kinetics how do so stuff

Question 1

how can you tell if a reaction is zero order

Answer 1

graph time x axis and concentration of the right axis, if this is a straight line then the reaction is 0 order

Question 2

how can you tell if a reaction is first order

Answer 2

graph time x axis and ln[conc] y axis - straight line is therefore 1st order

Question 3

how can you tell if a reaction is second order

Answer 3

graph time x axis and 1/c y axis and a straight line means second order

Question 4

how to tell the overall order of a reaction

Answer 4

prepare all 3 graph plots and see which one gives the most linear plot

Question 5

what is the rate law equation for 0 order

Answer 5

rate = k[A]0

Question 6

what is the rate law equation for 1 order

Answer 6

rate = k[A]1

Question 7

what is the rate law equation for 2 order

Answer 7

rate = k[A]2

Question 8

what is the integrated rate laws for a zero order reaction

Answer 8

[A] = [A]0-kt

Question 9

what is the integrated rate law for a first order reaction

Answer 9

[A] = [A]0 e^-kt

Question 10

what is the integrated rate law for a second order reaction

Answer 10

[A] = [A]0/(1+Kt[A]0)

Question 11

how do we calculate the rate constant k

Answer 11

to calculate the rate constant K, calculate the gradient of the graph using the 1st and last point and use the equation = y2-y1/x2-x1

Question 12

what are the units of K for a zero order reaction

Answer 12

Ms-1

Question 13

what are the units of K for a first order reaction

Answer 13

s-1

Question 14

what are the units of K for a second order reaction

Answer 14

M-1s-1

Question 15

how do we calculate half life for a 0 order reaction

Answer 15

t1/2 = [A]0/2k

Question 16

how do we calculate half life for a 1 order reaction

Answer 16

t1/2 = 0.693/k

Question 17

how do we calculate half life for a second order reaction

Answer 17

t1/2 = 1/K[A]0

Question 18

how do we calculate the reaction lifetime

Answer 18

for 1st order reactions only
= 1/K

Question 19

how do we calculate concentration after a given time

Answer 19

use integrated rate law and extrapolate the value of the [A]0 from the intercept on the y axis

Question 20

how do we calculate the activation energy for two points

Answer 20

ln(k1/k2) = EA/R(1/t2-1/t1)
use T in kelvin

Question 21

how do we calculate the pre exponential factor for two points

Answer 21

rearrange the arrhenius equation to give
ln(A) = lnK2 +EA/RT2
solve this for Ln(A) and then e ans for A

Question 22

what are the units of A

Answer 22

1st order = s-1
2nd order = M-1S-1

Question 23

how do you find the activation energy for more than 2 points

Answer 23

plot the graph of lnK vs 1/T
calculate the gradient which will be -EA/R and then times by R to get EA

Question 24

how do we calculate the A for more than 2 point

Answer 24

LnA will be the y intercept of the graph therefore A will be eans

Question 25

how doe we calculate the activation enthalpy

Answer 25

ln(k1t2/k2t1) = delta H/R x (1/t2 -1/t1)