Activation Energy and Arrhenius Equation
Chemistry ⇒ Chemical Kinetics and Equilibrium
Activation Energy and Arrhenius Equation starts at 11 and continues till grade 12.
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A reaction has an activation energy of 50 kJ mol-1. If the temperature is increased from 300 K to 320 K, will the rate constant increase or decrease?
A reaction has an activation energy of 75 kJ mol-1. If the temperature increases, what happens to the rate constant?
Describe how you would determine the activation energy of a reaction experimentally.
Describe the difference between activation energy and enthalpy change of a reaction.
A plot of ln k versus 1/T for a reaction gives a straight line with a slope of -6000 K. Calculate the activation energy (Ea). (R = 8.314 J mol-1 K-1)
A reaction has a pre-exponential factor (A) of 1.0 × 1013 s-1 and an activation energy of 60 kJ mol-1. Calculate the rate constant at 300 K. (R = 8.314 J mol-1 K-1)
A reaction has a rate constant of 1.2 × 10-4 s-1 at 350 K and 2.4 × 10-4 s-1 at 360 K. Calculate the activation energy (Ea). (R = 8.314 J mol-1 K-1)
The rate constant for a reaction at 298 K is 2.5 × 10-3 s-1. At 308 K, it is 5.0 × 10-3 s-1. Calculate the activation energy (Ea). (R = 8.314 J mol-1 K-1)
If the activation energy of a reaction is high, the reaction rate will be:
(1) Fast
(2) Slow
(3) Unchanged
(4) Cannot be determined
Which of the following best describes the effect of a catalyst on a reaction profile diagram?
(1) Lowers the energy of reactants
(2) Lowers the activation energy barrier
(3) Increases the energy of products
(4) Increases the activation energy barrier
Which of the following best explains why not all collisions between reactant molecules lead to a reaction?
(1) All collisions have enough energy
(2) Only collisions with energy greater than or equal to the activation energy and proper orientation result in reaction
(3) Collisions are always elastic
(4) All collisions are ineffective
Which of the following factors does NOT affect the activation energy of a reaction?
(1) Presence of a catalyst
(2) Temperature
(3) Nature of reactants
(4) Reaction mechanism
Fill in the blank: According to the Arrhenius equation, as activation energy increases, the rate constant __________.
Fill in the blank: The activation energy is the energy difference between the reactants and the __________ state.
Fill in the blank: The activation energy is usually expressed in units of __________.
Fill in the blank: The Arrhenius equation shows that the rate constant increases __________ with temperature.
True or False: A catalyst increases the activation energy of a reaction.
True or False: All reactions with low activation energy are fast at room temperature.
True or False: The activation energy is always positive.
True or False: The Arrhenius equation applies only to gas-phase reactions.
