Arrhenius equation and activation energy

27 questions on Arrhenius equation and activation energy from the Chemical Kinetics chapter: 5 NEET level, 11 JEE Main, 11 JEE Advanced. Each one opens with its answer and solution.

• In the Arrhenius equation k = A e^-E_a/RT, the pre-exponential factor A has the same units as NEET level
• A catalyst increases the rate of a reaction by NEET level
• A plot of ln k against 1/T for a reaction obeying the Arrhenius equation is a straight line whose slope equals NEET level
• In the expression k = A e^-E_a/RT, the factor e^-E_a/RT represents NEET level
• The rate of most reactions increases markedly with temperature mainly because NEET level
• A reaction has E_a=60 kJ mol^-1 and k=2.0x10^-3 s^-1 at 300 K. Using R=8.314 J mol^-1K^-1, the rate constant at 320 K, in s^-1, is JEE Main level
• The rate constant of a reaction is 3.0x10^-4 s^-1 at 400 K and 6.0x10^-3 s^-1 at 440 K. With R=8.314 J mol^-1K^-1 and ln 20=2.996, the activation energy in kJ m... JEE Main level
• A plot of ln k (k in s^-1) against 1/T (T in K) for a reaction is a straight line of slope -6000 K and intercept 20. Taking R=8.314 J mol^-1K^-1 and ln 10 = 2.3... JEE Main level
• For an endothermic reaction with Delta H=+30 kJ mol^-1 the forward activation energy is 80 kJ/mol. A catalyst lowers the forward activation energy by 20 kJ/mol.... JEE Main level
• A first-order reaction has k=1.5x10^-3 s^-1 at 350 K and E_a=50 kJ mol^-1. With R=8.314 J mol^-1K^-1, the pre-exponential factor in s^-1 is JEE Main level
• A reaction has E_a=55 kJ mol^-1. At what temperature (in K, one decimal place) will its rate constant be double the value at 300 K? Use R=8.314 J mol^-1K^-1 and... JEE Main level
• For a reaction with E_a=75 kJ mol^-1, calculate the ratio k_310/k_300 to two decimal places. Use R=8.314 J mol^-1K^-1. JEE Main level
• At 300 K, the fraction of molecular collisions with energy at least E_a=39 kJ mol^-1 is xx10^-7. Find x to two decimal places. Use R=8.314 J mol^-1K^-1. JEE Main level
• Which statements about the Arrhenius equation k=Ae^-E_a/RT are correct (treat A and E_a as temperature independent)? JEE Main level
• Two reactions have the same pre-exponential factor; their activation energies are E_1=40 and E_2=80 kJ mol^-1. Take R=8.314 J mol^-1K^-1. Which statements are c... JEE Main level
• A reaction has forward activation energy 100 kJ/mol and reverse activation energy 60 kJ/mol. Which statements are correct? JEE Main level
• A first-order reaction has a half-life of 40 min at 300 K and E_a=50 kJ mol^-1 (R=8.314 J mol^-1K^-1). The time (in min) for 87.5% completion at 320 K is JEE Advanced level
• A first-order reaction is 20% complete in 30 min at 300 K and 20% complete in 5.0 min at 330 K. With R=8.314 J mol^-1K^-1 and ln6=1.792, the activation energy i... JEE Advanced level
• The rate constant of a reaction at three temperatures is tabulated as log_10k: -0.45 at 300 K, 1.05 at 350 K and 2.17 at 400 K (k in s^-1). Using the end points... JEE Advanced level
• For the reversible elementary reaction A <=> B the activation energies are E_f=90 and E_r=60 kJ mol^-1 (both Arrhenius). The ratio K_320/K_300 of the equilibriu... JEE Advanced level
• The rate of a reaction triples when the temperature is raised from 300 K to 310 K. Assuming the Arrhenius equation holds with constant E_a and A, the ratio k_32... JEE Advanced level
• For a second-order reaction 2A -> products with [A]_0=0.50 M in both runs, the half-life is 100 s at 300 K and 20 s at 320 K. Using R=8.314 J mol^-1K^-1 and ln5... JEE Advanced level
• A first-order reaction has k=4.0x10^-5 s^-1 at 300 K and 1.6x10^-3 s^-1 at 350 K. Using R=8.314 J mol^-1K^-1, ln 40=3.689 and ln10=2.303, calculate log_10(A/s^-... JEE Advanced level
• A catalyst lowers E_a from 100 to 80 kJ/mol but also lowers the pre-exponential factor by a factor of 50 (the catalysed reaction has A_cat=A/50). Using R=8.314 ... JEE Advanced level
• Reaction 1 has E_a=40 kJ mol^-1 and A=10^10 s^-1; reaction 2 has E_a=80 kJ mol^-1 and A=10^15 s^-1. Use R=8.314 J mol^-1K^-1 and ln10^5=11.51. Which statements ... JEE Advanced level
• A reaction obeys the Arrhenius equation with E_a=50 kJ mol^-1 (R=8.314 J mol^-1K^-1). Which statements are correct? JEE Advanced level
• A plot of ln k against 1/T is linear with slope -5000 K and intercept 18 (k in s^-1). Use R=8.314 J mol^-1K^-1, e^18=6.57x10^7, e^8=2981. Which statements are c... JEE Advanced level