Experiment 2 Physical Properties: Density 1. What is the purpose from the experiment? 2. Write down briefly the experimental procedure. I 3. Answers the following pre-lab questions. Write the definition of Density. The density of gold is 19,3 grams per cubic centimeter. What is the mass of a bar of gold in kilograms that measures 6 inches x 4 inches 2 inches?
CHEM111P-EXP2-201920 Suved to my Mac Mawings Review View MO Atte Ааньсао Лавьсами AaBb scious True Bote Experiment 2 Physical Properties: Density Introduction Density: is a physical property of a substance and is often used as an aid to its identification Density (p) is defined as the ratio of the mass (m) of a substance to the volume (V) occupied by that mass, Mass m Density or D=---- Volume The Sl-units of density is (Kg/m) but there are other units like: (g/emor (g/mL) (1 cm) - 1 mL) Apparatus/Reagents Required Analytical balance, glass rod, buret, clamp, stand, tap water, beakers, 10 mL volumetric pipet, safety bulb, and thermometer Experimental Procedure 1. Density of glass. 2. Measure and record the mass of a glass rod. b. Add approximately 20-25mL of water to a 50 ml buret. sal
-perimental Procedure 1. Density of glass. a. Measure and record the mass of a glass rod. b. Add approximately 20-25mL of water to a 50 mL buret. c. Carefully read and record the liquid level at the bottom of the meniscus to the nearest 0.05 mL, making sure your line of sight is horizontal. Note: The correct way to read the volume of a liquid is to hold the graduated cylinder with the meniscus at eye level as shown in the drawing. Always read the level of the liquid at the bottom of the meniscus. d. Tilt the buret and carefully lower the glass rod to the bottom of the buret. Remove any air bubbles that may appear. e. Read and record the final water level in the buret. f. From this volume change, and the known mass, calculate the density of the glass rod and record it on your report form. 2. Thickness of Aluminum Foil I
The volume of a rectangular solid is given by the product of its length, width and depth (thickness). If the object's density and mass are known, its thickness can be calculated if the length and width are measured. a. Obtain a rectangular or square sheet of aluminum foil (whichever is available in the laboratory). b. Measure the length and width of the foil to the nearest 0.05 cm, using along ruler or a meter stick. Record your data on the report form. C. Fold the foil several times and weigh it on the analytical balance. Record its mass d. Use your data and the density of aluminum (2.70 g/cm3) to calculate the thickness of your foil. e. Record the thickness of the foil in centimeters, meters and micrometers. 3. Density of a liquid The density of a liquid can be determined from its mass and an accurately measured volume using a volumetric pipette. A volumetric pipette is simply a glass tube with an enlarged barrel. The tip of the pipette is constricted and the upper part of the pipette tube has a calibration mark to which it is killed. When the pipette is filled and the liquid level (the bottom of the meniscus) is at the calibration mark, the pipette will deliver the indicated quantity of liquid. Note: The pipet is never filled by mouth suction but only by using pipet filler. a. Before use, the pipette must be clean. This can be checked by filling the pipette with water and allowing the liquid to drain. No water drop lets should be observed on the inner walls. b. Determine and record the mass a clean dry empty 50 mL beaker in the balance. c. Carefully pipette 10.00 mL of water into the empty beaker. d. Determine and record the mass of the beaker and its contents by using the balance. Focus
CHEMI11P-EXP2-201920 Saved to try Me cences Marings Tv View 9 ACD Aa Bbc c. Carefully pipette 10.00 mL of water into the empty beaker. d. Determine and record the mass of the beaker and its contents by using the balance. e. Calculate the density of the liquid. Results/Observations a. Density of glass: Mass of stone Initial volume of graduated cylinder 1 Final volume of graduated cylinder Volume of stone
13 24 AaBbc.code AaBbccdee AaBbcc Aa BbCcDde AaBb AubCCD EO Normal Ne Spacing Heading 1 Heading 2 Title Subtit b. Thickness of aluminum foil: Mass of Aluminum piece Volume of Aluminum piece Length of Aluminum piece Width of Aluminum piece Thickness (cm) Thickness (m) Thickness (um) c. Density of water: Mass of empty beaker Mass of beaker and water Mass of water Volume of water I Density of water (experimentally) Temperature of water Density of water (theoretically ) from handbook Percentage error of density