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 of I2: 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
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