lecture 2 - chemical kinetics

Question 1

how do we measure rate of a reaction

Answer 1

measure the conc at a function of time

Question 2

what is the rate constant dependent on

Answer 2

temperature

Question 3

what must be plotted for a first order reaction to give a straight line

Answer 3

ln([a]) against t

gradient = -k
intercept =ln [a0]

Question 4

what must be plotted for a 2nd order reaction to give a straight line

Answer 4

1/[a] against t

gradient = k
intercept = 1/[a0]

Question 5

what must be plotted for 0th order to give a straight line

Answer 5

[a] against t

make sure the reaction has finished completely - any reaction may be seen as 0th if not completed

Question 6

to find k and intercept on 1st order reactions we do

Answer 6

k = multiply gradient by -1
intercept = exp intercept

Question 7

to find k and intercept in 2nd order reactions

Answer 7

k = gradient
intercept = 1/intercept

Question 9

for initial rates what goes on the y axis

Answer 9

ln(R)0

Question 10

for initial rate what goes on the x axis

Answer 10

ln(B)0

Question 11

2 reactants where only 1 conc can be measured method of finding order

Answer 11

isolation method to find conc of the measurable reactant.

initial rates method to find order of the one we can’t measure,, when it’s still in excess. repeat reaction at different initial concentrations