Orders Of Reaction

Question 1

Order of reaction with respect to a particular reactant

Answer 1

Shows how that reactants concentration will effect the rate of reaction

Question 2

All orders of reaction

Answer 2

0 order
1 order
2 order

Question 3

How can you find the order of reaction of a certain reactant?

Answer 3

Must be from experiments: cannot tell just by looking at it
Plot a concentration time graph for this reactant
Calculate rate at multiple concentrations
Plot a rate-concentration graph

Question 4

0 order

Answer 4

If the concentration of this reactant changes, the rate will stay the same
This reactant has no effect on the rate if you increase it in concentration

Question 5

Concentration-time graph for a 0 order reaction

Answer 5

Straight diagonal line down
Showing no change in gradient: thus the rate remains constant despite the concentration of this reactant on your axis changing

Question 6

Rate-concentration graph for a 0 order reaction

Answer 6

A straight horizontal line across
Showing how the rate will remain constant (on the y axis) despite the change in concentration of this reactant (on the x axis)

Question 7

1 order

Answer 7

If the concentration of this reactant changes, the rate of reaction will change in an equal amount (eg both will double)
The rate of reaction is proportional to the concentration of this reactant

Question 8

1 order of reaction on a concentration time graph

Answer 8

A downwards curve
So if you find rates of reaction at 2 concentrations: the change between these concentrations is equal to change in the rate of reaction = PROPORTIONAL CHANGE

Question 9

1 order of reaction on a rate-concentration graph

Answer 9

A straight line through the origin
To show the proportional change, rate increases proportionally to concentration

Question 10

2 order

Answer 10

The rate of reaction is proportional to the change in concentration squared
(Eg rate increases by x4 if concentration increases by x2)
Change in concentration has squared proportional change on rate

Question 11

Concentration-time graph for a 2 order reactant

Answer 11

Tighter and steeper curve downwards which flattens
To show how calculating finding the rate at 2 concentrations, the change in rate will be squared to the change in the concentration

Question 12

Rate concentration graph for a 2 order reactant

Answer 12

Curve from the origin upwards to show how when concentration increases the rate increases proportional to that change but squared

Question 13

Overall order of reaction

Answer 13

Add together the orders of all reactants
This value may be over 2.

Question 14

Overall order of reaction

Answer 14

Add together the orders of all reactants
This value may be over 2.

Question 15

Why is knowing the order of reaction for reactants important in industry?

Answer 15

So we know which reactant we should change the concentration by to increase the rate of reaction

Question 16

Orders of reaction in the rate equation

Answer 16

The indices of each concentration of reactant is that reactants order of reaction

Question 17

When making a rate-conc graph

Answer 17

The concentration of that reactant must be varied whilst the concentrations of the other reactants should be kept constant

Question 18

What does the number of moles of reactants in the rate determining step show?

Answer 18

The orders of those reactants eg 2NO means NO is 2nd order