TOPIC 16 - Kinetics II

Question 1

What is the rate of reaction?

Answer 1

Question 2

What are the different ways to measure the rate of reaction experimentally?

Answer 2

• Measuring change in electrical conductivity (if there is a change in the number of ions)
• Amount of mass lost (for when a gas is produced)
• Volume of gas produced with a gas syringe (whena. gas is produced)
• Change in pH (when there’s a change in H+)
• Titration (taking aliquots(small samples) )
• Colourimeter (Use calibration curve to know which %absorbance corresponds to a specific concentration)

Question 3

How do you measure the rate of reaction with titrations?

Answer 3

Small samples (aliquots) are taken from the reaction mixture at specific time interval.

Before titration aliquotes are quenched to try and stop the reaction. This is done by dilution, cooling it down and even using a quenching agent.

Then titrations are carried out to find the concentration at certain times.

Question 4

What is the rate equation?

Answer 4

Question 5

Wha is the order of reaction?

Answer 5

Question 6

What does it means if a reactant is zero order with respect to a reaction?

Answer 6

Question 7

What does it means if a reactant is first order with respect to a reaction?

Answer 7

Question 8

What does it means if a reactant is second order with respect to a reaction?

Answer 8

Question 9

How is the order of a reactant determined?

Answer 9

From experimental data only.

Question 10

Does K depend on temperature?

Answer 10

Yes. The higher the temperature, the bigger K is.

Question 11

Answer 11

Question 12

Answer 12

Question 13

How is the rate equation determined experimentally for a reaction?

Answer 13

Question 14

Answer 14

Question 15

Answer 15

Question 16

What 3 assumptions are made when finding the initial rate of a clock reaction?

Answer 16

Question 17

How does the iodine clock reaction work?

Answer 17

Question 18

What are the concentration-time and rate-conc graph for a 0 order reactant?

Answer 18

Question 19

What are the concentration-time and rate-conc graph for a 1 order reactant?

Answer 19

Question 20

What are the concentration-time and rate-conc graph for a 2 order reactant?

Answer 20

Question 21

What is the half life of a reactant?

Answer 21

The time it takes for half of the reactant to be used up.

Question 22

What happens to the half life of a zero order reactant?

Answer 22

Question 23

What happens to the half life of a first order reactant?

Answer 23

Question 24

What happens to the half life of a second order reactant?

Answer 24

Question 25

What is the rate determining step?

Answer 25

The slowest step in a multi-step reaction. The rate of the whole reaction depends on the rate of the rate determining step.

Question 26

Could substances that aren’t in the rate equation, be in the rate determining step?

Answer 26

No. All the substances in the rate determining step will be in the rate equation.

Question 27

Can catalysts appear in the rate equation?

Answer 27

Yes.

Question 28

Answer 28

Question 29

Answer 29

Question 30

Which mechanism doest this reaction follow?

Answer 30

Question 31

What are the steps for this reaction?

Answer 31

Question 32

What is the rate equation for the SN2 mechanism?

Answer 32

Question 33

What is the SN2 mechanism for this reaction?

Answer 33

Question 34

What is the rate equation for the SN1 mechanism?

Answer 34

Question 35

What is the SN2 mechanism for this reaction?

Answer 35

Question 36

What is the Arrhenius equation?

Answer 36

Question 37

Answer 37

Question 38

In a graph of lnK (y-axis) against 1/T (x-axis). What doe the gradeint represent?

Answer 38

-Ea/R