kinetics

Question 1

why, even if there are five moles of a molecule, can the order of reaction not be 5

Answer 1

chance of 5 or more ions colliding in RDS is negligible

Question 2

why is total volume kept same when conc changed in rate experiment

Answer 2

so volume is proportional to concentration

Question 3

why is graph depicting 1st order

Answer 3

line through origin
directly proportional

Question 4

units for:
mol dm-3 s-1
————————–
k = moldm-3 x moldm-3

Answer 4

mol2 dm-6

answer: mol-1 dm3 s-1

Question 5

what is purpose of starch in iodine clock reaction

Answer 5

indicator
colour change to blue black shows when reaction is complete so time taken to react can be measured and rate calculated

Question 6

eA equation

Answer 6

eA= - grad x 8.31
—————-
1000

Question 7

graph axis
lnK
1/Temp

Answer 7

1/ T
————————-
lnK I
I
I
I

Question 8

graph axis
volume
1/time

Answer 8

I
I
1/t I
I
———————-
volume

Question 9

devise experiment to compare rate of hydrolysis of halogenoalkanes

Answer 9

ethanol solvent
equal volume and temp using water bath etc
silver nitrate
time to form ppt

Question 10

explain which halogenoalkane (iodo, chloro or bromo) forms ppt the fastest

Answer 10

iodo>bromo>chloro
C-I has weakest bond enthalpy

Question 11

equation for reaction between NO and CO in catalytic converter

Answer 11

2NO + 2CO -> N2 + 2CO2

Question 12

describe the stages of reaction between carbon monoxide and nitrogen monoxide in a catalytic converter

Answer 12

adsorption of cases to catalytic surface
weakens bonds on catalytic surface
desorption of products from catalytic surface

Question 13

role of strach in iodine clock reaction

Answer 13

it is an indicator
time taken to turn blue black can be used to determine rate