Density: a characteristic Property Fides Ybanez Abstract
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- Density: A Characteristic Property Fides Ybanez Abstract
- Liquid Substance Density (g/mL)
- Liquid Substance Acetone Ethyl Acetate Hexane
- Mass of Empty Vial + Stopper (grams)
- Mass of Vial with Liquid and Stopper (grams)
- Mass of Liquid (grams)
- Volume of Liquid (mL)
- Density of Liquid (g/mL)
- Accepted Density (g/mL)
- Accepted Density of Liquid (g/mL)
- Trial 1 Trial 2 Trial 3
- Mass of Test Tube with Unknown Liquid and Stopper (grams)
- Volume of Unknown Liquid (mL)
- Mean Density of Unknown (g/mL) 0.905 Average Deviation
- Substance Silicon Tin
- Trial 3 Mass of Container (grams)
- Mass of Container and Solid (grams)
- Volume of Water and Solid (mL)
- Mass of Remaining Solid (grams)
- Average Deviation 0.563 2.1222 Error (%)
- Bibliography
            Density: A Characteristic Property
Fides Ybanez Abstract The objective of this experiment was to know how to determine density and understand that density characterizes specific substances. Mass, for both liquid and solid, was measured using an electronic analytical balance while the volume for liquid used a volumetric pipette. Since the solids were irregularly-shaped, water displacement method of measuring its volume was used. The experiment was divided into two parts. The first part was determining the densities of liquids such as acetone, ethyl alcohol, ethyl acetate and water. The density of an unknown substance was also determined by measuring its mass and volume. The results showed a density of 0.899 ± 0.01 g/mL which is characteristic of ethyl acetate. The second part determined the densities of tin and silicon. From these densities, the density of germanium was calculated at 72.53 ± 0.02 g/mL. Introduction Density is a physical property and is one of the different ways to identify substance because each substance has unique density. (http://www.elmhurst.edu/~chm/vchembook/120Adensity.html) Density is an intensive property which means it is a property that is independent of the amount of matter. Density is the ratio between mass and volume. It tells whether a substance is compact or loosely packed. Mathematically, density is mass divided by its volume: m D = V Where:
D is the density; M is the mass; and V is its volume.
Since density is a way of identifying substances, it will tell the identity of the unknown substance. If the density obtained will be close to any of those listed in Table 1-1, then the identity of the substance will be known. Experimental Methods Measurement of the mass was done using an electronic analytical balance with an accuracy of 0.0001 and volume measurements were done using 1-mL volumetric pipettes and pipettors. A previously cleaned and dried empty vial with stopper was weighed in the balance. Using a 1.00-mL volumetric pipet, a liquid samples was pipetted and placed in the weighed vial. This was repeated for all liquid samples and for each liquid sample, three trials were prepared and measured. The same procedure was done for the unknown liquid sample. All data are recorded in Table 1-2. For the density of solids, an empty 25-mL beaker was weighed. Enough amount of solids were placed in the beaker and weighed. A 10-mL graduated cylinder was half-filled with water and the solid was placed in it. The amount of solid placed was enough to make the water rise to about 3 mL. The same procedure was done for both solids used and three trials for each solid were done. Data for this part of the experiment are recorded in Table 1-3. The density of germanium was obtained from the densities of tin and silicon. Results Part A of the experiment is the determination of densities of different liquid substances. The mass and volume obtained from this experiment and the calculated densities of the liquid substances are shown in the table below. Table 1-2. Mass, Volume & Densities of Liquid Substances.
Density was calculated using the formula D=m/V. A sample calculation of the density of acetone using trial 1 is shown below. m mass of acetone 0.8048 g D = = = = 0.805 g/mL V Volume of acetone 1.00 mL
Mean Density of Acetone = 3 0.8048 + 0.8736 + 0.8108 = = 0.830 g/mL 3
Calculated absolute deviation (based on accepted densities in Table 1-1) and percent error on densities of liquid substances are shown in Table 1-3 below. Table 1-3. Deviation and Percent Error on Densities of Liquid Substances.
Calculation for the percent error for acetone is shown below. It uses the formula: ⃒ Accepted Value – Experimental Value ⃒ Percent Error = -------------------------------------------------- x 100 Accepted Value
= ------------------------- x 100 = 4.9 % 0.791
Table 1-4 shows the details obtained or the unknown liquid. Table 1-4. Determination of Density of Unknown Liquid.
The unknown substance was found to have a density of 0.905 ± 0.003 g/mL which indicates that it is ethyl acetate. The result showed an error of 0.3%. In Part B, the density of solids were obtained and were used to calculate the density of germanium. The data from the experiment are shown in Table 1.5 below. Table 1.5. Determination of Density of Silicon and Tin.
The density obtained for silicon is 2.33 ± 0.563 g/mL with an error of 24% and that of tin was 6.833 ± 2.1222 g/mL with an error of 29%. The calculated density of germanium based from the data above, is 4.82 g/mL ± 0.503 g/mL. The calculation was obtained as follows: Atomic Number of Ge - Atomic Number of Si Density of Ge - Density of Si --------------------------------------------------------- = ------------------------------------- Atomic Number of Sn - Atomic Number of Si Density of Sn - Density of Si 32 - 14 Density of Ge - 2.33 -------------- = ------------------------------ 50 - 14 7.31 - 2.33
-------------- = ------------------------------ 36 4.98 ( 18 ) ( 4.98 ) = ( 36 ) (Density of Ge - 2.33 ) 89.64 = 36 (Density of Ge) - 83.88 ( 89.64 + 83.88 ) Density of Ge = ---------------------- = 4.82 g/mL 36
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For Books: Bird, W.Z. 1990. Ecological aspects of fox reproduction. Berlin: Guttenberg Press. For chapters in books: Smith, C.J. 1989. Basal cell carcinomas. In Histological aspects of cancer, ed. C.D. Wilfred, pp. 278-91. Boston: Medical Press. Directory: school -> jchs -> staff staff -> Class: World History staff -> Class: World History staff -> Class: World History staff -> Unit 5 Period 6 Review The Big Idea staff -> - staff -> Class: World History staff -> American History Name staff -> Class: American History staff -> Class: us history Name Download 48.51 Kb. Share with your friends:
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