INTRODUCTION
1.1 Background of the Experiment
Mass density describes how heavy an object is. Defined by the Greek letter ρ, read as rho, density is a basic yet important physical property of matter. For a bulk body without accounting its existing pores and voids, density is represented by the ratio of its mass and volume. It is given by the equation ρ= massvolume 1.
The SI unit of density is kg/m3. However, its CGS units, g/cm3 or g/ mL, are the most commonly used ones in the laboratory. The conversion is given by
1 gcm3=1gmL=1000 kgm3 [1].
The density of a homogeneous liquid is also defined by the amount of mass per unit volume. Liquid is usually confined in a container, so its volume is relative to the volume of its container
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Carefully clean and dry the pycnometer. B. Weigh the empty pycnometer and its stopper in the balance beam and record the mass. C. Fill the pycnometer with the liquid sample up to its brim, and insert the stopper carefully. Wipe off any excess fluid 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 Volume of Alumina 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 initial volume. C. Carefully drop an alumina ball to the graduated cylinder and measure the new volume. Do this by slightly tilting the cylinder and gently sliding 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 spherical 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 difference 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.
because each of the objects displaced the water by 1 mL, their mass over that mL is their density.
Purpose: To become familiar with the International System of Units and common laboratory equipment and techniques. To learn how to determine volume, mass, length, and temperature of a wide variety of items. To learn how to calculate density and concentration of dilutions.
Density is the amount of matter per unit of measurement (Merriam-Webster. Merriam-Webster, n.d. Web. 26 Aug. 2016.). If water has a density of 1.0 g/mL and you place a substance with a density of 1.8 g/mL the substance will sink because it is denser than water. Density is often measured in g/cm^3 or g/mL because the formula for density is D=m/v.
Purpose: Weighing objects. Figuring out the density with an object by calculated volume and Archimedes’ Principle.
5. Calculate the density of an object that has a mass of 43 g and a volume of 56.0 mL.
I took the graduated cylinder and started filling it up with water until the bottom of the meniscus was to the the 100.0 mL mark with the assistance of a dropper pipet. I then took the 13 x 100 mm test tube and slowly poured the water from the graduated cylinder into the test tube until it was full to the top. I then poured the water in the test tube out into the sink and put the graduated cylinder on the counter so I can get an accurate measurement of the lower meniscus to record on my data table. I once again followed the same procedure again filling a second test tube with water from the graduated cylinder then setting it on a straight surface to get an accurate measure of the volume to
9. The accepted value for the density of water is 1 g/mL and the accepted density for isopropyl alcohol is 0.786 g/mL. Determine the percent error between your calculated densities and the accepted values for both water and isopropyl alcohol. Record the percent error in Data Table 4.
CHM130 Lab 6 Exploring Density Name A. Data Tables Place your completed Data Tables here Part IIIa (3 points) Volume of water in graduated cylinder (mL)10 mlMass of rubber stopper (g)11.15Volume of water and rubber stopper (mL)16.5 Part IIIb (6 points) Volume of water in graduated cylinder (mL)20Mass of iron nail (g)3.66Volume of water and iron nail (mL)20.5 Part IV (20 points) Type of Aluminum FoilMass (g)Length (cm)Width (cm)Volume (cm3)Thickness (cm)Regular.63g15 cm 10.02 cm.21 cm3.0014 cm Heavy Duty.97g15 cm10.01 cm .36 cm3.0024 cm B. Follow Up Questions Show all work for questions involving calculations. Part I Use the concepts/vocabulary of density to explain why the liquids formed layers in Part I of the procedure. (8 pts)
2. In order to calculate the density of a solid or liquid sample, what measurements are needed?
(Lab: A Penny For Your Thoughts). The density of a matter is equal to the mass divided into the volume. The mass of a matter or object can be found by using a scale. Furthermore, the volume can be found using the method of water displacement. The purpose of finding
In the third stage of this experiment, the density of a liquid was determined and compared to known standards. A 100ml beaker was filled to about half-full with room-temperature distilled water. The temperature of the water in ◦C was recorded in order to compare to known standards later. A 50ml beaker was then weighed on a scale in order to determine mass and recorded. A sample of the distilled water with an exact volume of 10ml was then placed in the 50ml beaker using a volumetric pipette. The 50ml beaker with the 10ml of water was then weighed again and the initial mass of the beaker was subtracted from this mass to obtain the mass of the 10ml of water. With the volume and the mass of the water now known, density was calculated using d = m/V and recorded in g/ml. This process was then repeated to check for precision and compared to standard values to check for accuracy. Standard values were obtained from CRC Handbook, 88th Ed.
D. A sample of gold (Au) has a mass of 26.15 g. Given that the theoretical density is 19.30 g/mL,
Seven various household objects were chosen to measure using a digital gram scale. Each object’s mass was estimated by lab students and recorded in data table 4. A quarter, ball point pen, rubber bulb, large paper clip, green crayon, house key and a copper penny masses were estimated and recorded in data table 4. Each object was placed on the scale individually and its actual measurement was recorded in data table 4. As we started estimating the household objects we were often not correct in our estimations. As we measured more and more objects, we got better in our estimations by comparing objects with known masses and comparing them with the unknown
Record the sample mass in your notebook. Remember to record all digits on the balance. Closed toed shoes and goggles are REQUIRED for the lab
b) An empty beaker was weighted. Then, water was filled in the beaker. The temperature was recorded at uniform intervals.