Chemical kinetics general

Question 1

What things do you look at when you look at kinetics?

Answer 1

How does it happen
What controls it
How fast does it happen

Question 2

What do you learn from looking at kinetics?

Answer 2

Learn about the precise pathway by which the reaction proceeds

Question 3

How can you influence kinetics?

Answer 3

Need to reduce the barrier
Find the bottleneck (slowest part)
Introduce a catalyst to speed it up

Question 4

When there is a collision, what else do you need to look at?

Answer 4

The stochiometry at the moment of the collision

Question 5

What timescales can chemical reactions occur on?

Answer 5

10⁻¹⁴

10⁹

Question 6

What is molecularity?

Answer 6

The number of molecules involved in the collision

Question 7

What is a unimolecular reaction?

Answer 7

Single molecule is involved in the reaction so there is no collision

Question 8

What is a bimolecular reaction?

Answer 8

Two distinct molecules colliding

Question 9

What are the characteristics of molecularity?

Answer 9

• Theoretical concept
• Can not be zero, fractional, infinite or imaginary
• can not be greater than 3

Question 10

Why can molecularity not be greater than 3?

Answer 10

Steric effect

Cant have loads attached

Question 11

What is the definition of rate?

Answer 11

Chemical reaction that occurs according to a balanced chemical equation using the stochiometries of reactants and products determined by certain laws of chemistry

Question 12

What is the general equation for rate of change in conc?

Answer 12

rate = l Δ[J] l / Δt

Question 13

What is Δ[J]?

Answer 13

change in molar concentration of species J

Question 14

What is the modulus for in the rate equation?

Answer 14

Allows us to distinguish between formation of product and disappearance of reactant

Question 15

What is the unique rate of reaction?

Answer 15

Includes the stochiometric numbers and exactly what species you mean

Question 16

What is the equation for the unique rate of reaction?

Answer 16

v = 1 / vj x Δ[J] / Δt

Question 17

What is the rate law?

Answer 17

Equation which expresses the rate of reaction in terms of the molar concentrations of species in the overall reaction

Question 18

What is the general equation for the rate law?

Answer 18

v = k[A]ᵃ[B]ᵇ

Question 19

What is k?

Answer 19

Rate constant

Question 20

What are [A] and [B]?

Answer 20

Concentrations

Question 21

What are ᵃ and ᵇ?

Answer 21

Molar quanitities

Question 22

What is the rate constant independent of?

Answer 22

The concentrations of the species involved in the reaction

Question 23

What is the rate constant often dependent on?

Answer 23

Temperature

Question 24

What are the usual units for the rate of reaction?

Answer 24

mol dm⁻³ s⁻¹

Question 25

What is the rearranged equation to work out the rate constant?

Answer 25

k = v / A]ᵃ[B]ᵇ