Lab Report on Density Measurement

INTRODUCTION 1. 1 Background of the Experiment pack closeness describes how heavy an object is. Defined by the Greek letter ? , state as rho, concentration is a basic yet important bodily fitty of matter. For a bulk body without accounting its existing pores and voids, absorption is represented by the ratio of its throng and brashness. It is given by the equation ? = cud stack 1. The SI unit of parsimoniousness is kg/m3. However, its CGS units, g/cm3 or g/ mL, argon the most commonly utilize unmatcheds in the research lab. The conversion is given by 1 gcm3=1gmL= atomic number 60 kgm3 1.The assiduity of a alike bland is similarly defined by the amount of fold per unit volume. mobile is usually confined in a container, so its volume is relation back to the volume of its container 2. There be various instruments that are used to completely mensuration the closeness of substances the most commonly used are the densitometers, pycnometer and hydrometers 3. In th is experiment, the density of selected liquified samples will be measurable victimization a pycnometer. 1. 2 Objectives of the Experiment 1. To determine the density of low boiling prime liquid samples by measuring their troop at controlled volume 2. o determine the density of alumina by measuring the crowd and volume of variously wrought alumina clunks and 3. to buttocksvas the density deliberate from the given samples with the measuring rod density at board temperature. 1. 3 significance of the Experiment At the end of the experiment, the research laboratory performer is expected to moderate the following 1. the density of selected liquids and material at a given temperature and 2. the proper method of measuring the volume and consequently the density of irregularly shaped objects using pee displacement method.REVIEW OF RELATED LITERATURE absorption is one of the most important and commonly used physical properties of matter. It is an intrinsic spot which is re presented by the ratio of a matters mass to its volume 3. Density was purportedly discovered by the Greek scientist Archimedes in an unusual circumstance. According to stories, King Hiero of Syracuse asked Archimedes to determine whether his new capital is made of pure gold or not. It was seemingly impossible to order the gold percentage that composed the crown because chemical analysis was allay unstudied in those times.One day, when Archimedes was enjoying himself to a bath, he observed that the further he went down the tub, the less(prenominal)er he weighed and the higher(prenominal) the water level rose up. He then came to the realization that he could determine the ratio of the mass of the crown and the volume of water displaced by the crown, and compare it to the rate measured from the pure gold sample. Hence, density and the principle behind it were revealed 4. Density is underage on many factors, one of which is temperature. It specifically decreases with increasing tem perature.This is because an objects volume undergoes thermal expansion at increasing temperature while its mass remains unchanged. This terminations to a decrease in density 1. When matter undergoes a transformation to a different phase, it undergoes an abrupt change in density. The passage of molecules of matter to a less random form, say from gas to liquid or from liquid to solid, causes a drastic increase in the density. However, at that place are substances which behave differently from this density-temperature relationship, by which one example is water. The superior density achieved by water molecules are at 4C.At temperatures higher or lower than 4C, its density slowly decreases. This brand names ice less dense than water, a property not commonly exhibited by early(a) liquids 3. METHODOLOGY 3. 1 fabrics A. Pycnometer, 25-mL B. Graduated cylinder, cytosine0-mL C. Graduated cylinder, 250-mL D. Beaker, 250-mL E. Low boiling point liquids (acetone, 70% solution ethyl alco hol, 70% solution isopropyl alcohol), 30 mL F. Distilled water G. Two sets of alumina balls (small cylindrical, large cylindrical and large ball-shaped balls) H. Analytical balance beam 3. 2 Determining the atomic pile of a 25-mL Liquid 5 A.Carefully clean and dry the pycnometer. B. Weigh the empty pycnometer and its stopper in the balance beam and magnetic disk the mass. C. Fill the pycnometer with the liquid sample up to its brim, and insert the stopper carefully. Wipe off any excess mobile on the sides of the pycnometer with a clean cloth or tissue. D. Balance and record the mass of the filled pycnometer plus the stopper. E. Empty the contents of the pycnometer in a clean beaker. F. Make three trials for each liquid. 3. 3 Determining the Mass and deal of aluminum oxide Balls 5 A. Measure the mass of each alumina ball in the balance beam. B.Add distilled water to the graduated cylinder and record its sign volume. C. Carefully drop an alumina ball to the graduated cylinder and measure the new volume. Do this by approximately tilting the cylinder and gently slew the ball to its side. D. Use the 250-mL graduated cylinder for small cylindrical alumina balls while the 1000-mL cylinder for the large cylindrical and world(a) alumina balls. E. Do the same procedure for the two sets of alumina balls. 3. 4 Calculating the Density of Liquid 5 A. Calculate the mass of the liquid by computing the oddment between the recorded mass of the pycnometer when empty and filled with liquid.B. Calculate the density of the liquid by dividing its obtained mass by the volume indicated on the pycnometer. C. magnetic disk and compare the resulting density of the liquid with the standard value at style temperature. 3. 5 Calculating the Density of aluminium oxide Balls 5 A. Compute for the volume of the alumina balls by subtracting the initial volume from the final volume of water in the graduated cylinder. B. Calculate for the density of the alumina balls by dividing the mea sured mass by the volume. C. Record and compare the resulting density of the alumina balls with the standard value at room temperature. 3. Data and Analysis mesa 1. The mass of the 4 25-mL liquid samples measured in three trials Liquid Volume (mL) Mass (grams) 1ST Trial 2nd Trial 3RD Trial irrigate 25. 0 25. 244 25. 348 25. 359 Acetone 25. 0 20. 131 20. 147 20. 163 ethyl alcohol 25. 0 22. 313 22. 330 22. 337 Isopropyl inebriant 25. 0 22. 025 22. 035 22. 049 Table 2. The volume and mass of the two sets of alumina balls Alumina Ball (based on Size) amaze 1 Set 2 Volume (mL) Mass (grams) Volume (mL) Mass (grams) minor cylindrical 2. 0 5. 813 2. 0 5. 742 heavy(a) cylindrical 8. 5 24. 042 9. 5 23. 42 Large spherical 10. 0 22. 975 9. 0 19. 747 Table 3. Calculation of density of the four liquid samples Liquid Density (grams/mL) 1st Trial 2ND Trial tertiary Trial Water 25. 244 ? 25 = 1. 00976 25. 348 ? 25. 0 = 1. 01392 25. 359 ? 25. 0 = 1. 01436 Acetone 20. 131 ? 25. 0= 0. 80524 20. 147 ? 25. 0 = 0. 80588 20. 163 ? 25. 0 = 0. 80652 ethyl radical Alcohol 22. 313 ? 25. 0= 0. 89252 22. 330 ? 25. 0= 0. 89320 22. 337 ? 25. 0= 0. 89348 Isopropyl Alcohol 22. 025 ? 25. 0= 0. 88100 22. 035 ? 25. 0= 0. 88140 22. 049 ? 25. 0= 0. 88196 Table 4. Calculation of density of the alumina ballsAlumina Ball (based on Size) Density (grams/mL) Set 1 Set 2 Small cylindrical 5. 813 ? 2. 0 = 2. 9065 5. 742 ? 2. 0= 2. 8710 Large cylindrical 24. 042 ? 8. 5= 2. 8285 23. 942 ? 9. 5= 2. 5202 Large spherical 22. 975 ? 10. 0= 2. 2975 19. 747 ? 9. 0= 2. 1941 Table 5. The mean value of the density calculated from the four liquid samples Liquid Mean Value (g/mL) Water 1. 00976 + 1. 01392 +1. 014363 =1. 01268 Acetone 0. 80524 + 0. 80588 + 0. 806523 =0. 80588 Ethyl Alcohol 0. 89252 + 0. 89320 + 0. 893483 =0. 89307 Isopropyl Alcohol 0. 88100 + 0. 88140 + 0. 881963 =0. 8145 Table 6. The mean value of the density calculated for the alumina balls Alumina Ball (based on Size) Mean Value (g/mL) S mall Cylindrical 2. 9065 + 2. 87102 =2. 8888 Large Cylindrical 2. 8285 + 2. 52022 =2. 6744 Large Spherical 2. 2975 + 2. 19412 =2. 2458 Average 2. 8888 + 2. 6744 + 2. 24583 =2. 6027 RESULTS AND DISCUSSIONS The table below shows the obtained densities of the samples in four decimal places. Table 7. Summary of observational densities of the samples Liquid/Material Density (g/mL) at 25C Acetone 0. 8059 Alumina 2. 6027 Ethyl Alcohol 0. 8931Isopropyl Alcohol 0. 8815 Water 1. 0127 Table 8. Accepted values of the density of certain materials at 25C 6 Liquid/Material regulation Density (g/mL) at 25C Acetone 0. 7846 Alumina 2. 7300 Ethyl Alcohol 0. 8651 Isopropyl Alcohol 0. 8493 Water 0. 9970 Accuracy of the result, or the agreement of the observational value to the recognised value, is defined by its percentage misconduct. An experimental result with a percentage error less than 5% is considered to be accurate. This indicates that the laboratory procedure performed in obtaining the said result is scientifically legitimate 7.The close table shows the calculation of the percentage errors of the densities obtained from the experiment relative to the accepted values represented in Table 8. Table 9. Calculation of the percentage error of the experimental densities of the samples Liquid/Material Acetone 0. 7846 0. 80590. 7846 ? 100 = 2. 643% Alumina 2. 7300 2. 60272. 7300 ? 100 = 4. 663% Ethyl Alcohol 0. 8651 0. 89310. 8651 ? 100 = 3. 237% Isopropyl Alcohol 0. 8493- 0. 88150. 8493 ? 100 = 3. 791% Water 0. 9970 1. 01270. 9970 ? 100 = 1. 550%Table 9 shows the percentage errors of the experimental densities computed from the samples. The values indicate that the experimental densities of acetone, alumina, ethyl alcohol, isopropyl alcohol and water at 25C are within 5% error from accepted values, thereby implying that these results are accurate and the procedure used in performing the experiment is correct, consistent and reliable. Small disagreements in the values of experimental and accepted densities can be accounted to factors that could slightly change the density of a material, in which one of these is temperature.The actual room temperature was not actually measured due to personal negligence, and was just anticipate to be 25C. Thus, the standard values that are used to compare with the results might be not be the most appropriate ones relative to temperature. Other factors which could lead to slight discrepancies in density could be the required systematic errors, particularly instrumental and human errors. CONCLUSION AND RECOMMENDATION In general, the experimental densities of all the samples used are significantly close to the standard densities at 25C. Thus, the laboratory rocedure was done correctly and consistently. Small deviations of the results from the accepted values might be due to systematic errors. One of which can be caused by the lack of precision of the analytical balance beam. compassionate errors such as incorrect or inconsistent readings and interpretations of results might also cause these slight disagreements between the standard and experimental values. It is recommended to future laboratory performers to measure the actual room temperature before, while and after conducting the same experiment, to make sure that the temperature is constant all throughout.Temperature is a vital factor that could fix the results of the experiment. Hence, this must not be neglected. Nevertheless, the method of using pycnometer to measure the density of the liquids and water displacement method for the irregularly shaped solids yields accurate and reliable results. REFERENCES 1. Gallova, J. (2006). Density determination by pycnometer. Retrieved July 8, 2012 from Comenius University of Bratislava at http//www. fpharm. uniba. sk/fileadmin /user_upload/english/Fyzika/Density_determination_by_pycnometer. pdf 2.University of mamma Boston, College of Science and Mathematics (2005). Measurement of Density and Archi medes Principle. Retrieved July 4, 2012 from http//www. physicslabs. umb. edu/Physics/sum07/181_Exp9_Sum07. 3. Johnston, J. (2011). Density Definition. Retrieved July 7, 2012 from http//www. densitydefinition. com/ 4. Bell, E. T. (1937). The numeric achievements and methodologies of Archimedes Electronic version. Men of mathematics. Retrieved July 8, 2012 from http//mathdb. org/articles/archimedes/e_archimedes. htmBk03 5. Skyline College, Chemistry 210 Laboratory Manual (2010).Determination of the density of water and unknown solid sample. Retrieved July 7, 2012 from http//www. smccd. edu/accounts/batesa/chem210/lab/labmanual/Density2010. pdf 6. Walker, R. (1998). Density of Materials. Retrieved July 8, 2012 from http//www. simetric. co. uk/index. htm 7. Brooks P. R. , Curl R. F. , Weisman R. B. (1992). analyze the relationship between the mass of a liquid and its volume Electronic version. earlier Quantitative. pages 16-19. Retrieved July 8, 2012 from http//www. terrificscience. org/lessonpdfs/MassVolumeofLiquid. pdf