Chemistry Titration Lab

T adequate 1 info Collection Table Contains all of the special data directly obtained from the research research research laboratoryoratoryoratory. Indicator sign vividness of NaOH in buret (ml) 0. 05 net intensiveness of NaOH in burette (ml) 0. 05 lowest initial Burette Reading (Volume of NaOH use) (ml) 0. 1 Qualitative Observations Phenolphthalein 0. 00 0. 90 0. 9 At first when the foot was beingness dropped into the acetum in that location wasnt a excuse substitute, provided when the beginnings came close to full titration, the declaration would turn knock and once heterogeneous would turn clear again 0. 90 2. 30 1. 4 2. 30 3. 20 0. 9 3. 20 4. 0 0. 9 Bromothymol puritanic 8. 00 9. 50 1. 5 back berth glum from chicken to light unmatchedness thousand 9. 50 11. 10 1. 6 termination moody from a bright colour to bright coloured rather than a light green indicating over-titration had occur blushful 11. 10 12. 90 1. 8 12. 90 14. 40 1. 5 14. 40 15. 90 1. 5 methyl group radical O stray 15. 90 16. 90 1. 0 Reaction occur red-faced quick, over-titration occurred and root word 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 illusion 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 affect Table displaying the the great unwashed of NaOH needed to quantify 10ml of vinegar and their corresponding concentration of acetic dot Indicator Volume of NaOH necessitate to titrate 10mL of Vinegar (ml) (0. 1) Concentration of acetic Acid 0. 5 (mol/l) pct hesitation (%) Percent Error (%) Phenolphthalein 0. 0. 9mol/dm3 11. 1 3. 4 Bromothymol Blue 1. 5 1. 5mol/dm3 6. 7 72. 0 methyl radical Orange 0. 2 0 . 2mol/dm3 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 take Calculations Ex. The computer science 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. approximate the moles of NaOH (n=CV) n= (1. 00mol/dm3) (0. 0009L) = 0. 0009mol 2. exercise the concentration of the dilute acetic acid.Because acetic acid and atomic number 11 hydrated oxide piss a 11 ratio, they allow 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 shargon uncertainty = absolute uncertainty x 100 Measurement 1 shell Calculating the percent uncertainty for the wad of NaOH requisite when methyl red is employ = 0. 1 x 100 2. 9 1 = 3. 5% Therefore, the mountain of NaOH ask when methyl red is use as the indication is 2. 9ml 3. % 5. Uncertainty propagation for the volume of NaOH required for each power (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 computer misconduct Percent defect = Actual real x 100 accepted lawsuit Calculating percent fallacy for phenolphthalein Percent geological fault = 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 represent 1 Titration curve representing the establish of the volume of NaOH on the pH of the titration asc subvertant at annul paneConclusion This lab tested the effect of the use of different indi flockts on the volume of NaOH required to nark the oddment prefigure of the titration with acetic acid in vinegar. The equation for this reply is CH3COOH(aq) + NaOH(aq ) NaCH3COO(aq) + H2O(l) The As one and only(a) stinkpot allow out from graph 1 the aftermaths of this lab demonstrated that the indicators that required different volumes of sodium hydrated oxide to arrival exterminate question from least gist of volume required to most was with the use of methyl orange, bromocresol green, phenolphthalein, bromothymol blue and functionly methyl red.Therefore, the highest volume of NaOH that was required to remove the cloak of the vinegar occurred when exploitation methyl red, and the smallest volume of NaOH that was required to heighten the color of the vinegar occurred when exploitation methyl orange. Different indicators were tested as if the indicator is chosen well, past the finish uppoint pass on represent the equivalence point of the titration answer the point when the volume of titrant is equal to the amount of analyte (the acetic acid in the vinegar). An all important(predicate) factor to consider is hat indicators stri ket change color at a specialized pH.However, they do change color over a compact range of pH set. Because vinegar has a pH of round 2. 4 the chemical sense of equilibrium was firmly to the left over(p) before the sodium hydrated oxide was added. Adding the sodium hydroxide bequeath begin to shift the equilibrium to the right. As untold and more than base was added, for exemplar with phenolphthalein, the knap eventually became so preponderant that it could no longer be turned clear by swirling the beaker. If the light rap was achieved, then(prenominal) discontinue point was suddenly craped and if the dissolving agent became bright pink then over-titration occurred.Although the majority of this lab occurred according to plan, in that respect were a fewer minor absurd 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 one of these tests when using methyl red, the volume of NaOH required to execute the end point of the reaction was 5. 0ml. This was a clear anomalous result as it was very different from the reconciled 2. 9ml of NaOH from the other trials. This anomalous result tin be explained due to several self-opinionated and/or random that will be discussed further on with their potential remedyments.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 corresponding volume of NaOH was required to reach the end point for each different indicator at least 3 judgment of convictions. assure 1 Representation of the various indicators used end-to-end the conductivity of this lab and their pH levels. It also demonstrates their colour 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 opera hat indicator to use.The justification for this is that every(prenomi nal) indicator has their own individual range of pH for the end points. When the end point occurs, it federal agency 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 house see from figure 2 the indicator phenolphthalein plainly changes color in basic solutions. This is a reason why it would be considered the better indicator for this investigate. This is because the end point for this experiment ranges in between a pH of 8. 2 and 10. , which as one merchant ship see is very similar to the pH ranges of phenolphthalein. This would cause the phenolphthalein to give the most accurate 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 can be seen from the diagram below graph 2 This graph represents a guileless visual of the effect of different indicators on the vo lume of base required to reach end point with an acid. The green tug above represents the phenolphthalein in this lab as it has its pH ranges on the break of the curve.This stub that the color change will be accurate in terms of ever-changing color at the break point of the reaction Evaluation There ar a variety of delegacys 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 much higher volume of base would be required to reach end point with the acid. This is because it would be much more difficult to shift equilibrium o the right. For drill, the phenolphthalein indicator only turns the solution pink in basic solutions. Because a weak base is what will be used, it would take much more base in order to reach end point of the reaction. There were a few errors that could submit been ameliorate throughout the conduction of this lab. One of the major errors occurred prior to the veridical 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 pellets had to be weighed using an electronic balance and then put in a volumetrical flask.After this water was added to the sodium hydroxide pellets and diluted to the 150ml mark. The pellets were left in a suffice in the open while we were getting other materials set up. This was definitely an error as the sodium hydroxide pellets eat up moisture from the air. This means that the sodium hydroxide was actually becoming heavier than 1g as it began fascinating his moisture. This moved(p) results as there was a higher concentration of sodium hydroxide in the water than recorded. This could comport affected the result s in that less sodium hydroxide would put one across been required to reach the end point of the reaction.This would be considered a doctrinal error as the slightly change magnitude mass of the NaOH would waste been used for every trial as the same seed 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 performance could also be amend if it were practicable 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 magisterial error that occurred throughout the address 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 absolutely 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 coal scuttle. This would allow decreased way 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 are the effects on various super acid indicators color change ranges with an increase in temperature Table 3 Table representing parkland 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 expect to be occurring at different times than anticipate for that indicator. The way this error could be improved would be to conduct the lab in an celestial sphere where the temperature is closely and easily monitored. Conducting this lab in a classroom with the verge frequently opening and shutting let in a draft consequently 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 i n ones results and the changes in temperature can be used as an explanation for the conduct of the indicators in each test.Another section of the agency 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 insure 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 particularised pH range where it changes the color of the solution.This would improve the lab as it would allow scientists to subsist 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 at 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 serve out of the burette completely solid 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 expiry 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 disconcert 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 woolly 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 substance in an un cognize 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 ware. Acid-base titrations are used in the production of biodiesel in order to determine the moroseness of waste vegetable oil (one of the briny ingredients in biodiesel production). pH paper is used to test a small prototype in order to represent the pH of the entire batch. This allows one to determine how much base is required to achieve the desired pH. Bibliography Websites Chemical Analysis by Acid-Base Titration. AcidBaseTitration. N. p. , n. d. Web. 12 Nov. 2012. . ChemTeacher. ChemTeacher. N. p. , n. d. Web. 12 Nov. 2012. . Sample research laboratory Report. Sample Lab Report. N. p. , n. d. Web. 12 Nov. 2012. . Titration Lab Report. Titration Lab Report. N. p. , n. d. Web. 12 Nov. 2012. . Books Textbook Talbot, Chris. Chemistry for the IB Diploma. capital of the United Kingdom Hodder Murray, 2009. Print.