1.5}\right)35298×333​Rln(1.521​)
C. 298×33335Rln⁡(2.1)\frac{298\times333}{35}R\ln(2.1)35298×333​Rln(2.1)
D. 298×33335Rln⁡(2.11.5)\frac{298\times333}{35}R\ln\left(\frac{2.1}{1.5}\right)35298×333​Rln(1.52.1​)

Answer: B

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11. Arrhenius plot

Q11. Under normal circumstances, the Arrhenius plot is obtained by plotting:

A. log⁡(1/k)\log(1/k)log(1/k) versus 1/T1/T1/T
B. log⁡k\log klogk versus TTT
C. log⁡k\log klogk versus 1/T1/T1/T
D. log⁡(1/k)\log(1/k)log(1/k) versus TTT

Answer: C

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12. Half-life problem using Arrhenius equation

Q12. For a certain reaction, A=4×1013 s−1A = 4 \times 10^{13}\ \mathrm{s^{-1}}A=4×1013 s−1 and Ea=98.6 kJ mol−1E_a = 98.6\ \mathrm{kJ\,mol^{-1}}Ea​=98.6 kJmol−1. If the reaction is first order, the temperature at which the half-life is 10 minutes is:

A. 325.60 K
B. 311.35 K
C. 300 K
D. 520.05 K

Answer: B

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13. Temperature where two rate constants are equal

Q13. For the gaseous reactions
A→Product, k1=1015e−2000/TA \to \text{Product},\ k_1 = 10^{15}e^{-2000/T}A→Product, k1​=1015e−2000/T
C→D, k2=1014e−1000/TC \to D,\ k_2 = 10^{14}e^{-1000/T}C→D, k2​=1014e−1000/T

The temperature at which k1=k2k_1 = k_2k1​=k2​ is:

A. 2000 K
B. 868.8 K
C. 434.2 K
D. 1000 K

Answer: C

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14. Find EaE_aEa​ and kkk

Q14. For the equation ln⁡k=−2576T+12.1\ln k = -\frac{2576}{T} + 12.1lnk=−T2576​+12.1, the value of EaE_aEa​ and kkk at 27°C are:

A. Ea=21.416 kJE_a = 21.416\ \mathrm{kJ}Ea​=21.416 kJ, k=0.335×102 min−1k = 0.335 \times 10^2\ \mathrm{min^{-1}}k=0.335×102 min−1
B. Ea=11.4 kJE_a = 11.4\ \mathrm{kJ}Ea​=11.4 kJ, k=0.335×107 min−1k = 0.335 \times 10^7\ \mathrm{min^{-1}}k=0.335×107 min−1
C. Ea=21.4 kJE_a = 21.4\ \mathrm{kJ}Ea​=21.4 kJ, k=0.3×107 min−1k = 0.3 \times 10^7\ \mathrm{min^{-1}}k=0.3×107 min−1
D. Ea=21.416 kJE_a = 21.416\ \mathrm{kJ}Ea​=21.416 kJ, k=0.335×102 mink = 0.335 \times 10^2\ \mathrm{min}k=0.335×102 min

Answer: A

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15. Arrhenius equation form

Q15. Which of the following represents the Arrhenius equation?

A. k=AeEa/RTk = Ae^{E_a/RT}k=AeEa​/RT
B. k=AeRT/Eak = Ae^{RT/E_a}k=AeRT/Ea​
C. k=AeEa/RTk = \frac{A}{e^{E_a/RT}}k=eEa​/RTA​
D. None of these

Answer: C

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16. Backward activation energy

Q16. For the reaction A→BA \to BA→B, ΔH=20 kJ mol−1\Delta H = 20\ \mathrm{kJ\,mol^{-1}}ΔH=20 kJmol−1 and activation energy of forward reaction is 85 kJ mol⁻¹. The activation energy of backward reaction is:

A. 105 kJ mol⁻¹
B. 65 kJ mol⁻¹
C. 45 kJ mol⁻¹
D. 75 kJ mol⁻¹

Answer: B

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17. Endothermic reaction and minimum activation energy

Q17. For an endothermic reaction, the minimum value of activation energy for the forward reaction will be:

A. Less than ΔH\Delta HΔH
B. More than ΔH\Delta HΔH
C. Equal to ΔH\Delta HΔH
D. Zero

Answer: B

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18. Correct log⁡k\log klogk vs 1/T1/T1/T plot

Q18. The correct graph for log⁡k\log klogk versus 1/T1/T1/T used to calculate EaE_aEa​ is:

A. Option 1
B. Option 2
C. Option 3
D. Option 4

Answer: B

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19. Intercept of ln⁡K\ln KlnK vs 1/T1/T1/T

Q19. A plot of ln⁡K\ln KlnK against 1/T1/T1/T is expected to be a straight line with intercept on the ordinate equal to:

A. ΔS∘/R\Delta S^\circ/RΔS∘/R
B. ΔH∘/R\Delta H^\circ/RΔH∘/R
C. 2.303R2.303R2.303R
D. RΔS∘R\Delta S^\circRΔS∘

Answer: A

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20. Slope of Arrhenius graph

Q20. The slope of the graph drawn between ln⁡k\ln klnk and 1/T1/T1/T gives:

A. Ea/RE_a/REa​/R
B. −Ea/R-E_a/R−Ea​/R
C. EaE_aEa​
D. −Ea-E_a−Ea​

Answer: B

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21. Backward activation energy from enthalpy and forward EaE_aEa​

Q21. The formation of H₂O₂ in the upper atmosphere follows a mechanism with ΔH=72 kJ mol−1\Delta H = 72\ \mathrm{kJ\,mol^{-1}}ΔH=72 kJmol−1 and Ea=77 kJ mol−1E_a = 77\ \mathrm{kJ\,mol^{-1}}Ea​=77 kJmol−1. The activation energy for the backward reaction is:

A. −149 kJ
B. 149 kJ
C. −5 kJ
D. 5 kJ

Answer: D

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22. Catalyst and temperature

Q22. A hydrogenation reaction is carried out at 500 K. In the presence of a catalyst, the same rate is obtained at 400 K. If the catalyst lowers the activation barrier by 40 kJ mol⁻¹, the activation energy of the uncatalyzed reaction is:

A. 10 kJ mol⁻¹
B. 200 kJ mol⁻¹
C. 300 kJ mol⁻¹
D. 175 kJ mol⁻¹

Answer: B

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23. Effect of catalyst

Q23. Addition of a catalyst during a reaction alters:

A. Enthalpy
B. Activation energy
C. Entropy
D. Internal energy

Answer: B

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24. Arrhenius Equation

Q24. The relationship between rate constant and temperature is given by:

A. Nernst equation
B. Arrhenius equation
C. Gibbs equation
D. Van’t Hoff equation

Answer: B

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25. Unit of activation energy

Q25. The unit of activation energy is:

A. s⁻¹
B. K⁻¹ mol⁻¹
C. s
D. J mol⁻¹

Answer: D

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26. Factor by which catalyst increases rate

Q26. For a reaction at 300 K, the uncatalyzed EaE_aEa​ is 76 kJ mol⁻¹ and catalyzed EaE_aEa​ is 57 kJ mol⁻¹. The factor by which the catalyzed reaction rate increases is:

A. 21
B. 2100
C. 2000
D. 1200

Answer: C

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27. Backward activation energy for endothermic process

Q27. For an endothermic process, forward activation energy is 90 kJ and ΔH=50\Delta H = 50ΔH=50 kJ. The backward activation energy is:

A. 40 kJ
B. 90 kJ
C. 140 kJ
D. 50 kJ

Answer: A

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28. Graph used to determine activation energy

Q28. Activation energy can be determined from the slope of which graph?

A. ln⁡k\ln klnk vs 1/T1/T1/T
B. ln⁡k\ln klnk vs TTT
C. log⁡k\log klogk vs TTT
D. Tln⁡kT\ln kTlnk vs TTT

Answer: A

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29. Wrong statement from energy profile

Q29. For a reversible reaction A⇌BA \rightleftharpoons BA⇌B, which statement is wrong from the energy profile diagram?

A. Activation energy of forward reaction is greater than backward reaction
B. Forward reaction is endothermic
C. Threshold energy is less than activation energy
D. Forward activation energy equals heat of reaction plus backward activation energy

Answer: C

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30. Zero activation energy again

Q30. For a reaction, Ea=0E_a = 0Ea​=0, and k=4.2×105 s−1k = 4.2 \times 10^5\ \mathrm{s^{-1}}k=4.2×105 s−1 at 300 K. The value of kkk at 310 K will be:

A. 4.2×105 s−14.2 \times 10^5\ \mathrm{s^{-1}}4.2×105 s−1
B. 8.4×106 s−18.4 \times 10^6\ \mathrm{s^{-1}}8.4×106 s−1
C. 4.2×107 s−14.2 \times 10^7\ \mathrm{s^{-1}}4.2×107 s−1
D. Unpredictable

Answer: A

Conclusion on Temperature Effect On Reaction Rate MCQs

In conclusion, temperature effect on reaction rate mcqs plays a crucial role in determining the speed of chemical reactions. By practicing Temperature effect on reaction rate mcqs, aspirants can strengthen their understanding of activation energy, Arrhenius equations, and molecular collision theory. Consistent practice with Temperature effect on reaction rate mcqs improves problem-solving skills and prepares aspirants for exams where reaction rate concepts are frequently tested.