# Sasmsung Poter 5 Forces

Topics: Chemical kinetics, Iodine clock reaction, Chemical clock Pages: 7 (630 words) Published: April 17, 2013
CHM1022 Lab Report 1

Rate Law of an Iodine Clock Reaction

Name: Sashini Naomi Wijesekera
Student ID: 23877847

Lab Partner: Zahiya Imam

Lab Session: Monday 9.00am
Aim

The aim of the experiment is to determine the factors that affect the rate of a reaction, by performing the iodine clock reaction and repeating it changing different initial conditions in order to measure and compare the rate of reaction for each experiment and experimentally determine the rate law.

Method

Refer CHM1022 Laboratory Manual, Semester 1 2013.

Results and Calculations-

Part A- Calculations of rate for one set of conditions

1. n(S2O32-)=CV
=0.0025M*(10/1000)L
=2.50*10-5mol

Molar ratio of I2 : S2O32- = 1 : 2

n(I2)=0.5*n(S2O32-)
=0.5*(2.50*10-5mol)
=1.25*10-5mol

Mean time taken for blue colour to appear = (131sec+135sec+145sec)/3 =137seconds

Rate of reaction=n(I2)/t
=(1.25*10-5mol/137sec)
=9.12*10-8mols-1

[H2O2]: C1V1=C2V2
0.8*1=C2*99
C2=8.08*10-3M

[I-]: C1V1= C2V2
0.025*10=C2*99
C2=2.53*10-3M

[H30+]: C1V1= C2V2
0.36*35=C2*99
C2=0.127M

[S2O32-]: C1V1= C2V2
0.0025*10=C2*99
C2=2.53*10-4M

Part B-Results and calculations

B4 (i)

n(S2O32-) = 0.0025*(5/1000)
= 1.25*10-5mol

Molar ratio of I2 : S2O32-=1: 2
n(I2)=0.5*n(S2O32-)
n(I2)= 0.5*(1.25*10-5)
=6.25*10-6mol

B4 (ii)
n(S2O32-)= 0.0025*(20/1000)
= 5*10-5mol

Molar ratio ofI2: S2O32-=1:2
n(I2)=0.5*n(S2O32-)
n(I2)=0.5*(5.0*10-5)
=2.5*10-5mol

Part B-Results and calculations
| | | | | | | |Time/s |n(I2)/mol |Rate/mol s-1 |Concentration/M | | | | | | | | | | | | | | | | | | | | | | | | |

|1 |2 |3 |4 |5 |6 |Mean time/s | | | | |B1[H202]
(i)higher

(ii)lower

|
66 |
63 |
61 |
67 |
69 |
60 |
64 |
1.25*10-5 |
(1.25*10-5)/64=1.95*10-7 |[H2O2]:
C1V1= C2V2
0.8*2=C2*99
C2=0.016 | | |
249 |
287 |
242 |
262 |
252 |
260 |
259 |
1.25*10-5 |
(1.25*10-5)/259=4.83*10-8 |[H2O2]:
C1V1= C2V2
0.8*0.5=C2*99
C2=4.0*10-3 | |B2[I-]
(i)higher

(ii)lower |
78 |
-- |
78 |
87 |
-- |
-- |
81 |
1.25*10-5 |
(1.25*10-5)/81=1.54*10-7 |[I2]:
C1V1= C2V2
0.025*20=C2*99
C2=5.1*10-3 | | |
-- |
252 |
288 |
261 |
-- |
-- |
267 |
1.25*10-5 |
(1.25*10-5)/267=4.68*10-8 |[I2]:
C1V1= C2V2
0.025*5=C2*99
C2=1.26*10-3 | |B3[H30+]
(i)higher

(ii)lower |
91 |
-- |
92 |
94 |
-- |
-- |
92 |
1.25*10-5 |
(1.25*10-5)/92=1.36*10-7 |[H30+]:
C1V1= C2V2
0.36*70=C2*99
C2=0.255 | | |
206 |
226 |
221 |
207 |
-- |
-- |
215 |
1.25*10-5 |
(1.25*10-5)/215=5.81*10-8 |[H30+]:
C1V1= C2V2
0.36*17.5=C2*99
C2=0.064 | |B4[S2032-]
(i)lower

(ii)higher
|
61 |
67 |
71 |
69 |
-- |
-- |
67 |
6.25*10-6 |
(6.25*10-6)/67=9.33*10-8 |[S2032-]:...