Fizzy drinks Essay

AimThe aim of the prove is to check whether pH of the chosen fizzy present is basic, neutral or acidic. To find the answer the titration method pull up stakes be used. The chosen fizzy drink go away be fag due to its transparency (it is easy to see when the color changes during the experiment).Hypothesis pansy will probably have acidic pH (smaller than 7) as one of ingredients is citric acid. However as it is drink used by people pH cannot be to small as it would be harmful to the human organism. As I checked pH of Sprite should oscillate somewhere around 2.75.TheoryA titration is a method of analysis that will allow you to determine the precise endpoint of a reaction and therefore the precise measuring stick of reactant in the titration flask. A buret is used to deliver the second reactant to the flask and an indicator or pH Meter is used to detect the endpoint of the reaction.A typical titration begins with a beaker or Erlenmeyer flask containing a precise volume of the reac tant and a small meat of indicator, placed underneath a burette containing the reagent. By controlling the amount of reagent added to the reactant, it is possible to detect the point at which the indicator changes colour. As long as the indicator has been chosen correctly, this should also be the point where the reactant and reagent neutralise from each one another(prenominal), and, by reading the scale on the burette, the volume of reagent can be measured.As the concentration of the reagent is known, the telephone piece of moles of reagent can be measured (since concentration = moles / volume). Then, from the chemical substance equation involving the two substances, the number of moles present in the reactant can be found. Finally, by dividing the number of moles of reactant by its volume, the concentration is calculated.In this case phenolphthalein is the indicator as it stays transparent in the acidic or neutral environment and changes its color into pink in the acidic env ironment.Materials NaOH 5g Sprite 125 ml Phenolphthalein Distillated weewee 250mlApparatus balance burette spatula Erlenmeyer flask Beaker CylinderVariables volume of NaOH type of fizzy drink volume of the fizzy drink precisionProcedure1. relieve oneself all needed apparatus and substances2. Weight 5g of solid NaOH and put it into beaker3. Fill the beaker with 250 ml of distilled water to make 0.5 mol NaOH ascendant4. Fill the burette with NaOH solution and write spate to what level the burette is filled so you can later know how many of the solution was needed to neutralize fizzy drink5. Measure 25 ml of Sprite in the cylinder6. Put 25 ml of Sprite into the flask7. Add to it 4 drops of phenolphthalein8. Put the flask under the burette9. Slowly pour the NaOH solution into the flask with Sprite10. When the color of Sprite is pink stop the titration (it is important to be precise)11. Write down how many NaOH solution was needed to neutralize your fizzy drink12. Repeat steps 4-11 five times to get some more reliable results13. aft(prenominal) you finished your experiment neutralize NaOH solution that you still have and then lily-white the equipment you used during the experiment.Safety guidelines Work areas should be arranged so that a person does not need to travel through a high-hazard area while attempting to exit the laboratory during an emergency. Eyewashes and showers must be accessible to all chemical laboratories. Do not consume food and drink in the laboratory. Wear your googles and gloves to protect your eyes and skin Move in the labolatory carefully Keep the labolatory clean in order to prevent any accidents Pay particular attention to the protection of eyes and skin be occasion NaOH can couse damage to your. Confine long hairc sensh while working in a labolatory. Do not panic if you have done something in a wrong way, just report your teacher and do what he/she has said Flush away all accidentally spilled substances with water and r eport your teacher Neutralize the remaining substances and remove them from equipment Wear your enclothe while working in labData Collectionnumber of the testInitial quantity of NaOH solution in burette (in ml)Final quantity of NaOH solution in burette(in ml)Quantity of NaOH solution used to neutralize fizzy drink(in ml)Table 1. data collected during the experimentData Processing and PresentationIn order to find the pH of Sprite at first the average quantity of NaOH solution used to neutralize the fizzy drink has to be calculatedmlIn order to make some other calculations ml has to be changed to dm31 dm3 = 1000 mlHence5.18/1000 = 0.00518 dm3Next the number of moles of NaOH solution used in the experiment has to be determined from the formulaWheren is number of molesC is molar concentrationV is volume in dm3HenceNext the number of H+ ions in the solution has to be determined using the following formula, whereH+ is the molar concentrationn is number of moles of H+ ionsV is the volum e of the solutionAs number of moles of OH- ions in the solution is equal to the number of moles of H+ ions, nH+ = nOH- = 0.00259molBy knowing this pH of Sprite can be calculated by using the formula belowpH = -logH+pH = -log0.1036pH = 0.98464ConclusionsThe result obtained in the experiment differs a lot from the reality (pH is approximately 2.75). Even not knowing the proper value of pH of Sprite it is rather obvious that the result is wrong as no substance drank by human can have such a little pH. This would destroy our organism and therefore could not be sold as a fizzy drink. The percentage error equalsThis is a huge difference and it can be explained by a number of reasons1. we did not catch the involve moment of neutralization but the moment, when the mixture was already basic so, this difference in time can be crucial2. little differences in measurements during the experiment could also be the cause of mistake3. the time when the color of phenolphthalein did not disappear cou ld be measured wrong and that can be another cause of mistakeSumming up these sources of mistake could not change the result in such a great extend 279%. Although the results of the experiment were imprecise, the aim was partially achieved. Sprite was proved to have acidic pH.EvaluationThe experiment could be done on some greater amounts of Sprite so that the results would be more precise. Although 5 tests were made, maybe some more should be done to make the data collected during the experiment more reliable. Besides that it is hard to find some other ways to make the experiment better or more reliable as the titration method is quite precise and the results should not differ much from the reality.Sources chemistry for the IB Diploma (standard and higher level) by Geoff Neuss Chemistry (second edition) by John Green and Sandru Damji www.en.wikipedia.org entry titration