Chemistry Titration Lab

T adequate to(p) 1 entropy Collection Table Contains all of the ancient data directly obtained from the testing ground. Indicator initial record book of NaOH in burette (ml) 0. 05 utmost book of account of NaOH in burette (ml) 0. 05 final initial Burette Reading (Volume of NaOH utilize) (ml) 0. 1 Qualitative Observations Phenolphthalein 0. 00 0. 90 0. 9 At first when the bastardly was macrocosm dropped into the acetum there wasnt a garble mixture, as yet when the antecedents came close to full titration, the closure would turn tapdance and once conf utilise would turn clear again 0. 90 2. 30 1. 4 2. 30 3. 20 0. 9 3. 20 4. 0 0. 9 Bromothymol unsanctified 8. 00 9. 50 1. 5 termination saturnine from lily-live bolshy to light discolour 9. 50 11. 10 1. 6 resolving glowering from a bright sensationalistic to bright voluptuous rather than a light green indicating over-titration had occur personnel casualty 11. 10 12. 90 1. 8 12. 90 14. 40 1. 5 14. 40 15. 90 1. 5 methyl radical O epitome 15. 90 16. 90 1. 0 Reaction occurred quick, over-titration occurred and resolving turned from red to orange 16. 90 17. 20 0. 3 17. 20 17. 40 0. 2 17. 40 17. 60 0. 2 17. 60 17. 80 0. 2 methyl radical Red 0. 00 5. 00 5. 0 5. 00 7. 80 2. Solution turned from red to a light orange/yellow vividness 7. 80 10. 70 2. 9 10. 70 13. 60 2. 9 13. 60 16. 50 2. 9 Bromocresol Green 20. 80 21. 20 0. 4 Solution turned from yellow to light green 21. 20 21. 60 0. 4 21. 60 22. 00 0. 4 Table 2 Data touch Table displaying the tawdriness of NaOH requisite to titrate 10ml of acetum and their corresponding concentration of acetic acrimonious Indicator Volume of NaOH necessitate to titrate 10mL of Vinegar (ml) (0. 1) Concentration of acetic Acid 0. 5 (mol/l) portion uncertainness (%) Percent Error (%) Phenolphthalein 0. 0. 9mol/dm3 11. 1 3. 4 Bromothymol Blue 1. 5 1. 5mol/dm3 6. 7 72. 0 methyl group Orange 0. 2 0. 2mol/dm 3 50. 0 -77. 0 Methyl Red 2. 9 2. 9mol/dm3 3. 5 233. 0 Bromocresol Green 0. 4 0. 4mol/dm3 25. 0 -54. 0 Sample Calculations Ex. The deliberation of the concentration of acetic acid for phenolphthalein NaOH Volume 0. 9ml NaOH Concentration 1. 00mol/dm3 1. Convert Volume to Litres 0. 9 = 0. 0009L 1000 1. steer the moles of NaOH (n=CV) n= (1. 00mol/dm3) (0. 0009L) = 0. 0009mol 2. visualize the concentration of the thin acetic acid.Because acetic acid and sodium hydrated oxide save a 11 ratio, they slang the resembling number of moles. C = 0. 0009mol = 0. 09 0. 01L 3. Calculate the initial concentration of acetic acid pre-dilution C1V1 = C2V2 C1(0. 01L) = (0. 09mol/L)(0. 1) Concentration of Acetic Acid = 0. 9mol/L Sample Calculations Continued 4. Calculating pct uncertainty = absolute uncertainty x 100 Measurement 1 showcase Calculating the percent uncertainty for the deal of NaOH unavoidable when methyl red is employ = 0. 1 x 100 2. 9 1 = 3. 5% Therefore, the mass of NaOH inevitable when methyl red is used as the power is 2. 9ml 3. % 5. Uncertainty propagation for the peck of NaOH essential for each exp hotshotnt (0. 9 0. 1) + (1. 5 0. 1) + (0. 2 0. 1) + (2. 9 0. 1) + (0. 4 0. 1) = 5. 9ml 0. 5 6. Calculating percent flaw Percent actus reus = Actual pass judgment x 100 accepted display case Calculating percent computer fracture for phenolphthalein Percent phantasm = 0. 9 0. 87 x 100 0. 87 = 3. 4% Methyl Red Methyl Red Bromothymol Blue Bromothymol Blue Bromocresol Green Bromocresol Green Methyl Orange Methyl Orange Phenolphthalein Phenolphthalein interpret 1 Titration curve representing the doing of the book of account of NaOH on the pH of the titration resolvent at expiry loony toonsConclusion This research research science testing groundoratoryoratoryoratory tested the effect of the use of different indicators on the volume of NaOH required to slip by the finis post of the titration with acetic acid in vinegar. The eq uivalence for this reception is CH3COOH(aq) + NaOH(aq) NaCH3COO(aq) + H2O(l) The As single john correspond from graph 1 the allows of this lab demonstrated that the indicators that required different volumes of sodium hydroxide to moot abrogate transmit from least center of volume required to most was with the use of methyl orange, bromocresol green, phenolphthalein, bromothymol blue and get vently methyl red.Therefore, the highest volume of NaOH that was required to diversity the affectation of the vinegar occurred when utilise methyl red, and the smallest volume of NaOH that was required to sort the color of the vinegar occurred when use methyl orange. Different indicators were tested as if the indicator is chosen well, indeed(prenominal) the deathpoint go forth represent the equivalence point of the titration response the point when the volume of titrant is equal to the amount of analyte (the acetic acid in the vinegar). An primary(prenominal) factor to con placementr is hat indicators wearyt change color at a peculiar(prenominal) pH.However, they do change color over a take range of pH value. Because vinegar has a pH of near 2. 4 the symmetricalness was firmly to the go away before the sodium hydroxide was added. Adding the sodium hydroxide allow for begin to shift the residuum to the right. As to a greater extent and more alkali was added, for pillowcase with phenolphthalein, the rap eventually became so preponderating that it could no longer be turned clear by swirling the beaker. If the light pink was achieved, then terminate point was absolutely obtained and if the final result became bright pink then over-titration occurred.Although the majority of this lab occurred according to plan, there were a few minor inconclusive results that occurred. For instance, the amount of NaOH used in the titration when the methyl red indicator was used was 2. 9ml. However, for star of these tests when employ methyl red, the vo lume of NaOH required to get the terminate point of the reaction was 5. 0ml. This was a clear anomalous result as it was very different from the ordered 2. 9ml of NaOH from the other trials. This anomalous result laughingstock be explained due to several dictatorial and/or random that will be discussed further on with their potential amendments.There were no error bars included in this lab. This is due to the fact that they would be non-existent as each titration was repeated until the exact selfsame(prenominal) volume of NaOH was required to reach the end point for each different indicator at least 3 beats. general anatomy 1 Representation of the various indicators used passim the conductivity of this lab and their pH levels. It also demonstrates their modify in acids and colors in bases as well as the color when end point is reached. This lab evidently demonstrated that phenolphthalein would be the ruff indicator to use.The justification for this is that both indicator has their own individual range of pH for the end points. When the end point occurs, it style there is slightly excess base. For phenolphthalein, the end point would be when the color of the solution changed into a very light pink color. As one plenty see from figure 2 the indicator phenolphthalein altogether changes color in basic solutions. This is a reason why it would be considered the dress hat indicator for this experiment. This is because the end point for this experiment ranges in between a pH of 8. 2 and 10. , which as one faecal matter see is very similar to the pH ranges of phenolphthalein. This would cause the phenolphthalein to give the most full-strength reading of the volume of NaOH required to reach the end point of its reaction with acetic acid. The reason the other indicators may not give the most accurate readings tidy sum be seen from the diagram below chart 2 This graph represents a elementary visual of the effect of different indicators on the volume of base required to reach end point with an acid. The green hold on above represents the phenolphthalein in this lab as it has its pH ranges on the break of the curve.This elbow mode that the color change will be accurate in terms of ever-changing color at the break point of the reaction Evaluation There argon a variety of tracks this lab could be furthered. This lab was done using a strong base (NaOH) and a weak acid (acetic acid). A way that this lab could be furthered would be to do the exact same lab using a weak base and a strong acid such as NH4OH (ammonium hydroxide which is a weak base) the same weak acid (acetic acid). This would skew the results in that a untold higher volume of base would be required to reach end point with the acid. This is because it would be oftentimes more difficult to shift equilibrium o the right. For modelling, the phenolphthalein indicator only turns the solution pink in basic solutions. Because a weak base is what will be used, it would ta ke much more base in order to reach end point of the reaction. There were a few errors that could require been amend throughout the conduction of this lab. One of the major errors occurred prior to the positive titration itself. This error occurred when the sodium hydroxide solution was being created. When the sodium hydroxide was being created, 1g of solid sodium hydroxide pel permits had to be weighed using an electronic balance and then put in a volumetricalal flask.After this water was added to the sodium hydroxide pellets and diluted to the 150ml mark. The pellets were left in a bidding in the open while we were getting other materials set up. This was definitely an error as the sodium hydroxide pellets puff moisture from the air. This means that the sodium hydroxide was actually becoming heavier than 1g as it began entrancing his moisture. This stirred results as there was a higher concentration of sodium hydroxide in the water than recorded. This could brace affecte d the results in that less sodium hydroxide would film been required to reach the end point of the reaction.This would be considered a taxonomical error as the slightly increase mass of the NaOH would mystify been used for every trial as the same consultation of NaOH was used throughout. An improvement to this error would be to not put the sodium hydroxide pellets into the volumetric flask until the very last second. Also, the sodium hydroxide was put into the volumetric flask and then the water was added, however adding the water first could minimize the time that the solid sodium hydroxide is left in the air.This step in the functioning could also be modify if it were realizable to purchase this solid sodium hydroxide already measured out in grams so that they would only be in the open for a matter of seconds as they were being transferred into the volumetric flask. A taxonomic error that occurred throughout the process of this lab was over-titration. Over titration is when too much of the base is added to the solution and the reaction passes end point. For example, the color that one would attempt to achieve when perfectly titrating using phenolphthalein is a light pink color.However, for all of our trials the solution turned a bright fuchsia color when using phenolphthalein implying it had over-titrated. This error could definitely have been improved. The improvement for this error would be to use a burette with a smaller outset. This would allow fall room for the error of over-titration. This is because one would have more control over the volume of base released by the burette allowing for more control. Another systematic error that occurred repeatedly throughout the conduction of this lab was that the temperature of the room did not stay constant.Therefore, the temperature of the solutions including the indicators was not constant. Temperature changes could have occurred in the lab without being noted. This is a problem as it slightly changes the color change pH range of indicators. As one can see below, these be the effects on various normal indicators color change ranges with an increase in temperature Table 3 Table representing greenness indicators and the effect of changing temperature drastically on the color change range. Although the temperature would not have fluctuated drastically in the classroom there were still potential fluctuations that were not accounted for.This would have caused the end point to come along to be occurring at different times than evaluate for that indicator. The way this error could be improved would be to conduct the lab in an range where the temperature is closely and easily monitored. Conducting this lab in a classroom with the admittance frequently opening and shutting let in a draft therefore this lab should be conducted in an area with no interruptions that may effect temperature. Also, temperature can be monitored so that it can be at least accounted for in ones results and the changes in temperature can be used as an explanation for the behavior of the indicators in each test.Another section of the modus operandi of this lab that requires improvement relates to the indicators used. The indicators used throughout the process of this lab had pH ranges of around 2-3 increments. For example, phenolphthalein changes color over a pH range of around 8-10. This means that one would not be able to divide exactly what pH the final solution was when it reached end point from the indicator. This could be improved if indicators were produced that did not have a range of pH values in which they change color but one limited pH range where it changes the color of the solution.This would improve the lab as it would allow scientists to get exactly at which pH the end point of the reaction was reached exactly when it happens. For example, this specific experiment is supposed to reach end point between pH values 8-10, however having an indicator that changes color a t pH 8, one that changes color at pH 9 and one at 10 would allow for a more accurate result. An additional random error that occurred throughout the process of this lab was that seldom a drop of NaOH wouldnt aim out of the burette completely straight and would end up getting stuck to the side of the beaker.This would have caused the volume of NaOH required to reach end point of the reaction to appear greater than it actually was. This is because NaOH was leaving the burette but not going into the beaker containing the vinegar and indicator. Although one cannot control the behaviour of the burette with the NaOH other than potentially using a burette with a thinner opening allowing for less room for the NaOH to fall from gloomy angles, one can control beaker size.By increase the size of the beaker containing the vinegar and the indicator, one is able to reduce the likelihood of the NaOH not going directly into that beaker. This would mean that there wouldnt be as much NaOH mixed-up from the burette that isnt accounted for. Often in the real world, titration experiments are performed regularly. This is because titration is a process of determining the concentration of a join in an un cognise solution, in which a known reagent is added to that unknown solution in order to produce a known reaction such as a color change.A real world example of this is biodiesel labor. Acid-base titrations are used in the production of biodiesel in order to determine the sullenness of waste vegetable oil (one of the important ingredients in biodiesel production). pH paper is used to test a small warning in order to represent the pH of the entire batch. This allows one to determine how much base is required to achieve the in demand(p) pH. Bibliography Websites Chemical Analysis by Acid-Base Titration. AcidBaseTitration. N. p. , n. d. Web. 12 Nov. 2012. <http//chem. lapeer. org/Chem2Docs/AcidBaseTitration. html>. ChemTeacher. ChemTeacher. N. p. , n. d. Web. 12 Nov. 2012. <http//chemteacher. chemeddl. org/services/chemteacher/index. php? natural selection =com_content>. Sample laboratory Report. Sample testing ground Report. N. p. , n. d. Web. 12 Nov. 2012. <http//www. chem. purdue. edu/courses/chm115/Laboratory/Records___Reports/Sample_Lab_Report/sample_lab_report. html>. Titration Lab Report. Titration Lab Report. N. p. , n. d. Web. 12 Nov. 2012. <http//www. slideshare. net/AuburnFeather/cfakepathtitration-of-7>. Books textbook Talbot, Chris. Chemistry for the IB Diploma. London Hodder Murray, 2009. Print.