• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13
  14. 14
    14
  15. 15
    15
  16. 16
    16
  17. 17
    17

Esterification Equilibrium

Extracts from this document...

Introduction

IB Group 4 Internal Assessment Chemistry Biology Physics Name: Date(s): Candidate Number: Session: Level: Investigation Title: Internal Assessment Marking Form Criterion Required Aspects Level Complete (2) Partial (1) Not at All (0) Data Collection and Processing Records appropriate quantitative and associated qualitative raw data, including units and uncertainties where relevant. Records appropriate quantitative and associated qualitative raw data, but with some mistakes or omissions. Does not record any appropriate quantitative raw data or raw data is incomprehensible. 2 1 0 Aspect 1 - Recording Raw Data Aspect 2 - Processing Raw Data Processes the quantitative raw data correctly. Processes quantitative raw data, but with some mistakes and / or omissions. No processing of quantitative raw data is carried out or major mistakes are made in processing. 2 1 0 Aspect 3 - Presenting Raw Data Presents processed data appropriately and, where relevant, includes errors and uncertainties. Presents processed data appropriately, but with some mistakes and / or omissions. Presents processed data inappropriately or incomprehensibly. 2 1 0 Conclusion and Evaluation States a conclusion, with justification, based on a reasonable interpretation of the data. States a conclusion based on a reasonable interpretation of the data. States no conclusion or the conclusion is based on an unreasonable interpretation of the data. 2 1 0 Aspect 1 - Concluding Aspect 2 - Evaluating Procedure(s) Evaluates weaknesses and limitations. Identifies some weaknesses and limitations, but the evaluation is weak or missing. Identifies irrelevant weaknesses and limitations. 2 1 0 Aspect 3 - Improving the Investigation Suggests realistic improvements in respect of identified weaknesses and limitations. Suggests only superficial improvements. Suggests unrealistic improvements. 2 1 0 Introduction: The equilibrium constant could be calculated by using the formula. Where A + B -> C + D In determining the equilibrium constant for an esterification reaction, The equilibrium constant, KC , would be; The research question would be; determine the KC values for different mixtures. ...read more.

Middle

Mixture 1 contains 5ml of HCl and 5ml of ethyl ethanoate. There is no water present in this mixture; however, since HCl is in aqueous state, there is water present in the HCl solution. NaOH + HCl HCl -> H+ + Cl- C 0.9531M 3.2M => V 33.24x10-3 0.01 n 0.032 mols 0.032 mols 0.032 mols 0.032 mols 0.032 mols Hence, the amount of pure HCl could be calculated; Since there were 5ml of HCl solution in the mixture, then the amount of water could be calculated; Mixture 1 contained 5ml of ethyl ethanoate. To find the number of moles for ethyl ethanoate in equilibrium; NaOH + HX C 0.9531 V 44.65 n 0.043mol 33.24x10-3dm3 of NaOH was needed to react with 10ml of HCl, since in mixture 1 has 5ml of HCl, amount used of NaOH to react with HCl needs to be taken off from the overall amount of NaOH used for the mixture. Uncertainty Calculations Uncertainty = (0.9531�0) x (44.65x10-3�1.5x10-4) = 0.043�0.0034 Uncertainty Calculations Uncertainty = (44.65x10-3�1.5x10-4) - [(33.24x10-3�1.5x10-4)/2] = (44.65x10-3�1.5x10-4) - (16.62x10-3�7.5x10-5) = 28.03x10-3�2.25x10-4 NaOH + HX C 0.9531 3.20 V 28.03 x 10-3 0.005 n 0.027mol 0.027mol Number of mols of ethanoic acid in equilibrium would be 0.027mol. Since initial is 0 mols and equilibrium is 0.027, the change is 0.027 mols. Moving onto water, as shown above, there is no water present in the mixture, but only in the HCl, which is 3.83ml. If 3.83ml is to be converted into moles, then the number of moles at initial state would be; Uncertainty Calculations Uncertainty = (0.9531�0)x(28.03x10-3�2.25x10-4) = 0.0027�2.17x10-5 Because the change is 0.0027�2.17x10-5 mols, the number of moles of water in equilibrium is; 0.212�0.0009mol - 0.0027�2.17x10-5 = 0.185�9.217x10-4 As the initial number of moles of ethyl ethanoate in equilibrium could be calculated; Because the change is 0.027mols, the number of moles of ethyl ethanoate in equilibrium is; 0.052�2.286x10-4 - 0.027�2.17x10-5 = 0.025�2.50x10-4 mols. ...read more.

Conclusion

Improvements: Table 11. Lists of Improvements Experiments Effects Improvements Overshooting the end point By overshooting NaOH to the flask, the end point will be affected Calculate the end point of the titration and then perform titration, or carry out a rough titration and then perform a proper titration afterwards Subjectivity of the colour change Different people have different views on colour change Allow only one person to state whether if there was colour change or not. Also, to help the clear view of the colour change, place a blank white page behind the flask Use of different burettes to make the mixture By using different burettes to make the mixture, the uncertainty of the equipment will pile up Since there is no way of not using separate equipments to make the mixture, equipments with smaller uncertainty increments could be used Number of trials performed Due to lack of time, there was only one trial been performed Extend the number of trials and by cutting out the outliers, the uncertainty of each titrations Concentration of NaOH NaOH was made by the lab technicians. Therefore uncertainty of the concentration will exist, however, there was no mention about the uncertainty of NaOH Ask the lab technicians about the uncertainty of the NaOH Refilling the burette Some of the titrations for the mixtures exceeded 50mls; hence the burette had to be refilled. Due to this, the uncertainty doubled. Use a burette that can contain more than 50ml of the solution The time allowed to reach the equilibrium The mixture was left for one week in room temperature for it to reach equilibrium. Since it takes one week roughly, hence some of the mixture may not have reached equilibrium. Leave the mixture for around two weeks in room temperature for it to fully reach equilibrium Possibility of the equilibrium to shift during the titration due to room temperature The room temperature has to be set in 298K. However, due to air conditioner, the room temperature may have changed. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Chemistry essays

  1. IB chemistry revision notes

    o Breaking bonds: * Total --> 2640 kJ Making bonds: * Total --> -3338 kJ o These calculations can be unreliable as the products and reactants have to be in the gas phase. They don't take into account any energy changes associated with changes of state in either products or reactants.

  2. Acids/Bases Design Lab. How does a change in the pH value of a solution ...

    The water was then decanted from the 500cm3 beaker into a waste beaker. 13. The beaker, labeled CRT1, containing the recently rinsed zinc metal strip that reacted with the hydrochloric acid solution for one minute, was then placed on a hot plate set to low heat, and allowed to dry off for 5 minutes.

  1. Hydrogen Gas Collection Lab CE (6/6) A sample of solid magnesium ribbon, measuring approximately ...

    liquid that have attached themselves to the side of the gas measuring tube. Again, great care should be taken in ensuring the lip of the gas measuring tube does not breach the surface of the water, and that the tap water bath inside the 1000cm3 graduated cylinder is not too

  2. Aim. To find the identity of X(OH)2 (a group II metal hydroxide) by determining ...

    Dependant Variable: Is the volume of HCl to achieve a colour change that is from pink to colourless. The Controlled variables : 1. the same source of HCl 2. same concentration of HCl 3. Same source of X(OH)2 4. Same volume of X(OH)2 5.

  1. Titration of Na2CO3.xH2O with HCl

    Performing titration repetitions is the only way this error could be reduced. Therefore, after completing the process of titration, obtaining sufficient results and making the correct calculations, the number of moles of the water of crystallization of Na2CO3 was found to be (10.1 � 0.01)

  2. Measuring the fatty acid percentage of the reused sunflower oil after numerous times of ...

    As a result trans- unsaturated oils have high melting points. And the higher melting point increases the number of frying that can be made by using trans-oils. So it can be seen that another property apart from taste and cheapness is being reusable.

  1. Chemistry Titration Acid Base Lab

    In the lab, phenolphthalein required 0.90 mol/L of the sodium hydroxide solution in order for a color change to take place (endpoint was reached). This value is fairly close the concentration of acetic acid in the vinegar used in the lab, therefore, phenolphthalein was the most accurate of indicators used in this titration lab.

  2. The chemistry of atmospheric and water pollution.

    Point 4.11 ? Analyse the information available that indicates changes in atmospheric ozone concentrations describe the changes observed and explain how this information was obtained. The concentrations of ozone in the atmosphere have been recorded since 1957. In the 1970?s, it was found that CFCs were depleting the ozone layer in the stratosphere.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work