Calibration of Volumetric Glassware Essay

SummaryIn this experiment, The purpose of this experiment is to investigate the footprintment of the actual flashiness contents of ledgertric glassw atomic number 18. In the beginning of the experiment, the massestric glassware should be clean and dry before used. The masstric glassware, quantity cylinder and pipette should be handled with care and all the precautions were be taken during the experiment was held. This was to ensure to block any fallacys such as parallax error especially while reading weewee meniscus. This experiment moldiness be repeated three times or more and take the average reading to get more accurate data. By using the formulae, the cadence variance and sexual congress standard deviation could be calculated. As the result, the lower the standard deviation, the higher the consistency of an instrument. Although the instrument may measure a given sample, the cherish might need to be altered due to various conditions and errors.ObjectivesThe objecti ve of the experiments was toCalibrate a 10 mL volumetric pipette.Calibrate a 25 mL volumetric pipette.Calibrate a 100 mL volumetric flaskful.Calibrate a 50 mL measurement cylinderIntroductionVolumetric glassware is used to accurately measure volumes. Despite all of the tools and instruments available for the use of beat values of various data, it is unworkable to measure the true value of anything. This experiment is intended to develop a persons capacity to handle volumetric glassware. One mustiness agnize how to handle volumetric glassware to acquirethe best possible data from the equipment used in lab. Although the instrument may measure a given sample, the value might need to be altered due to various conditions. However, with practice and experience, we trick clench very close to the true value, gaining the ability to measure with twain high accuracy and precision. The objective of this experiment is to calibrate a 10mL burette and other volumetric glassware by calculat ing their correction values. By doing so, we can correct systematic errors caused by the burettes or glasswares values. A systematic error is an error in reading the graduated table when a physical quantity is being measured. Systematic errors are caused by the instrument, observer and surroundings. Another main type of error is random error. Random error is an error which occurs when the observer is reading the scale on the measuring instrument.Volumetric glassware is used to accurately measure volumes. In any given experiment, students may come across systematic errors or random errors. Random errors are not able to be corrected by a standard mean because they are not consistent. However, systematic errors are consistent and is able to be detected which allows students to correct the error that was found. So, using uncalibrated glassware will cause a systematic error. This error occurs because the volume reading given by the glassware is exquisitely different than the actual vo lume that is obtained in the glassware. In order to avoid systematic error, it important to calibrate the measuring instrument so that there is a standard value for zero which allows the measurement to be more accurate. calibration of volumetric glassware such as burette is carried out by crusadeing the amount of urine delivered. The temperature of the water used in the calibration must be known since the density of water changes.The purpose of this experiment is to investigate the measurement of the actual volume contents of volumetric glassware. If there is a slight variation in this instrument, it would cause systematic error and thus, the accuracy of results of an experiment or investigation would be affected. All volumetric glassware has marking on it. It is either being marked with TD or TC, which brings the meaning of to deliver and to contain respectively. For example, a pipette has a marking of TD, which means a pipette is markedas a to deliver. Whereas, volumetric flas k has TC as its marking, meaning it is marked as a to contain. A volumetric pipette & measuring cylinder can be calibrated by just measure the water they deliver. As for volumetric flask, the weight of an empty flask is recorded. Next, weigh the flask after filling it with water to the mark. After that, it is crucial to convert the mass to volume. The water density at a temperature will aid this process. The deference of the Volume Occupied by 1.000g of water system Weigh in Air table is deemed necessary throughout the comparison. In order to obtain the true volume of volumetric glassware holds, this formula will be used.This experiment shall be repeated twice or more to enhance accuracy of the results obtained. Besides catching systematic errors, this experiment would aid on the technique and understandings to the correct use of these equipments.Materials transpose pipette, cleaning solution/detergent, beaker, thermometer, distilled water, top loading balance, 10ml volumetric pi pette, 25mlvolumetric pipette, 100ml volumetric flask, 50ml measuring cylinder.Procedure1) Calibration of a volumetric pipette (10ml and 25ml)a) Transfer pipette was obtained. The pipette was cleaned because distilled water does not drain uniformly. A cleaning solution or detergent was used to clean the pipette.b) An empty beaker was weighted. Then, water was filled in the beaker. The temperature was recorded at uniform intervals.c) The 10ml pipette was filled with distilled water until it reaches the calibration mark.d) Water was drained into another beakere) The beaker filled with water was then weighted to find the mass of water delivered from the pipette.f) The following equivalence was used to convert mass to volume Volume(actual) = (grams of water) x (volume of 1g of water in table1)g) Step a f was repeated using 25ml pipette.1)2) Calibration of volumetric flask (100ml)a) A 100ml volumetric flask was cleaned and dried.b) The flask was weighted. Then, water was filled into th e flask. Transfer pipette was used to remove the excess amount of water filled in the flask so that it exactly reach the calibration mark.c) The flask filled with water was weighted to find the mass of water contained in the flask.d) Mass of water was converted to volume using the equation above.3) Calibration of a measuring cylinder (100ml)a) A 100ml measuring cylinder was cleaned and dried.b) The measuring cylinder was weighted. Then, water was filled into the measuring cylinder until it reached the calibration mark. Transfer pipette was also used to remove the excess water.c) The measuring cylinder filled with water was weighted to find the mass of water contained in the measuring cylinder.d) Mass of water was converted to volume using the same equation.Result and DiscussionResulta) Data10mL pipette campaign 1Trial 2Trial 3Mass of flask + water (g)42.6442.6642.66Mass of flask (g)32.7232.7232.72Mass of water (g)9.929.949.94Temperature (oC)282828Actual volume (mL)9.979.999.99 mean( a) volume (mL)9.98Standard Deviation,0.012Relative standard deviation ,/0.00120250mL pipetteTrial 1Trial 2Trial 3Mass of flask + water (g)121.08121.06121.04Mass of flask (g)96.6096.6096.56Mass of water (g)24.4824.4624.48Temperature (oC)282828Actual volume (mL)24.6024.5824.60Average volume (mL)24.59Standard Deviation,0.012Relative standard deviation ,/0.0004910mL pipetteTrial 1Trial 2Trial 3Mass of flask + water (g)158.42158.44158.42Mass of flask (g)57.1857.1657.16Mass of water (g)101.24101.28101.26Temperature (oC)282728Actual volume (mL)101.73101.77101.75Average volume (mL)101.75Standard Deviation,0.02Relative standard deviation ,/0.00019750mL measuring cylinderTrial 1Trial 2Trial 3Mass of flask + water (g)116.48116.48116.48Mass of flask (g)68.1868.1768.18Mass of water (g)48.3048.3148.30Temperature (oC)282828Actual volume (mL)48.5348.5448.53Average volume (mL)48.53Standard Deviation,0.007Relative standard deviation ,/0.000146DiscussionAccording to the tables above, when using 10mL p ipette, the actual volume delivered is 9.98mL and the standard deviation is 0.012. The lower the standard deviation, the higher the consistency of an instrument based in a physics book. Consistent measurements consist of readings that have little or no relative deviation among them. So, when the standard deviation is nearer to zero then this shows that the readings taken are consistent. In order to get a good accuracy, the experiments are make until trial 3. Temperature are remain consistent for all three trial for different glassware that 28C. This experiment expectation is that the glassware will be used to measure runnys at room temperature. Since liquids have a tendency to change volume (at the level of precision of calibrated instruments), then we want the liquid to be at the temperature we are most likely to use so that the calibration will have the most accuracy and we used water since it is caloric equilibrium in surrounding. Another factor that may interrupt the reading is parallax error during the experiment is held. In order to avoid parallax error is the glassware must be weight for another two times. Every scale on the reading instrument must be read properly, it may reduce the fact. The eye must be perpendicular to the reading scale on the same level as the bottom surface of the water meniscus to avoid parallax error. Besides, the weighing bottles are always being capped to avoid evaporation since it is important precaution.ConclusionBased on this experiment , we can conclude that this experiment are to study the calibration to measure the accuracy of volumetric glassware. This experiment also ensure the accuracy of the volumetric glassware for 10 ml and 25 ml pipette, 100 ml volumetric flask and 50ml measuring cylinderReferences*http//gula-gulakapassikecik.blogspot.com/2012/04/calibration-of-volumetric-glassware_24.html?m=1 * www.studymode.com * Lim Peng Chew, Lim Ching Chai, Nexus Bestari Physics, Sasbadi Sdn. Bhd. , 2013, Pg 18,19