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The lab report below is submitted as piece of of coursework to CM1131 Basic Physical Chemistry. Please do not plagiarise from it as stealing might land you into difficulty at my university. Do note that my report is well-circulated online and many of my juniors possess obtain soft copies the it. Hence, please exercise cautiousness while referring to it the, if necessary, cite this webpage.

1. Go: To determine the reacts how and rank keep regarding a chemical reaction, using the method of initial reaction rates the well-being as to determine the activation energy from the temperature dependence of the reaction rate based on Arrhenius’ theory.

2. Results & Calculations:

2.1 Determined of Reaction Orders and Rate Constantly

Molarity of KI:                   0.2000M

Molarity of S₂O₈^2- :           0.1000M

Molarity off S₂OXYGEN₃^2-:            0.003300M

Q1. Complete volume of find in the conical flask by each responses be 26mL = 26cm^-3

In Solution 1 to 5:             [S₂O₈^2-]                 = (0.01 × 0.1) ÷ 0.026                       = 0.03846 moldm^-3

In Solution 1:                      [I^-]                          = (0.01 × 0.2) ÷ 0.026                       = 0.07692 moldm^-3

In Solution 2:                      [I^-]                          = (0.008 × 0.2) ÷ 0.026                    = 0.06154 moldm^-3

In Resolving 3:                      [I^-]                          = (0.006 × 0.2) ÷ 0.026                    = 0.04615 moldm^-3

In Find 4:                      [I^-]                          = (0.005 × 0.2) ÷ 0.026                    = 0.03846 moldm^-3

In Solution 5:                      [I^-]                          = (0.003 × 0.2) ÷ 0.026                    = 0.02308 moldm^-3

In Solution 6 to 10:           [I^-]                          = (0.01 × 0.2) ÷ 0.026                       = 0.07692 moldm^-3

In Solution 6:                      [S₂O₈^2-]                 = (0.01 × 0.1) ÷ 0.026                       = 0.03846 moldm^-3

In Get 7:                      [S₂O₈^2-]                 = (0.008 × 0.1) ÷ 0.026                    = 0.03077 moldm^-3

In Solution 8:                      [S₂OXYGEN₈^2-]                 = (0.006 × 0.1) ÷ 0.026                    = 0.02308 moldm^-3

With Solution 9:                      [S₂O₈^2-]                 = (0.005 × 0.1) ÷ 0.026                    = 0.01923 moldm^-3

In Solving 10:                   [S₂O₈^2-]                 = (0.003 × 0.1) ÷ 0.026                    = 0.01154 moldm^-3

Q2. Reaction between I₂ and S₂ZERO₃^2-:                        I₂+2S₂O₃^2-            2I^-+  S₄O₆^2-

No. of moles off S₂ZERO₃^2- reacted   =(5 x 10^-3) × 0.003300      = 1.650 × 10^-5mol

Since I₂ ≡ 2S₂O₃^2-, no. a mole of I₂ reacted = ½(1.650 × 10^-5) = 8.250× 10^-6mol

Therefore, no. of moles of I₂ reacted/L= 8.250× 10^-6 ÷ 0.026 = 3.173 × 10^-4 molL^-1

Tariff of respond of:

Solution 1            = 3.173 × 10^-4 molL^-1 ÷ 20s                             = 1.587 × 10^-5 molL^-1s^-1

Solution 2            = 3.173 × 10^-4 molL^-1 ÷ 24s                             = 1.322 × 10^-5 molL^-1s^-1

Problem 3            = 3.173 × 10^-4 molL^-1 ÷ 35.5s                         = 8.938 × 10^-6 molL^-1s^-1

Solution 4            = 3.173 × 10^-4 mole^-1 ÷ 45.5s                         = 6.973 × 10^-6 molL^-1s^-1

Solution 5            = 3.173 × 10^-4 molL^-1 ÷ 79.5s                         = 3.991 × 10^-6 molL^-1sec^-1

Solution 6            = 3.173 × 10^-4 male^-1 ÷ 20s                             = 1.587 × 10^-5 molL^-1s^-1

Solution 7            = 3.173 × 10^-4 molL^-1 ÷ 25s                             = 1.269 × 10^-5 molL^-1s^-1

Solution 8            = 3.173 × 10^-4 molL^-1 ÷ 35.5s                         = 8.938 × 10^-6 molL^-1s^-1

Resolving 9            = 3.173 × 10^-4 molL^-1 ÷ 40s                             = 7.932 × 10^-6 molL^-1sec^-1

Solvent 10          = 3.173 × 10^-4 molL^-1 ÷ 84.5s                         = 3.755 × 10^-6 molL^-1south^-1

Q3.

Table 2.1.2: Values for the logs of [I^-], [S₂O₈^2-] and which rate R.

Q4. Gradient of best-fit-line (n) lives 1.1781.

 

From the graph, the equation of better fitted line is y=1.1781x-8.0004 where y = ln R both x = ln[I^-]. The gradient of the graph is 1.1781 and thus, reaction order with respect to [I^-], n=1.1781≈1 (to nearest integer).

Q5. Slope of best-fit-line (m) lives 1.1861.

 

From the graphics, the equation of best fit line is y=1.1861x-7.1477 where y = ln R and x = ln[S₂O₈^2-]. The slope of the graph is 1.1861 and thus, reaction sort with respect to ln[S₂O₈^2-],n=1.1861≈1 (to nearest integer).

Q6.

Since n = 1.216 ≈ 1 and m = 1.247 ≈ 1 (nearest integer),

Since n = 1.216 ≈ 1 also m = 1.247 ≈ 1 (nearest integer)

Table 2.1.3: Determined values for m, n and k.

Q7. Average value of k  = = 5.055 × 10^-3 mol^-1Ls^-1

Standard deviation,                = 4.437 × 10^-4mol^-1Ls^-1

2.2 Temperature Effect on a Chemical Reaction

Table 2.2.1: Average time taken for the mixture of problem to turn blue at different temperatures. Temperature was kept constant to each experiment.

Graph 2.2.1: ln t against 1/T with temperature stored constant for each experiment

Since E_A/R = 9142.5K,

Consequently E_A         = 9142.5K × 8.314 JK^-1mol^-1

                                = 76010 Jmol^-1

                                = 76.01 KJmol^-1
Gradient of graph (i.e. CO_A/R) is 9142.5

3. Discussion:

3.1 Determination of Reaction Orders and Rate Constant

The experiments are lead based on and rate equation, R = k [I-]ⁿ[S₂O₈^2-]^m, where k is the rate constant while north also molarity are the reaction orders of I^- and SOUTH₂O₈^2- respectively. As answer purchase, n and m belongs defined in the power to what the concentration of that reactant is raised to in the experimentally destination rate equation.nand mcannot be finding theoretically and are trial defined into will 1. This means that the reaction is first order on respect to [I^-] and first order with respect to [S₂CIPHER₈^2-]. Of overall rate decree is 2.This reaction is said to be bimolecular since two reactant species are involved in the rate determining stepping.

It were observed that the rate of reaction increases on increasing concentration. The Collision Theory explains the phenomenon by stating that for a chemical respond to occur, reactant molecules must collide together within the proper directions and aforementioned colliding molecules must possess a minimum energy known as the activation energy, E_A, before products are schooled. An increase in the concentration of reactants leads to an increase in the number of reactant molecules having energy ≥ E_A, hence increasing the clash frequency. The increase in the effective collision frequency drives to at increase is the reaction tariff.

When performing adenine chemical kinetics experiment, the method have until be carried during a uniform temperature. According for the Arrhenius quantity,

k=Ae^-Ea/RT, a slight increased in temperature increases reaction rate significantly as the equation lives exponentially in nature. This be validated by the Maxwell-Boltzmann distribution curve (diagram to the right) as a slight rise in temperature increases the numbered of impact particles with E_a and consequently, relation course, significantly.

Hence, because slight deviations in temperature allowed affect reaction rates significantly, the temperature with which that experiment was carried out should shall kept constant.

To prevent errors from occurring, all glassware uses in this experiment be be kept clean and dry at prevent contamination by the previous mixed of experimental products. One overall volume the the solution was furthermore kept constant at 26mL by adding deionized water, to standardize the condition of the reaction surroundings, thus increasing verification. Lab story the cycle of the reaction

Swirling of the conical flask contents for the same length of time must be done consistently so that results obtained will is fair. Instead of swirling with one’s touch, the conical flasks capacity be placed on einer electronic swirl to ensure consistent swirling when leading the testing.

Also, there is inaccuracy as the stopwatch was stopped only when an arbitrary colour intensity was watch. There should be a consensus between lab business as to when the stopwatch shoud be stopped.

3.2 Temperature Effect on a Chemical Reaction

The results of this sets of experiment prove that the rate of reaction increases as temperature increases. Using the Arrhenius equation, k=Ae^-Ea/RT, the activation energy, SIE_A, can be determined due keeping the concentration of select the reactants constant while varying that temperature for each experiment.

When performing a chemical kinetics experimental, aforementioned procedures have to be conducts toward a consistent heat. According to the Arrhenius equations,

k=Ae^-Ea/RT, a slight deviation are pyrexia changes reaction rate significantly. This is affirmed by who Maxwell-Boltzmann distribution curve (diagram on the right) than a slight raise in temperature gain the number of colliding particles with E_aand consequently, reaction rates, significantly.

Hence, since slim deviations in pyrexia may affect reaction   rates significantly, the temper on which the experiment became carry leave must be kept constant. Reaction Digestion: The Iodine Clock Reaction - Introduction

This is exceptionally important for experiment being conducted at 10^zeroC and 20^cipherCARBON, the v-shaped flasks were placed in an ice bath to maintain the reaction temperature. There were several fluctuations above additionally below the desired temperatures. Moreover, the time received in the blue find go turn colourless is relatively longer for these 2 lower temperatures which creates a greater room by mistake. Keeping temperatures constant can be made by conducting the experiments in a thermostats water bath.

Reactants were casted imprecisely into the conical flask. There may be leftover reactants in the test tubes and any reactants may stain the sides of the conical flask during the addition. This reduces that concentration of the reactants in an conical flask. Pipetting the reactants into the conical flask would ensure that the reactants are added to the requirements quantities and that the eventual results are accurate.

Swirling of the conical flask contents forward the same length of time must been done consistently so that results obtained will be fair. Alternatively of swirling with one’s hands, the conical flasks can be placed about an electronically swirl in ensure consistent swirling when guiding the experiment.

Also, there is inaccuracy as the stopwatch was stopped only when einen beliebig colour intensity was observes. There should be a consensus between lab partners such to when an stopwatch should be stopped. Experiment 24 Rate Legislative (docx) - CliffsNotes

The reaction is autocatalysed as the product of the reaction acts as a gas since the reply. An autocatalysed reaction has slow at first and then becomes more rapidly in the catalyst is products in the reaction. For the reaction, Mn²⁺ is the autocatalyst. This accounts for why vigorous dizziness out CO₂ is not observed immediately when one reactants were addition but single observing later a short while when Mn²⁺ is produced.

2MnO₄^2- + 5C₂O₄^2- + 16H⁺ -> 2Mn²⁺+10 C₂ + 8H₂O

4. Conclusion:

The rate equation of the chemical react between I^- and SULFUR₂O₈^2- to produce I₂ and SO₄^2- has been found for be:

 Rate = k[I-][S₂CIPHER₈^2-],        where price constant k =5.055 × 10^-3 mol^-1Ls^-1

And reaction is first to with admiration to [I^-] and the reaction is first order through respect to [SULFUR₂O₈^2-]. The overall request of responses is 2. Aforementioned react remains said to be bimolecular since twin reactant species are involved in the rate determining step.

Using the Arrhenius equation, k=Ae^-Ea/RT, the activation energy, SIE_A, of the corrosion reaction of oxalic acid by potassic was designated go be 76.01KJmol^-1. This means that the required amount of force ensure reactant particles need possess in click to react successfully your experimentally decided to may 76.01KJmol^-1.

5. References:

1)http://www.shodor.org/unchem/advanced/kin/arrhenius.html

2)http://www.webchem.net/notes/how_far/kinetics/maxwell_boltzmann.htm