title: density lab density is an important intensive physical property of matter. by itself or in conjunction with other properties density

Title: Density Lab
Density is an important intensive physical property of matter. By
itself or in conjunction with other properties density can be used to
identify substances. Density is defined as the quantity of matter in a
given unit of volume. This relationship expressed mathematically is;
Density is Mass/ Volume
Purpose: The purpose of this lab is to determine the density of a
metal object and two (2) liquids. The correct use of significant
digits and proper laboratory report set up are secondary purposes.
Materials
Procedure:
Part A : The Density of a Metal Cylinder
1.
Measure the mass of a metal cylinder on an analytical balance. Be
careful not to touch the metal directly with your hands prior to
deterring the mass. Record the mass as given on the balance in the
data table.
2.
Measure the length and diameter of the metal cylinder with a
centimeter ruler. Your measurements should have TWO decimal
places. Record the measurements in the data table.
3.
Put exactly 10.0 mL of water in a 50.0 mL graduated cylinder.
Carefully place the metal cylinder in the graduated cylinder.
Record the initial and final water levels to one decimal place in
the data table.
Part B: The Density of Liquids
1.
Determine the mass of an empty dry 50.0 mL graduated cylinder.
Record the mass in your data table.
2.
Place exactly 10.0 mL of water in the empty 50.0 mL graduated
cylinder. Record this mass in the data table.
3.
Dry the graduated cylinder and place exactly 10.0 ml of ethanol in
the empty 25.0 mL graduated cylinder. Determine the mass of the
graduated cylinder and ethanol and record this in the data table.
Data
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Part A
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Mass of metal cylinder
Length of cylinder
Diameter of metal cylinder
Initial volume of water
Final volume of water
Part B
Mass of cylinder + 10.0 mL of water
Mass of cylinder and 10.0 mL of ethanol
Calculations:
Show all work and include units and sig digits.
1. Calculate the volume of the metal cylinder from its dimensions
using the formula
V = r2L
2. Calculate the density of the metal cylinder using the volume
obtained in the previous question.
3.Clacuate the volume of the metal cylinder from its water
displacement.
4.Calculate the density of the metal cylinder using the volume in the
previous question.
5. Calculate the mass of 10.0 mL of water.
6. Calculate the density of water.
7. Calculate the mass of 10.0 mL of ethanol.
8. Calculate the density of ethanol.
9. Obtain the true value for the densities from your instructor.
a.
Calculate the % error for the density of the metal with each
method. What was your sample of metal?
b.
Calculate the % error for the density of water.
c.
Calculate the % error for the density of ethanol.
Questions:
1. Which method for the determination of density of the metal was most
accurate? Why?
2. Specific gravity is defined as the mass of a substance divided by
the mass of an equal volume of water (or the density of the substance
divided by the density of water). Determine the specific gravity of
ethanol.
3. How would your results be affected if a 25.0 mL graduated cylinder
was used and exactly 15.0 mL of your liquid was used? Be specific.
4.How would your value for the density be affected if some water