IB Chemistry on Kinetics Design IA and uncertainty calculation for rate and order.

http://lawrencekok.blogspot.com

Prepared by Lawrence Kok

IB Chemistry Kinetics and methods to measure for IA and uncertainty calculation for order.

http://lawrencekok.blogspot.com/

Techniques Used to measure Rate of Rxn

Rxn: CaCO3 with HCI measured using THREE diff methods CaCO3 + 2HCI → CaCI2 + CO2 + H2O

• Rate = Δ mass CaCO3 over time• Initial mass recorded

• CaCO3 + 2HCI → CaCI2 + CO2 + H2O • (CaCO3 limiting, HCI excess)• 50ml, 1M HCI into flask • Place on balance• 1g CaCO3, place on balance• Record total mass • Add CaCO3 to flask and start stopwatch • Mass flask recorded every 1 min interval• Repeat using 2M HCI

Method 1 Method 3Method 2

Mass

Time Time Time

Volume Pressure

• Rate = Δ vol CO2 over time• Volume recorded

• Rate = Δ pressure CO2 over time• Pressure recorded

ProcedureTime/m Total

mass(HCI 1M)

Total mass

(HCI 2M)

0 60.00 60.00

1 59.20 58.10

2 58.80 57.70

3 57.50 56.70

4 57.00 55.40

Mass

Time2M HCI

1M HCI


Rxn: CaCO3 with HCI measured using THREE diff methods CaCO3 + 2HCI → CaCI2 + CO2 + H2O


• CaCO3 + 2HCI → CaCI2 + CO2 + H2O • (CaCO3 limiting, HCI excess)• 50ml, 1M HCI into flask • Add 1g CaCO3 to flask and start stopwatch • Vol recorded every 1 min interval• Repeat using 2M HCI


Mass

Time Time Time

Volume Pressure



ProcedureTime/m Vol CO2

(HCI 1M)Vol CO2

(HCI 2M)

0 0.0 0.0

1 8.5 14.0

2 15.0 26.5

3 21.0 34.0

4 26.0 39.0

Volume CO2

Time

2M HCI

1M HCI


Rxn: CaCO3 with HCI measured using THREE diff methods

CaCO3 + 2HCI → CaCI2 + CO2 + H2O


• CaCO3 + 2HCI → CaCI2 + CO2 + H2O • (CaCO3 limiting, HCI excess)• 50ml, 1M HCI into flask • Add 1gCaCO3 to flask and start stopwatch • Press recorded every 1 min interval• Repeat using 2M HCI


Mass

Time Time Time

Volume Pressure



ProcedureTime/m Pressure

CO2(HCI 1M)

Pressure CO2

(HCI 2M)

0 101.3 101.3

1 102.4 103.4

2 103.5 105.6

3 110.3 115.2

4 113.5 118.2

Pressure CO2

Time

2M HCI

1M HCI


• Rate = Δ mass Sulfur over time

Method 1 Method 2

Mass

Time Time

Light Intensity

• Rate = Δ light intensity over time• Light intensity recorded

Procedure Conc/MS2O3

2- Time/s Rate

1/Time

0.2 80.8 1/80.8 = 0.0123

0.4 40.2 1/40.2 = 0.0248

0.6 25.2 1/25.2 = 0.0396

0.8 20.5 1/20.5 = 0.0487

1.0 18.2 1/18.2 = 0.0550

Rate = 1/time

Conc

Rxn: Na2S2O3 with HCI measured using TWO diff methodsNa2S2O3 + 2HCI → 2NaCI2 + SO2 + H2O + S

• Na2S2O3 + 2HCI → 2NaCI2 + SO2 + H2O + S • (Na2S2O3 limiting, HCI excess)• 50ml 0.2M HCI into conical flask• Place on top of paper with cross X• Pour 5ml 0.1M Na2S2O3 into flask• Record time for X to disappear• Repeat with diff S2O3

2- conc

Light sensor

Light source

0.2 0.4 0.6 0.8

• Na2S2O3 + 2HCI → 2NaCI2 + SO2 + H2O + S • (Na2S2O3 limiting, HCI excess)• Pipette 1ml 0.2M S2O3

2- into cuvette• Pipette 0.1ml 0.1M HCI into cuvette• Mix and start light sensor• Record time for light intensity to drop• Repeat with diff S2O3

2- conc


• Rate = Δ mass Sulfur over time

Method 1 Method 2

Mass

Time Time

Light Intensity

• Rate = Δ light intensity over time• Light intensity recorded

Procedure Conc/MS2O3

2- Time/s Rate

1/Time

0.2 80.8 1/80.8 = 0.0123

0.4 40.2 1/40.2 = 0.0248

0.6 25.2 1/25.2 = 0.0396

0.8 20.5 1/20.5 = 0.0487

1.0 18.2 1/18.2 = 0.0550

Rate = 1/time

Rxn: Na2S2O3 with HCI measured using TWO diff methods

Na2S2O3 + 2HCI → 2NaCI2 + SO2 + H2O + S

Light source

Light sensor

Light intensity

0.8M S2O3

2- 1M S2O3

2-

Conc

0.2 0.4 0.6 0.8 18.2 20.3 time

• H2O2 + 2KI + 2HCI → 2KCI + 2H2O + I2 (KI limiting, H2O2 excess)• Pipette 5ml 3% H2O2, 5ml 0.1M HCI into flask• Add starch, 1ml 0.1M S2O3 to flask• Place on white paper with cross X • Pipette 5 ml 0.1M KI into flask• Record time for X to disappear• Repeat with diff KI conc


Method 1 Method 2

Mass iodine produced

Time Time

Absorbance

• Rate = Δ Absorbance over time• Absorbance recorded

Procedure Conc/MKI

Time/s Rate1/Time

0.00625 80.8 1/80.8 = 0.0123

0.0125 40.2 1/40.2 = 0.0248

0.025 25.2 1/25.2 = 0.0396

0.05 20.5 1/20.5 = 0.0487

0.1 18.2 1/18.2 = 0.0550

Rate = 1/time

Conc

Rxn: H2O2 with I - measured using TWO diff methods

H2O2 + 2I- + 2H+ → 2H2O + I2Iodine Clock Rxn

H2O2 + 2I - + 2H+ → 2H2O + I2I2 + 2S2O3

2- → S4O6 2- + 2I -

I2 + starch → Blue black

H2O2 - Oxidising AgentI - - Reducing AgentS203

2- - Reduce I2 to I –I2 - I2 react with starch form blue black• Rate = Δ mass iodine over time

= Disappearance X due to blue black formation

Abs increase when blue black

form

0.025 0.05 0.1

• H2O2 + 2KI + 2HCI → 2KCI + 2H2O + I2 (KI limiting, H2O2 excess)• Pipette 0.5ml 3% H2O2, 0.1M HCI to cuvette• Add starch, 0.1ml 0.1M S2O3 to cuvette• Pipette 0.5ml 0.2M KI to cuvette• Record Abs change• Repeat with diff KI conc


Method 1 Method 2


Time Time

Absorbance


Procedure Absorbance

Time


form

Rxn: H2O2 with I - measured using TWO diff methods

H2O2 + 2I- + 2H+ → 2H2O + I2Iodine Clock Rxn

H2O2 + 2I - + 2H+ → 2H2O + I2I2 + 2S2O3

2- → S4O6 2- + 2I -


H2O2 - Oxidising AgentI - - Reducing AgentS203

2- - Reduce I2 to I –I2 - I2 react with starch form blue black• Rate = Δ mass iodine over time

= Disappearance X due to blue black formation

Time Conc KI

(0.2)Abs

Conc KI

(0.4)Abs

Conc KI

(0.6)Abs

Conc KI

(0.8)Abs

0 0.1 0.1 0.1 0.1

2 0.1 0.1 0.1 0.1

4 0.1 0.1 0.1 1.4

6 0.1 0.1 1.2

8 0.1 0.1

10 0.1 1.3

12 0.1

Rate 1/14= 0.07

1/10= 0.1

1/6= 0.16

1/ 4= 0.25

000000.2M KI0.8M KI

4 6 10 12


Method 1 Method 2


Time Time

Absorbance


Procedure Conc KI/M

Time/s Rate1/Time

0.00625 80.8 1/80.8 = 0.0123

0.0125 40.2 1/40.2 = 0.0248

0.025 25.2 1/25.2 = 0.0396

0.05 20.5 1/20.5 = 0.0487

0.1 18.2 1/18.2 = 0.0550

Rate = 1/time

Conc

Rxn: S2O82- with I - measured using TWO diff methods

Iodine Clock Rxn

S2O82 - Oxidising

AgentI - - Reducing AgentS203

2- - Reduce I2 to I –I2 - I2 react with starch form blue black

• Rate = Δ mass iodine over time = Disappearance X due to blue black formation


form

S2O82- + 2I - → 2SO4

2- + I2

S2O82- + 2I - → 2SO4

2- + I2I2 + 2 S203

2- → S406 2- + 2I -


• S2O82- + 2I - → 2SO4

2- + I2 (KI limiting, S2O8

2- excess)• Pipette 5ml 0.1M KI, 0.1M S2O3 • Add 1ml starch to flask• Place on white paper with cross X • Pipette 5 ml 0.1M S2O8

2- to flask• Record time for X to disappear• Repeat with diff KI conc

0.0125 0.025 0.05 0.1

• S2O82- + 2I - → 2SO4

2- + I2 (KI limiting, S2O8

2- excess)• Pipette 0.5ml 0.1M KI, 0.1M S2O3 to cuvette• Add 0.1ml starch to cuvette• Pipette 0.5ml 0.1M S2O8

2- to cuvette• Record Abs change• Repeat with diff KI conc


Method 1 Method 2


Time Time

Absorbance


Procedure

Rxn: S2O82- with I - measured using TWO diff methods

Iodine Clock Rxn

S2O82 - Oxidising

AgentI - - Reducing AgentS203

2- - Reduce I2 to I –I2 - I2 react with starch form blue black

• Rate = Δ mass iodine over time = Disappearance X due to blue black formation


form

S2O82- + 2I - → 2SO4

2- + I2

S2O82- + 2I - → 2SO4

2- + I2I2 + 2 S203

2- → S406 2- + 2I -


Time Conc KI

(0.2)Abs

Conc KI

(0.4)Abs

Conc KI

(0.6)Abs

Conc KI

(0.8)Abs

0 0.1 0.1 0.1 0.1

2 0.1 0.1 0.1 0.1

4 0.1 0.1 0.1 1.4

6 0.1 0.1 1.2

8 0.1 0.1

10 0.1 1.3

12 0.1

Rate 1/14= 0.07

1/10= 0.1

1/6= 0.16

1/ 4= 0.25

Absorbance

Time

0.8M KI00000000000.2M KI

4 6 10 12


Method 1 Method 2

Time Time

Volume Pressure

• Rate = Δ vol O2 over time• Volume recorded

• Rate = Δ pressure O2 over time• Pressure recorded

Procedure

2H2O2 → O2 + 2H2ORxn: H2O2 with KI (catalyst) measured using TWO diff methods

• 2H2O2 → O2 + 2H2O (H2O2 limiting, KI excess)• Pipette 1ml 1.0M KI to 20ml of 1.5% H2O2 • Vol O2 released recorded at 1 min interval• Repeated using 3% H2O2 conc

Time/m Vol O2(H2O2 1.5%)

Vol O2(H2O2 3.0%)

0 0.0 0.0

1 8.5 14.0

2 15.0 26.5

3 21.0 34.0

4 26.0 39.0

Volume O2

Time

3 %

1.5 %

• 2H2O2 → O2 + 2H2O (H2O2 limiting, KI excess)• Pipette 1ml 1.0M KI to 20ml of 1.5% H2O2 • Pressure O2 released recorded at 1 min interval• Repeat using 3% H2O2 conc


Method 1 Method 2

Time Time

Volume Pressure

• Rate = Δ vol O2 over time• Volume recorded

• Rate = Δ pressure O2 over time• Pressure recorded

Procedure

2H2O2 → O2 + 2H2O

Time

3 %

1.5 %

Time/m Pressure O2(H2O2 1.5%)

Pressure O2

(H2O2 3%)

0 101.3 101.3

1 102.4 103.4

2 103.5 105.6

3 110.3 115.2

4 113.5 118.2

Pressure O2

Rxn: H2O2 with KI (catalyst) measured using TWO diff methods

• Rate = Δ Conc I2 over time• Conc recorded using titration


Method 1 Method 2

Conc iodine produced

Time Time

Absorbance


ProcedureAbsorbance

Time

Abs increase when iodine

form

2Fe3+ + 2I - → 2Fe2+ + I2

Rxn: Fe3+ + I - measured using TWO diff methods

Fe 3+ - Oxidising Agent

I - - Reducing Agent

• 2Fe3+ + 2I - → 2Fe2+ + I2 • (I - limiting, Fe3+ excess)• Pipette 1.5ml 0.02M Fe3+to cuvette. • Find λ max for Fe3+ (450nm)• Abs vs time , select λ = 450nm• Pipette 1.0ml 0.02M KI to cuvette• Measure abs increase due to I2 formation• Repeat using diff KI conc

Time/s Conc 0.02M KIAbs

Conc 0.04M KIAbs

0 0.240 0.240

1 0.245 0.260

2 0.257 0.330

3 0.300 0.390

4 0.330 0.540

0.04 M

0.02 M

• 2Fe3+ + 2I - → 2Fe2+ + I2 (I - limiting, Fe3+ excess)• Pipette 25ml 0.02M KI /Fe3+ to flask. • Start time• Every 5min, pipette 10ml sol mix to flask • Titrate with S2O3

2-

( I2 form will react with S2O32-)

Amt I2 produced is determine.• I2 + 2S203

2- → S4O62- + 2I – (Mol ratio 1:2)

• Rate = Δ Conc I2 over time• Conc recorded using titration


Method 1 Method 2

Conc iodine produced

Time Time

Absorbance


Procedure

Conc I2

Time

2Fe3+ + 2I - → 2Fe2+ + I2

Rxn: Fe3+ + I - measured using TWO diff methods

Fe 3+ - Oxidising Agent

I - - Reducing Agent

Time/m

Vol S2O3/ cm3

Conc I2/M

0 0 0

5 6 0.06

10 18 0.18

15 28 0.28

20 28 0.28

25 ml 0.02M KI/Fe3+

10ml removed every 5m

0.2M S2O33-

Contain I2

2S2032- + I2 → S4O6

2- + 2I –

2 mol S2032 – 1 mol I2

0.0012 mol – 0.006 mol I2

Vol S2032- 6.0ml – Amt S203

2- = M x V = 0.2 x 0.006 = 0.0012 mol

Conc I2 = Amt I2/Vol = 0.0006/0.01 = 0.06 M

• I2 + CH3COCH3 → CH3COCH2I + H+ + I – (CH3COCH3 limiting, I2

excess)• Pipette 1ml 0.002M I2 to cuvette. • Abs vs Time (λ max = 520nm)• Pipette 0.4ml 2M HCI and 1ml water to cuvette• Pipette 0.4ml 0.2M CH3COCH3 to cuvette • Record drop in abs over time• Repeat using diff CH3COCH3 conc

• Rate = Δ Conc I2 over time• Conc recorded


Method 1 Method 2

Conc iodine

Time Time

Absorbance I2


Procedure

Time

Abs decrease I2 consumed

I2 + CH3COCH3 → CH3COCH2I + H+ + I -

Rxn: I2 + CH3COCH3 measured using TWO diff methods

Time Conc (0.2M)

Abs

Conc (0.4M)

Abs

Conc (0.6M)

Abs

0 2.00 2.00 2.00

2 1.86 1.76 1.52

4 1.75 1.54 1.20

6 1.57 1.24 0.78

8 1.23 1.23 0.56

10 1.10 0.78 0.40

Rate Gradient

Time 0

Gradient

Time 0

Gradient

Time 0

Absorbance I2

0.2 M0.4 M0.6 M

Conc CH3COCH3

Rate

• Rate = Δ Conc I2 over time• Conc obtain from std calibration plot


Method 1 Method 2

Conc iodine

Time Time

Absorbance I2


Procedure

I2 + CH3COCH3 → CH3COCH2I + H+ + I -

Rxn: I2 + CH3COCH3 measured using TWO diff methods

Time Conc I2(0.2M)

Abs

Conc I2(0.4M)

Abs

Conc I2(0.6M)

Abs

0 2.00 2.00 2.00

2 1.86 1.76 1.52

4 1.75 1.54 1.20

6 1.57 1.24 0.78

Absorbance I2

0.2 M0.4 M0.6 M

Conc I2• I2 + CH3COCH3 → CH3COCH2I + H+ + I – (CH3COCH3 limiting, I2

excess)• Pipette 1ml 0.002M I2 to cuvette. • Prepare std calibration plot Abs vs I2 conc• Abs vs Time (λ max = 520nm)• Pipette 0.4ml 2M HCI and 1ml water to cuvette• Pipette 0.4ml 0.2M CH3COCH3 to cuvette • Record drop in abs over time• Repeat using diff I2 conc

Convert Abs I2 to conc I2 using std calibration curve

Time0.2 M0.4 M0.6 M

Conc I2 Abs

0 0

0.125 0.3

0.25 0.5

0.5 0.7

1.0 1.1

Std calibration curve

Time

Graphical Representation of Order :ZERO, FIRST and SECOND order

ZERO ORDER FIRST ORDER SECOND ORDER

Rate – 2nd order respect to [A]Conc x2 – Rate x 4Unit for k Rate = k[A]2

Rate = kA2

k = M-1s-1

Rate

Conc reactant

Rate

Conc reactant Conc reactant

Conc Conc Conc

Time Time Time

Time

Conc reactant

Rate

Time

ln At

Time

1/At

ktAA ot ][][

Rate = k[A]0

Rate independent of [A]Unit for k Rate = k[A]0

Rate = kk = Ms-1

Rate vs Conc – Constant

Conc vs Time – Linear

Rate = k[A]1

Rate - 1st order respect to [A]Unit for k Rate = k[A]1

Rate = kAk = s-1

Rate vs Conc - proportional

Conc vs Time

ktAAeAA

ot

ktot

]ln[]ln[][][

[A]t

[A]o

ktAA ot

][1

][1

ln Ao

1/Ao

Conc at time t Conc at time t

Using 2nd method to find order

Determination order: Na2S2O3 + 2HCI → NaCI + H2O + S + SO2

Order of Na2S2O3 Conc Na2S2O3 changes, fix [HCI] = 0.1M

Na2S2O3 addedHCI was added

Time taken X fade away

ConcNa2S2O3

Time/sTrial 1±0.01

Time/sTrial 2±0.01

Time/sTrial 3±0.01

Average time

Rate

0.05 102.96 103.23 114.80 107.00 0.00046

0.10 45.43 44.08 38.35 42.62 0.0023

0.15 27.36 27.13 26.36 26.95 0.0055

0.20 18.06 18.57 17.53 18.05 0.0111

0.25 15.26 15.44 16.88 15.86 0.0158

Result expt

00046.010705.0

.

timeAveConcRate

Cal for Conc 0.05M

4 ways for uncertainty rate

1st methodAve time = (107.00 ± 0.01)% uncertainty time = 9.34 x 10-3 %%∆ Rate = %∆ TimeRate = 0.00046 ± 9.34 x 10-3 % = 0.00046 ± 0.000000043

Too smallPoor choice

4th methodUncertainty rate = (Max – min) for rateRate 1 = Conc/time 1 = 0.05 / 102.96 = 0.00049Rate 2 = Conc/time 2 = 0.05 / 103.23 = 0.00048Rate 3 = Conc/ time 3 = 0.05 / 114.80 = 0.00043Max rate = 0.00049Min rate = 0.00043Range = (Max – Min)/2 Range = (0.00049 – 0.00043)/2 = 0.00003Average rate = (R1 + R2 + R3)/3 = 0.00047 ± 0.00003

ConsistentGood choice

3rd methodUncertainty rate = std deviation (for conc 0.05)Rate 1 = Conc/time 1 = 0.05 / 102.96 = 0.00049Rate 2 = Conc/time 2 = 0.05 / 103.23 = 0.00048Rate 3 = Conc / time 3 = 0.05 / 114.80 = 0.00043Average rate = (R1 + R2 + R3)/3 = 0.00047 ± std dev = 0.00047 ± 0.000032


2nd methodUsing Range (Max – Min) for timeRange = (Max – Min) for time/2Range = (114.80 – 102.96)/2 = 5.92Ave time = (107.00 ± 5.92)% uncertainty time = 5.5%% ∆Rate = %∆TimeRate = 0.00046 ± 5.5% = 0.00046 ± 0.000026


Determination order : Na2S2O3 + 2HCI → NaCI + H2O + S + SO2

Order of Na2S2O3 Conc Na2S2O3 changes, fix [HCI] = 0.1M

Na2S2O3 addedHCI was added

Time taken X fade away

ConcNa2S2O3

Time/sTrial 1±0.01

Time/sTrial 2±0.01

Time/sTrial 3±0.01

Average time

Rate

0.05 102.96 103.23 114.80 107.00 0.00046

0.10 45.43 44.08 38.35 42.62 0.0023

0.15 27.36 27.13 26.36 26.95 0.0055

0.20 18.06 18.57 17.53 18.05 0.0111

0.25 15.26 15.44 16.88 15.86 0.0158

Result expt

00046.000.10705.0

.

timeAveConcRate

Cal for Conc 0.05M

2nd methodUsing Range (Max – Min) for timeRange = (Max – Min)/2Range = (114.80 – 102.96)/2 = 5.92Ave time = (107.00 ± 5.92)% uncertainty time = 5.5%% ∆Rate = %∆TimeRate = 0.00046 ± 5.5% = 0.00046 ± 0.000026


Uncertainty rate for conc 0.05M

ConcNa2S2O3

Time/sTrial 1±0.01

Time/sTrial 2±0.01

Time/sTrial 3±0.01

Average time

± Time Range (Max- Min)/2

% ±Time Rate(±rate)

0.05 102.96 103.23 114.80 107.00 (114.8-102.96)/2 = 5.92

5.5% 0.00046 ±0.000026

0.10 45.43 44.08 38.35 42.62 (45.43 – 38.35)/2 = 3.54

8.3% 0.0023 ±0.00027

0.15 27.36 27.13 26.36 26.95 (27.13 – 26.36)/2 = 0.50

1.8% 0.0055 ±0.00022

0.20 18.06 18.57 17.53 18.05 (18.06 – 17.53)/2 = 0.52

2.8% 0.0111 ±0.0006

0.25 15.26 15.44 16.88 15.86 (16.88 – 15.26)/2 = 0.81

5.1% 0.0158 ±0.0011


Plot of Conc vs Rate

ConcNa2S2O3

Rate(±rate)

0.05 0.00046 ±0.0000026

0.10 0.0023 ±0.00027

0.15 0.0055 ±0.00022

0.20 0.0111 ±0.0006

0.25 0.0158 ±0.0011

Order for Na2S2O3 (fix conc HCI)Let Rate = k[Na2S2O3]x [HCI] y

Rate

Conc Na2S2O3

Uncertainty rate

Conc Na2S2O3

Rate

Best fit Order = 2.21


Max fit Order = 2.29

Min fit Order = 2.12

Lowest uncertainty (Lowest Conc) to Highest uncertainty (Highest Conc)

Highest uncertainty (Lowest Conc) to Lowest uncertainty (Highest Conc)

Max order

Min order


ConcNa2S2O

3

Rate(±rate)

0.05 0.00046 ±0.0000026

0.10 0.0023 ±0.00027

0.15 0.0055 ±0.00022

0.20 0.0111 ±0.0006

0.25 0.0158 ±0.0011

ConcNa2S2O

3

Rate(±rate)

0.05 0.00044

0.10 0.00221

0.15 0.0055

0.20 0.0114

0.25 0.017

Max order


Max order – Lowest uncertainty (Lowest Conc) to Highest uncertainty (Highest Conc)

ConcNa2S2O

3

Rate(±rate)

0.05 0.00046 ±0.0000026

0.10 0.0023 ±0.00027

0.15 0.0055 ±0.00022

0.20 0.0111 ±0.0006

0.25 0.0158 ±0.0011

Min order

ConcNa2S2O

3

Rate(±rate)

0.05 0.00048

0.10 0.00248

0.15 0.0055

0.20 0.0108

0.25 0.0147

Conc Na2S2O3

Conc Na2S2O3

Rate

Rate


Min order – Highest uncertainty (Lowest Conc) to Lowest uncertainty (Highest Conc)

Highest uncertainty 0.0158 + 0.0011 = 0.017

Lowest uncertainty0.00046 – 0.000026= 0.00044

Highest uncertainty0.00046 + 0.000026= 0.00048

Lowest uncertainty0.0158 – 0.0011= 0.0147

Lowest uncertainty

Highest uncertainty

Lowest uncertainty

Highest uncertainty

Max order

Min order

Order respect to Na2S2O3 = 2.21Theoretical order = 2.00% Error order = 10.7%


ConcNa2S2O3

Rate(±rate)

0.05 0.00046 ±0.0000026

0.10 0.0023 ±0.00027

0.15 0.0055 ±0.00022

0.20 0.0111 ±0.0006

0.25 0.0158 ±0.0011

Order for Na2S2O3 (fix conc HCI)Let Rate = k[Na2S2O3]x [HCI] 1

Order x = 2.21Conc Na2S2O3

Rate Best fit Order = 2.21



Uncertainty order = (Max order – Min order)/2

%7.10%10000.2

)00.221.2(

± Uncertainty for order = (Max – Min order)/2Max order = 2.29Min order = 2.12± Uncertainty order(Max – Min)/2 = ( 2.29 – 2.12)/2 = 0.09

± Uncertainty order = 2.21 ± 0.09% uncertainty order = (0.09/2.21) x 100 % = 4%

% Error order = 10.7%

% Uncertainty(Random Error)

% Uncertainty(Systematic Error)

4%

% Error = % Random + % Systematic error error% Systematic = (10.7 – 4 )= 6.7% error

Correct Method !

Order respect to Na2S2O3 = 2.21Theoretical order = 2.00% Error order = 10.7%


ConcNa2S2O3

Rate(±rate)

0.05 0.00046 ±0.0000026

0.10 0.0023 ±0.00027

0.15 0.0055 ±0.00022

0.20 0.0111 ±0.0006

0.25 0.0158 ±0.0011

Order for Na2S2O3 (fix conc HCI)Let Rate = k[Na2S2O3]x [HCI] 1

Order x = 2.21Conc Na2S2O3

Rate


% Uncertainty rate = % Uncertainty time = 5.5%

%7.10%10000.2

)00.221.2(

% Error order = 10.7%

% Uncertainty(Random Error)

% Uncertainty(Systematic Error)

5.5%

ConcNa2S2O

3

Time/sTrial 1±0.01

Time/sTrial 2±0.01

Time/sTrial 3±0.01

Average time

± Time Range (Max- Min)/2

% ±Time

0.05 102.96 103.23 114.80 107.00 (114.8-102.96)/2 = 5.92

5.5%

0.10 45.43 44.08 38.35 42.62 (45.43 – 38.35)/2 = 3.54

8.3%

0.15 27.36 27.13 26.36 26.95 (27.13 – 26.36)/2 = 0.50

1.8%

0.20 18.06 18.57 17.53 18.05 (18.06 – 17.53)/2 = 0.52

2.8%

0.25 15.26 15.44 16.88 15.86 (16.88 – 15.26)/2 = 0.81

5.1%Wrong Method !

% Error = % Random + % Systematic error error% Systematic = (10.7 – 5.5)= 5.2 % error

Acknowledgements

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Thanks to Creative Commons for excellent contribution on licenseshttp://creativecommons.org/licenses/

Prepared by Lawrence Kok

Check out more video tutorials from my site and hope you enjoy this tutorialhttp://lawrencekok.blogspot.com

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IB Chemistry on Kinetics Design IA and uncertainty calculation for rate and order.

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Transcript of IB Chemistry on Kinetics Design IA and uncertainty calculation for rate and order.