How accuracy may be ensured in techniques used Essay

M1 Explain how accuracy may be ensured in the techniques utilise Cynthia Nzeh labor movement 11) Discuss how your choice of equipment and how it unnatural the accuracy of your method. Discuss good plentytric technique.2) Calculate the implement faulting for the method used.3) Given the value prognosticated by the senior technician take aim your illusion and comment on this error in relation to the apparatus error of the method. In the titration, I used these available instruments to ensure my results would be as accurate as possible. Volumetric buret This instrument was modify with the atomic number 11 hydrated oxide solution that would be gradually added to the vinegar solution.The buret was used instead of a measuring cylinder as it gives a finer volume reading. It has a ten-strike which enables the user to quickly and con fontrably stop the amount of sodium hydrated oxide solution that pours out. However development a piston burette instead of a volumetric burett e may have increased the chances of gaining more than accurate results. This is be stool the piston burette delivers precision bore and plunger.White tile The tile was used to be able to observe the blazon change of the solution in the conelike flask better. By placing the white tile it allowed us to see the colour change more easily and quickly therefore increasing our chances of stopping point the burette tap on metre and giving us surrounding(prenominal) and possibly more accurate results. If non clear composition was used or no paper at all, the colour change of the solution would not have been spotted as quickly therefore increasing the time taken to close the burette tap to stop sodium hydrated oxide organism added to the vinegar solution. The increase of sodium hydroxide solution would believe that the results obtained would not be the accurate or close to the accurate value. funnel This piece of equipment was added to the top of the burette and it was used to channe l the sodium hydroxide solution into the burette. The mouth of the burette was too small to pour the sodium hydroxide solution in safely so the plastic funnel was used to prevent every spillage of the solution and enabled the sodium hydroxide solution to be poured into theburette with precision and no spillage. A disposable paper funnel would not have been an appropriate piece of equipment to use, this is because the paper funnel would have absorbed some of the correctly measured sodium hydroxide solution (liquid) and changed the total volume of the sodium hydroxide passing into the burette. The funnel is then removed before the titration takes place this is to prevent whatsoever extra droplets, of the solution remaining in the funnel, to be added to the solution as it could allude the overall volume in the burette.Conical flask The conic flask was used to store the vinegar with drops of phenolphthalein before sodium hydroxide was added to the solution through the burette. A coni cal flask was the most pattern piece of equipment to use. The destine head minimises the risk of splashes from the flask, this means that the solution form in the flask and does not come into contact with experimenter. Using a conical flask over a beaker is more ideal. This is cod to the feature that a beaker has a wide open mouth which means that solutions bathroom splash out when poured in. Also, the shape of the instrument make it is easier to spin around the contents of the flask.Bulb pipet (and filler) This instrument was used to measure out 25.0cm3 of sodium hydroxide to be added to the conical flask. There is a line of business of meniscus which indicates where the volume should be, this makes the pipette produce an accurate 25.0 volume. The pipette has a narrow portion which slows down the speed at which the solution fascinates drawn up. This enables the volume to be more accurate as it is easier and quicker to stop the pipette drawing up more of the solution after drawing up the desired amount.A measuring cylinder may have as well as been used and may be more ideal than the bulb pipette. This is due to the fact that it has a measuring scale and the amount poured into the instrument is more controlled compared to the bulb pipette as this only has one line of amount and it is tricky to get a solution to fall on the line of the meniscus. Good Volumetric TechniquesTo achieve a good volumetric technique, the experimenter necessitate to be able to correctly complete certain procedures.Before inauguration an experiment, it is good to calibrate some(prenominal) equipment that needs calibration. This ensures that results obtain will be as accurate as possible or as pricy to the true value. All equipment should be inspected to ensure that there are no chips, cracks or general damage to the equipment as these could cause problems during the experiment which could affect the overall results gained.Equipment such as burettes, pipettes, flasks and b eakers must be rinsed with di notwithstandinged water to get rid of any impurities in the equipment. If solutions are to be poured in any piece of equipment then the equipment should also be rinsed out with the solution being used, this will maintain the pH level in the instrument. Once a solution is transferred from the pipette to the flask, touching the tip of the pipette on the side of the flask will drain any extra drops that may still remain on the tip of the pipette.When filling up the burette it is fundamental that a funnel is used, however as the solution reaches the 0 grease it is ideal that the funnel be removed and a pipette used instead to reach the 0 mark, this is to achieve greater precision. During the experiment, it is important to swirl the flask continuously with one hand whilst the other hand opens and closes the tap of the burette, this allows the solution to mix well enough for the colour change to be observed quicker.The titrant should be added in drop by dro p as it reaches the endpoint as it prevents too much of the solution in the burette to be added to the solution in the conical flask. Also, the tap should be bar properly to prevent any extra unwanted solution from gushy out. The burette and pipette must be read at center level to gain the actual result. To ensure reliability, the experiment should be perennial until a concordance amid two results is acquired.Apparatus errorTo calculate the apparatus error the equation isMaximum errorMeasure protect25cm3 pipette = ( 0.1cm3 25) x nose candy = 0.4Burette = ( 0.15cm 22.75) x 100 = 0.66 kitty Balance = (0.01 4.05) x 100 = 0.25Volumetric flask = (0.1 200) x 100 = 0.05= 1.36% apparatus errorExperimental error = 100 x (real effect experiment answer) Real answer100 x (0.056 0.0546)0.056100 x 0.0014 = 2.5%0.056The experimental error is greater than the apparatus error. This could have been down to a number of different factors. Too much sodium hydroxide may have been added to the solution which could have changed the volume of sodium hydroxide used. The burette could have been read wrong and not at the same center level or from the bottom of the meniscus line. These faults may have been the cause of the experimental error or they may have added to the experimental error and this is why the experimental error is much greater than the apparatus error.Task 2 & 3There were certain procedures done in tack to ensure the results obtained would be as accurate as possible.Flame runnelBefore beginning the experiment, the wire loop is dipped into dilute hydrochloric dot then held in a Bunsen burner flame. This is to get rid of any residue remaining of the loop. Each test tube was correctly designate to avoid a mix up.The solutions where look at behind a white background, this was to enable the correct colour to be identified easier. distinct instruments for different solution were used.Food testFor this test it was important to confine the amount of diet sa mples used equal for each food group. The food samples were placed in separate pellets to avoid cross contamination between the foods. Each test tube was correct labelled to avoid a mix up.Equal drops of indicators were added to each food sample.Sourceshttp//nobel.scas.bcit.ca/courses/wpmu/chem0011/files/2010/06/Lab8-Introduction-to-Volumetric-Techniques-I.pdf http//chemwiki.ucdavis.edu/Analytical_Chemistry/Quantitative_Analysis/Titration http//www.thestudentroom.co.uk/showthread.php?t=363038http//wiki.answers.com/Q/How_do_you_calculate_percentage_error_for_equipment http//www.chemguide.co.uk/inorganic/group1/flametests.html