Density - Example 3
Question: The density of the liquid can be determined graphically by consecutively adding small portions of liquid to a graduated cylinder, reading the volume and weighing the cylinder. A graph of mass vs. volume of liquid added will produce a straight line with a slope equal to the density. The data shown below was collected for an unknown liquid. Calculate its density.
| Volume Reading (ml)
| Mass Reading (g)
|
| Just the graduate
| 0.00
| 26.32
|
| One portion added
| 2.65
| 30.53
|
| A second portion added
| 5.21
| 34.65
|
| A third portion added
| 7.56
| 38.02
|
Answer: A plot of mass vs. volume added is constructed and a best fit line drawn.
Taking two points from the line (not data points) and determining the slope between them gives:
As the slope is equal to the density, the density of the liquid is 1.57 g/ml.
This completes the background. Proceed to the prelab.
