At the beginning, the aim of this experiment is to size up the rate of reaction and the output transition. And the foremost principal that should be applied in order to find both rate of reaction and output transition is material balance for batch reactions. As the experiment travel on, pupils are supposed to comprehend the factors providing the output, rate of reaction and besides the transition. Harmonizing to the hypothesis of the experiment, with the increase of ethyl ethanoate ( reactant ) from 0.1M to 0.2M the rate of reaction should bit by bit increase, taking to an augmentation of the rate of reaction every bit good as the transition of Na ethanoate from Na hydrated oxide.
Second, the theories that pupils must be acquainted with is, batch reaction, transition, rate of reaction, conduction output and saponification. Saponification is an indispensable theory that drive the whole experiment, as it map by hydrolysing an ester, organizing a acidic salt and intoxicant. With the absence of the pertinent cognition of saponification, the experiment will non be successful.
Third, the modus operandi of the experiment, it comprises of 3 focal stairss, readying of reactant, experimental agreement and process to be carried out during experiment. Students are to be peculiarly argus-eyed during the experiment, as reactant given, incorporate some parlous substances that are damaging to human organic structure.
Subsequently, with the usage of two different concentration of acetyl ethanoate during the experiment, the consequence and computation of output and rate of reaction could be analyzed. The consequence tabularize based on the two different concentration should demo a huge divergency. The 0.2M of ethyl ethanoate should possess a higher output and rate of reaction harmonizing to the hypothesis of the experiment.
Before continuing to the decision, pupils are supposed to travel through some treatment on the experiment. The points to be discussed are viz. preventive step and the factors impacting the rate of reaction.
As a concluding point, the decision, it concludes whether the hypothesis of the experiment corresponds with the existent experiment performed. Tentatively the decision should back up the hypothesis of the experiment, which is, as the concentration of ethyl ethanoate additions, the rate of reaction and transition besides increases. ( Singapore Polytechnic 2009 )
Material balance with chemical reaction
1. Introduction
1.1 Background
Over the old ages, tonss of researches have been done to capitalise on the output, transition and increase the rate of reaction. These three factors are the point in which have close connexion with the net income of the company. By increasing the output it means more production generate with a standard sum of reactant used. As for rate of reaction, rationally, the faster the rate of reaction the greater the production rate within a certain period. During the experiment, batch procedure is employed as a medium for chemical reaction between Na hydrated oxide and ethyl ethanoate to take topographic point. The reaction produces sodium ethanoate and ethyl alcohol every 30 proceedingss, recording was taken every one proceedingss to observe down the conduction values. The whole procedure of obtaining the merchandise from sodium hydrated oxide and ethyl ethanoate, consist of batch procedure, closed system, jurisprudence of transition and besides saponification reaction.
Batch procedure, is a procedure when a fixed charge of natural stuff is introduced and the merchandises withdrawn before the rhythm repetition. A closed system is a system where no stuff crosses the system boundary. As for The Law of Conservation of Energy it states that energy can non be created or destroyed, but can alter its signifier. Last For unsteady province procedure, it means, non all of the conditions in the procedure remain changeless with clip or the flows in and out of the system can change with clip.
1.2 Aim
The purpose of this experiment on material balance with chemical reaction is to let pupils to use the rule of material balance with chemical reaction for batch reaction by finding the output, transition and reaction rate. The intent is to let pupils to understand the alteration of reaction, when the concentrated NaoH react with ethyl ethanoate in a reactor as clip base on ballss by. With the cognition of it, we will so be able to understand the saponification reaction of NaoH with ethyl acetate solution.
1.3 Hypothesis
The hypothesis of the experiment is that during the Saponification reaction between NaOH and Ethyl acetate solution in the reactor, the concentration of NaOH would diminish due to the figure of NaOH molecules being used for the reaction to bring forth sodium ethanoate. Furthermore, by increasing the concentration of ethyl ethanoate, the rate of reaction will besides be increased
2. Theory
2.1 Introduction of Theory
The function of the theory below is to give a more elaborate accounts on saponification, batch procedure, transition, output, rate of reaction and conduction, so that is can let pupils to hold a better perceptual experience on the experiment.
2.2 Batch Procedure
Batch procedure is a procedure in which a fixed charge of natural stuff is introduced and the merchandise is withdrawn before the rhythm repetition. During the experiment, batch procedure is employed, as reactants are put in to the system for 30 proceedingss for reaction to take topographic point. After which merchandises are withdrawn and the setup used are sluice before another batch of reactant are introduced once more. Owing to the alteration in concentration and production of new merchandise, the reaction is classs under unsteady province. ( Singapore Polytechnic 2009 )
2.3 Saponification
Saponification is defined as a procedure where ester is hydrolyzed, organizing an acid salt and an intoxicant. For this experiment, pupils are suppose to use the cognition they acquired on saponification and respond ethyl ethanoate and Na hydrated oxide and to bring forth sodium ethanoate and ethyl alcohol as the merchandise of the reaction. Sodium ethanoate is form due to the supplanting reaction which occurred during the overall reaction. The H in ester is displaced by the Na ion in the Na hydrated oxide, therefore organizing an acerb salt ; Na ethanoate. The reaction is irreversible, therefore once the merchandise is formed, it can non be re reacted to organize the initial province of Na hydrated oxide and ethyl ethanoate. However, reaction could be accelerated with the usage of a strong acid ( concentrated sulfuric acid ) as the accelerator of the reaction. ( Richard Hamner, Green Mountain Soap Company 2006 )
2.4 Conversion
Conversion is a technique, when a provender is converted to merchandises. The term transition can besides be defined mathematically as per centum transition. Percentage transition is derived by spliting ; moles of cardinal reactant that react, with mole of provender introduced and multiply it with 100 % . A 100 % transition is non likely to happen in the lab, this is due to the restrain of mechanism, which deprived the ideal transition to transpirate. ( Singapore Polytechnic 2009 )
2.5 Output
There are voluminous definitions for output. The three by and large prevailing definitions are yield based on provender, output based on the reactant consumed and in conclusion yield based on the theoretical ingestion of the modification reactant. These three definitions are normally employed by chemical technology industrial to guesstimate the output of the merchandises. Output based on provender are exemplify to be ; sum of coveted merchandise obtained, divided by sum of cardinal reactant ( restricting reactant Federal ) . As for output based on the reactant consumed, it is depict as ; sum of coveted merchandises obtained, divided by sum of the cardinal reactant consumed. Last as for output based on the theoretical ingestion of the modification reactant ; it is elucidate as ; sum of merchandise obtained, divided by the theoretical sum of merchandises that would be obtained based on the modification reactant if restricting reactant react wholly. The use of the expression varies from the given information. ( Singapore Polytechnic 2009 )
2.6 Rate of Reaction
Rate of reaction is the velocity of the overall reaction ; it can be affected by temperature, conduction, force per unit area, concentration surface country, and besides accelerator.
2.6.1 Temperature
Temperature will radically impact the rate of reaction. The hit of atoms is determined by the energy a atom possessed. With a higher temperature, it will provide the atoms to hold a higher energy, therefore increase the effectivity of hit, and finally ensuing to a faster rate of reaction ( Redspot Publishing 2005 ) .
2.6.2 Pressure
Pressure is defined as a status of being compress. The addition of force per unit area will provide to a faster rate of reaction as the countries the atom have are smaller after compaction. This therefore causes atom of be closely package together which consequence to a higher frequence of hit between gaseous molecules. However, the addition of force per unit area is merely applicable for gaseous molecules, as liquid and solid can non be compressed ( Redspot Publishing 2005 ) .
2.6.3 Concentration
Additions of concentration mean that the presences of atoms in a specific volume have increased. While the volume/ infinite remained changeless, the measure of the atoms additions, these instigate the frequence of hit to be higher, and besides heightening in the effectivity of hit. This consequence on atoms hit will promote a faster rate of reaction during the reaction ( Redspot Publishing 2005 ) .
2.6.4 Surface Area to Volume Ratio
The bigger the size of the atoms, the smaller the surface country for hit of atoms, whereas, when the atoms sizes are reduced, the opportunities of atoms clashing in to each other will be higher. This is due to the additions in surface country of atoms with it size are being cut down. Rate of reaction will therefore additions as frequence of hit increased ( Redspot Publishing 2005 ) .
2.6.5 Presence of Catalyst
Catalyst is defined as a substance that is capable of cut downing the activation energy of atoms without itself taking portion in the reaction. Therefore with the presence of a accelerator, atoms will hold a higher energy than the activation energy. These will take to a higher frequence of hit and besides the much more effectual hit. Rate of reaction will bit by bit increases with more hit taking topographic point ( Redspot Publishing 2005 ) .
2.7 Conduction
The conduction values of Na hydrated oxide is equivalent to the conduction values of the solution, as the conduction values of other reactants such as ethyl ethanoate, Na hydrated oxide and ethyl alcohol are inconsequential. With the conduction values of the solution ascertained, the concentration of Na hydrated oxide in the reacting mixture can so be determined. The rate on how fast concentration of Na hydrated oxide is consuming can that be easy achieved, by tabling a graph ( Copyright 2009 — Russell Mainstream Supply Ltd )
3. Procedure
3.1 Preparation of Get downing Reactant
Before get downing with the experiment, pupils should travel through and understand the Material Safety Data Sheet ( MSDS ) of Na hydrated oxide and ethyl ethanoate. The apprehension of the information sheet is imperative as, without apt apprehension on the chemical used, parlous jeopardy might happen. The process on handling and disposal of chemical must be habituated before the beginning of the experiment. Students are managing with extremely acidic concentrated reactant, hence, disposable baseball mitt and chemical goggles should be putted on at all clip during the experiment. 500mL of 0.01M of Na hydrated oxide solution and 500mL of 0.01M ethyl ethanoate was the concentration needed to be prepared for this experiment.
500mL of 0.01M Na hydrated oxide are suppose to be prepared, to make so, mensurating cylinder was used to mensurate the needed volume of 0.01M NaOH and poured in to a 500mL volumetric flask. De ionised H2O is poured in to the 500mL grade on the volumetric flask for dilution intents. To guarantee a all right dilution, flask should be covered with stopper and agitate to guarantee solution decently assorted.
Preparation of 500mL of ethyl acetate solution was done by pouring 250mL of de ionised H2O into a 500mL volumetric flask, followed by mensurating the stock solution utilizing a micropipettor and dispenses it to the 500mL volumetric flask. Exceed up solution up to 500mL grade, and cover it with a stopper and agitate the solution to guarantee solution is good assorted.
Experimental Setup
Figure 3.2.1 is the experimental apparatus. Permission should be granted before running the experiment.
Figure3.2. 1: Experimental apparatus
Conductivity metre
1-litre reaction beaker
Magnetic stirring device
Conductivity investigation
Reacting mixture
Retort base
Procedure During Experiment
As the readying of the Na hydroxide solution is completed, solution is poured in to the reactor with the reaction conditions adjusted to predetermined degree. The reaction conditions are straight related to the overall reactions ; hence the recording of the status is indispensable. Examples of the status are, temperature, stirring velocity, concentration and volume of reactions. Before the stirring procedure inaugurate, guarantee that the conduction metre investigation is positioned into the reacting mixture and a stop watch is ready for clocking intents. Ethyl ethanoate is to be poured in to the reactor, and entering should get down instantly. While the solution is being stirred in the reactors, conduction values are recorded at a regular interval of one minute for 30 proceedingss. After 30 proceedingss, reactor is stopped and a magnetic rod is used, to take the magnetic splash saloon in the reactor. The conduction investigation is so withdrawn and sluiced conscientiously with de ionised H2O. As for the merchandise, it is being disposed into a fictile waste container. The experiment is to be repeated based on the experimental methodological analysis discussed with lector. However, to guarantee consistence of the experiment, all glasswork is to be rinsed. Once all the experiment is accomplished, all the equipments should be decently cleaned and chemical used are to be disposed in to the fictile waste container. Finally waste will be send to W314 for proper intervention before flinging and glasswork used should be placed back to original location.
Consequence and Calculation
The tabular array shown below ( 4.1. and 4.1.2 ) shows the tabulated information of the values that were recorded during the experiment.
Consequences for reaction of NaOH with Ethyl ethanoate ( diluted from 0.49cm 3 )
Time ( min )
Conductivity value ( µS/cm )
Concentration of NaOH ( M )
Temperature ( 0C )
1
1013
0.0027
25.6
2
992
0.0026
25.6
3
970
0.00249
25.6
4
957
0.00241
25.6
5
933
0.00230
25.6
6
916
0.00222
25.6
7
902
0.00214
25.5
8
886
0.00206
25.5
9
874
0.00202
25.5
10
860
0.00192
25.5
11
848
0.00184
25.5
12
836
0.00177
25.5
13
825
0.00170
25.5
14
813
0.00163
25.4
15
803
0.00156
25.4
16
793
0.00139
25.4
17
783
0.00134
25.4
18
773
0.00131
25.4
19
765
0.00127
25.3
20
758
0.00124
25.3
( Table 4.1 )
Consequences for reaction of NaOH with Ethyl ethanoate ( diluted from 0.98cm 3 ) ( dual the concentration )
Time ( min )
Conductivity value ( µS )
Concentration Of NaOH ( M )
Temperature ( & A ; deg ; C )
1
1026
0.00278
24.9
2
1004
0.00267
25.1
3
988
0.00259
25.1
4
966
0.00248
25.1
5
950
0.00239
25.1
6
932
0.00231
25.1
7
914
0.00222
25.1
8
900
0.00215
25.1
9
889
0.00208
25.1
10
875
0.00201
25.1
11
863
0.00193
25.0
12
848
0.00184
25.0
13
837
0.00177
25.0
14
831
0.00175
24.9
15
824
0.00170
24.9
16
808
0.00157
25.0
17
797
0.00140
25.0
18
784
0.00134
25.0
19
781
0.00133
25.0
20
770
0.00131
25.0
( Table 4.1.2 )
4.2 Determination of the Output of Sodium Acetate
Determination of the output of Na ethanoate is associated with the concentration of Na hydrated oxide. In tandem with the given information on the concentration of Na hydrated oxide, the molar ratio employed can be dextrously deciphered. From here, computation to verify the output can be facilely obtained by utilizing the mole, which is calculated utilizing the molar ratio of Na hydrated oxide and ethyl ethanoate. Finally, use the expression of output computation and the finding of the output of Na ethanoate can be anatomized.
4.3 Output and Rate of Conversion of 0.01M Ethyl Acetate Solution for 15 Minutess.
Concentration of Na hydrated oxide at one minute interval
Time ( min )
Concentration of NaOH ( M )
1
0.0027
2
0.0026
3
0.00249
4
0.00241
5
0.00230
6
0.00222
7
0.00214
8
0.00206
9
0.00202
10
0.00192
11
0.00184
12
0.00177
13
0.00170
14
0.00163
15
0.00156
16
0.00139
17
0.00134
18
0.00131
19
0.00127
20
0.00124
( Table 4.3.1 )
Figure 4.3.2 Graph demoing concentration of sodium hydrated oxide against clip ( 0.01M of ethyl ethanoate used )
NaOH + CH3COOC2H5 & A ; agrave ; C2H5OH + CH3COONa
Theoretical Mole of NaOH = 0.01 X 0.5L = 0.005 mol
Actual Mole of NaOH = 0.00156 X 0.5L = 0.00078mol
Number of moles reacted = 0.005 – 0.00078 = 0.00422mol
Conversion of NaOH= 0.00422/0.005 X 100 %
= 84.4 %
Theoretically, since 1 mole of NaOH react and signifier 1 mole of CH3COONa, existent mole of CH3COONa= 0.00078
Output of CH3COONa= 0.00078/0.005
=0.156
4.4 Output and Rate of Conversion of 0.02M Ethyl Acetate Solution for 15 Minutess
Concentration of Na hydrated oxide at one minute interval
Time ( min )
Concentration Of NaOH ( M )
1
0.00278
2
0.00267
3
0.00259
4
0.00248
5
0.00239
6
0.00231
7
0.00222
8
0.00215
9
0.00208
10
0.00201
11
0.00193
12
0.00184
13
0.00177
14
0.00175
15
0.00170
16
0.00157
17
0.00140
18
0.00134
19
0.00133
20
0.00131
( Table 4.4.1 )
Figure 4.4.2. Graph demoing concentration of sodium hydrated oxide against clip ( 0.02M of ethyl ethanoate used )
NaOH + CH3COOC2H5 & A ; agrave ; C2H5OH + CH3COONa
Set 2
Theoretical mole of NaOH = 0.02 X 0.5L = 0.01 mol
Actual mole of NaOH = 0.0017 X 0.5L = 0.00085mol
Number of moles reacted = 0.01 – 0.00085 = 0.00915mol
Conversion of NaOH= 0.00915/0.01 X 100 %
= 91.5 %
Theoretically, since 1 mole of NaOH react and signifier 1 mole of CH3COONa, existent mole of CH3COONa= 0.00085
Output of CH3COONa= 0.00085/0.01
=0.085
4.5 Rate of Reaction of 0.01M of Ethyl Acetate
Graph 4.5.1. Shows the rate of reaction of Na hydrated oxide when 0.01M of ethyl ethanoate was added.
Graph shown above is consecutive line. Gradient= 0.00265-0.0012 & A ; divide ; 20 – 1 = 0.0000763 ( From the graph )
4.6 Rate of Reaction of 0.02M of Ethyl Acetate
Graph 4.6.1.Shows the rate of reaction of Na hydrated oxide when 0.02M of ethyl ethanoate was added.
Graph shown above is consecutive line.
Gradient= 0.00275 – 0.00125 & A ; divide ; 20 – 1 = 0.0000789 ( From the graph )
5. Discussion
5.1 Factors Affecting Rate of Reaction
As indicated above, there are legion factors that are capable of impacting the rate of reaction nevertheless ; the merely applicable one is the differences in concentration as the remainder ( temperature and force per unit area ) are kept changeless. Based on the experiment did, as the volume and concentration additions, the rate of reaction besides increases, this is by virtuousness of the presence of more atoms in the solution, therefore increasing the opportunities of atoms clashing to each other, which finally result in an addition in the rate of reaction.
Below is a graph to farther elaborate on the account on the difference in concentration.
( Graph5.1.1 )
The judgement on the rate of reaction is based on the abruptness of the graph. As shown, the black line which contains 0.02M of ethyl ethanoate has a slower rate of reaction as compared to the 1 in ruddy which is 0.01M of ethyl ethanoate. This repudiated the hypothesis of this experiment. The dialectics of this contradiction is, there might be beginning of contamination on setup or solution used.
5.2 Factors Affecting Conversion and Yield
The ideal rate of transition and output will ne’er be actualize under school environment or even in industries. As, in school pupils are utilizing oculus sight as a gage for the experiment which beyond doubt cause mistake due to parallax mistake, as for industries, despite being able to afford high cost machines and computing machine, the procrastination between human and machines will do an little differ on the rate of transition and output.
5.3 Factors Affecting Conductivity Values
As reference on the theory subdivision, the conduction values of ethyl ethanoate are unperceivable ; therefore the conduction rate of Na hydrated oxide is employed alternatively.
During the experiment, 2 different concentration of ethyl ethanoate was used. The first set of experiment, we used a concentration of 0.01M. It produces a changeless decreasing rate at every one minute interval. This shows that while the moles of Na hydrated oxide are consuming, conduction value to diminish excessively.
As for the 2nd set of experiment, the same things occurred but at a same rate as the first set of the experiment. This contravene the theory, as suppositionally, the additions in concentration to 0.02M will do the moles of Na hydrated oxide to consume at a faster rate, which result to a faster decreasing rate for conduction. Again, the dialectics of this contradiction is, there might be beginning of contamination on setup or solution used.
5.4 Precaution in Experiment
As we all know, ethyl ethanoate are really volatile, it release harmful gas when it is expose to the environments. Therefore, adding of ethyl ethanoate into the volume metric flask must be carried out in the smoke goon to forestall pupils from inhaling gases produced from ethyl ethanoate, which is harmful to human organic structure. In add-on, safety goggles and rubber baseball mitts should be worn at all times during the experiment. This aid to forestall pupils from holding direct contact with the acid which might do skin annoyance of impermanent loss of vision.
5.5 Comparison of Two Different Trials
As two different concentrations were employed during the experiments, the consequence on output and transition rate will be different.
5.5.1 Comparison of the Output of Two Different Trials
Upon completion of experiments, the differences in output were realised. The output of 0.01M ethyl ethanoate was 0.156 and the output of 0.02M ethyl ethanoate is 0.085. Theoretically, due to the increase in concentration, the output of 0.02M of ethyl ethanoate should be higher as, since more reactants is used ; it will truly ensue in more merchandises being formed. However, as reference above, there might be opportunities of the reactants or setup used being contaminated, which result in the immense differences between the outputs.
5.5.2 Comparison of the Conversion Rate
The transition rate of 0.01M of ethyl ethanoate was 84.4 % and the transition rate of 0.02M of ethyl ethanoate was 91.5 % . The consequence shown was first-class, as high transition rate will intend that, bulk of the reactant was to the full utilised, therefore salvaging cost.
6. Decision
Based on experiment, I can interpret that the higher the concentration of ethyl ethanoate, it will ensue to a much faster rate of reaction, and a higher rate of transition. The conduction value is interred related and proportioned to the concentration of Na hydrated oxide. Therefore, since observation and hypothesis are similar, the hypothesis is true.
The purpose of the experiment are besides fulfilled, as examination of the experiment have verify that, while the concentration of ethyl ethanoate got higher, the rate of reaction and rate of transition additions. In add-on, adding of accelerator or increasing encompassing temperature could besides ensue in a faster rate of reaction which tantamount to an increase in rate of transition.
