Orders and rate equation

Order

the power to which the conc of a reaction is raised in the rate equation.

(EFFECT CONC HAS ON RATE)

diff species have diff effect on rate.

0 order

NOT AFFECTED

rate is independent of conc of A

[2]°=1

1st order

IF CONC DOUBLES, RATE DOUBLES.

rate is proportional to conc of A.

[2]1=2

[2]2=4

2nd order

IF CONC DOUBLES, RATE QUADRUPLES.

[2]2=4

rate equation

rate=k[A][B]

rate constant calculation

k = rate/[A][B]

methods of monitoring rate

1) colorimeter: amount of light absorbed is proportional to conc of species. e.g iodination turns from brown to orange to colourless as reaction occurs.

2) mass change: if gas produces, mass of reaction mixture will decrease.

3) vol of gas formed: measuring vol of gas formed using a gas syringe.

Intial rate from a graph

RATE AT 0.

like ur ruler up with the first 2 points + draw a tangent.