How accuracy may be ensured in techniques used Essay

M1 Explain how accuracy may be retardd in the techniques use Cynthia Nzeh labor movement 11) Discuss how your choice of equipment and how it touched the accuracy of your rule. Discuss well be retaind hatfultrical technique.2) Calculate the apparatus misapprehension for the method employ.3) Given the value cypherd by the senior technician calculate your wrongful conduct and chit chat on this error in affinity to the apparatus error of the method. In the titration, I used these available instruments to ensure my results would be as true as possible. volumetrical buret This instrument was filled with the atomic number 11 hydrated oxide stem that would be stepwise added to the vinegar consequence.The buret was used preferably of a measuring cylinder as it gives a finer volume exacting. It has a woo which enables the user to quickly and tardily s elucidate the amount of atomic number 11 hydroxide solution that pours out. However using a plumbers helper burette i nstead of a volumetric burette may bear increased the chances of draw ining more(prenominal) accurate results. This is because the piston burette delivers precision bore and plunger. innocence tile The tile was used to be able to observe the colour salmagundi of the solution in the conic flask better. By placing the white tile it allowed us to see the colour exchange more easily and quickly therefore change magnitude our chances of closing the burette tap on time and giving us terminal set(predicate) and possibly more accurate results. If non suck written report was used or no paper at all, the colour change of the solution would non possess been descry as quickly therefore increase the time taken to close the burette tap to stop sodium hydroxide beingness added to the vinegar solution. The increase of sodium hydroxide solution would mean that the results retrieveed would non be the accurate or close to the accurate value.Funnel This piece of equipment was added t o the top of the burette and it was used to channel 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 both 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 permit been an appropriate piece of equipment to use, this is because the paper funnel would have absorbed approximately of the correctly measured sodium hydroxide solution (liquid) and changed the total volume of the sodium hydroxide going into the burette. The funnel is whence removed to begin with the titration takes place this is to prevent some(prenominal) pleonastic droplets, of the solution remain in the funnel, to be added to the solution as it could affect the boilers suit volume in the burette.Conical flask The conical flask was used to store the vinegar with drops of phen olphthalein before sodium hydroxide was added to the solution with the burette. A conical flask was the virtually apotheosis piece of equipment to use. The narrow vanguard minimises the risk of splashes from the flask, this means that the solution remains in the flask and does not commence into contact with experimenter. Using a conical flask over a beaker is more ideal. This is overdue to the fact that a beaker has a wide open mouth which means that solutions can splash out when poured in. Also, the decide of the instrument make it is easier to swirl 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 meniscus which indicates where the volume should be, this makes the pipet produce an accurate 25.0 volume. The pipette has a narrow portion which slows down the hotfoot at which the solution fetchs 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 to a fault been used and may be more ideal than the myeline pipette. This is due to the fact that it has a measuring case and the amount poured into the instrument is more controlled compared to the bulb pipette as this only has unitary line of measurement and it is tricky to get a solution to fall on the line of the meniscus. Good Volumetric TechniquesTo get hold of a good volumetric technique, the experimenter necessarily to be able to correctly clear current procedures.Before opening an experiment, it is good to calibrate any equipment that needs calibration. This ensures that results obtain pass on be as accurate as possible or as near 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 af fect the overall results gained.Equipment such as burettes, pipettes, flasks and beakers must be rinsed with distilled 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 take in the instrument. Once a solution is transferred from the pipette to the flask, touching the current of air 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 significant that a funnel is used, however as the solution crapes the 0 mark 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 measurable to swirl the flask continuously with unmatchable hand whilst the other hand opens and closes the tap of the burette, this allows the solution to mix well co mplete for the colour change to be observe quicker.The titrant should be added in drop by drop 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 omit properly to prevent any extra unwanted solution from pouring out. The burette and pipette must be read at eye aim to gain the actual result. To ensure reliability, the experiment should be repeated until a concordance amidst two results is acquired.Apparatus errorTo calculate the apparatus error the equation is utmost errorMeasure Value25cm3 pipette = ( 0.1cm3 25) x coulomb = 0.4Burette = ( 0.15cm 22.75) x 100 = 0.66 Mass Balance = (0.01 4.05) x 100 = 0.25Volumetric flask = (0.1 200) x 100 = 0.05= 1.36% apparatus error observational error = 100 x (real resolution experiment answer) Real answer100 x (0.056 0.0546)0.056100 x 0.0014 = 2.5%0.056The data-based error is greater than the apparatus error. This could have been d own to a number of unalike 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 eye 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. business 2 & 3There were certain procedures done in order to ensure the results obtained would be as accurate as possible.Flame runBefore beginning the experiment, the wire loop is dipped into deoxidise hydrochloric acid then held in a Bunsen burner flame. This is to get rid of any residue remaining of the loop. Each rill tube was correctly labelled to reduce a mix up.The solutions where look at behind a white background, this was to enable the correct colour to be set easier. Different instruments for different solution were used. victuals testFor this test it was important to maintain the amount of food samples used peer for each food group. The food samples were put in separate pellets to keep down breed 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