40S Unit 2: Chemical Kinetics II

Question 1

what makes the half life for first order reactions special

Answer 1

they are independent of [A]

Question 2

what is the first point of the collision theory

Answer 2

a chemical system consists of particles that are in constant random motion at various speeds. the average kinetic energy of the particle is proportional to the temperature. the distribution of kinetic energies is shown on a Maxwell Boltzman distribution curve

Question 3

what is the second point of the collision theory

Answer 3

a chemical reaction must involve collisions of particles with each other or the walls of the container

Question 4

what is the 3rd point of the collision theory

Answer 4

an effective collision is one that has sufficient energy, equal to or greater than the activation energy, and correct orientation of the colliding particles

Question 5

what is the fourth point of the collision theory

Answer 5

ineffective collisions involve particles that rebound from the collision

Question 6

what is the fifth point of the collision theory

Answer 6

the rate of a given reaction depends on the frequency of collisions and the fraction of those collisions that are effective

Question 7

what is the half life equation for zero order reactions

Answer 7

[A]initial / 2k

Question 8

what is the half life equation for first order reactions

Answer 8

ln(1/2) / -k

Question 9

what is the half life equation for second order reactions

Answer 9

1 / k[A]initial

Question 10

what are the 3 steps for creating a legitimate reaction mechanism

Answer 10

1. each elementary step must only involve 3 or less particles
2. the elementary steps must sum to the total chemical reaction
3. the rate determining step corresponds to the rate law