Experimental Error Burette
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than where it really is. Looking up titration errors and effects at the meniscus causes it to appear lower than it really is. 3. Delivering the liquid too rapidly, so that drops form on the side of the buret. 4. Not reading the buret properly or to the correct number of decimal places. Buret Menu Laboratory Information General Chemistry Help Homepage
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Sources Of Error In Redox Titration
& Garden Local Businesses News & Events Pets Politics & Government titration limitations Pregnancy & Parenting Science & Mathematics Social Science Society & Culture Sports Travel Yahoo Products International Argentina Australia titration error calculation Brazil Canada France Germany India Indonesia Italy Malaysia Mexico New Zealand Philippines Quebec Singapore Taiwan Hong Kong Spain Thailand UK & Ireland Vietnam Espanol About About Answers Community Guidelines http://chemed.chem.purdue.edu/genchem/lab/equipment/buret/error.html Leaderboard Knowledge Partners Points & Levels Blog Safety Tips Science & Mathematics Chemistry Next List at least three possible sources of error in a titration? experiment and, for each, explain whether the error would result in a calculated molarity that is too high or too low. Follow 3 answers 3 Report Abuse Are you sure you want to delete https://answers.yahoo.com/question/index?qid=20130615161006AAoRNC8 this answer? Yes No Sorry, something has gone wrong. Trending Now Dylan Rieder Mike Pence Meghan Trainor Keanu Reeves Fantasy Football 2016 Crossovers Meredith Vieira Rush Limbaugh Credit Cards Ben Affleck Answers Relevance Rating Newest Oldest Best Answer: 1. The addition of too much acid/base. This will increase the volume or ml you added, which will decrease the molarity. Too low. That is why you want it a very "light" color, not a dark rich one. 2. What you are using to titrate it not pure. For example, If you are supposed to be using 1 M of NaOH to titrate vinegar, and the NaOH has something like a small amount of HCl in it because last lab you forgot to clean the beaker you were holding it in (which perviously had some HCl). This would mean that the molarity is much smaller, because there are other impurities in the same amount of solution. This results in a too low calculated molarity. Your standard solution needs to be accurate! 3. The last error is
error'). Experimental uncertainty arises because of: Limits in the how exact the measuring apparatus is. This is the precision of the apparatus. Imperfections in experimental procedures. http://www.avogadro.co.uk/miscellany/errors.htm Judgements made by the operator. When can my results be said to be precise? If you repeat a measurement several times and obtain values that are close together, your results are said to be precise. If the same person obtains these close values, then the experimental procedure is repeatable. If a number of different people carry out the same measuring procedure and the values are close the experimental error procedure is reproducible. What is a systematic error? A systematic error is one that is repeated in each measurement taken. If this is realised after the experimental work is done, it can be taken into account in any calculations. What are random errors? Even the most careful and experienced operator cannot avoid random errors. However, their effect can be reduced by carrying out a measurement many times (if errors in titration the opportunity exists) and working out an average value. Let's look in more detail at 'built-in' uncertainty of some laboratory equipment... Some measurement uncertainties are given below: EquipmentMeasurement to the nearest: Balance (1 decimal place)0.08 g Balance (2 decimal place)0.008 g Balance (3 decimal place)0.0008 g Measuring Cylinder (25 cm3)0.5 cm3 Graduated Pipette (25 cm3, Grade B)0.04 cm3 Burette (50 cm3, Grade B)0.08 cm3 Volumetric Flask (250 cm3, Grade B)0.2 cm3 Stopwatch (digital)0.01 s Calculating the percentage uncertainty (often called percentage error) ... Now try calculating the following percentage uncertainties... 1.00 g on a 2 decimal place balance 10.00 g on a 2 decimal place balance 1.00 g on a 3 decimal place balance 10 cm3 in a 25 cm3 measuring cylinder 25 cm3 in a 25 cm3 measuring cylinder 25 cm3 in a 25 cm3 graduated pipette (Grade B) 25 cm3 in a 50 cm3 burette (Grade B) 250 cm3 in a 250 cm3 volumetric flask (Grade B) 50 s on a digital stopwatch 8% 0.8% 0.08% 5% 2% 0.16% 0.32% 0.08% 0.02% Comparing uncertainties like those calculated above 'might' help you to decide which stage in an experimental procedure is likely to contribute most to the overall exper