SNC1P- Chemistry
Mr. Scott
NAME: ______________
LAB: Identifying Substances Using Density
Purpose: To use quantitative measurements like mass, volume and density to identify
unknown substances and analyze the results.
Materials: 100 mL beaker, 25 mL graduated cylinder, balance, three unknown liquids,
dropper, graph paper, ruler, coloured pencils
Procedure:
1) Find the mass of the 25 mL graduated cylinder and record in the Observations section.
2) Fill the beaker approximately ¼ full of Liquid A. Use the dropper to help you fill the
graduated cylinder with exactly 5 mL of liquid A. Measure the mass of the cylinder and
the liquid. Record the mass of 5 mL of liquid A in the Observation chart. (Don’t forget
to subtract the mass of the graduated cylinder!)
3) Repeat Step 2 for volumes of liquid A measuring exactly 10 mL, 15 mL, 20 mL and
25 mL.
4) Repeat Steps 2 and 3 for liquids B and C, filling the Observation chart as you go.
Observations:
(8 marks)
Mass of 25 mL graduated cylinder: ____________________________
Volume (mL)
Mass (g)
Liquid A
5
10
15
20
25
Liquid B
Liquid C
SNC1P- Chemistry
Mr. Scott
Analysis:
Complete a straight line graph of mass vs. volume using a sharp pencil and the graph
paper provided:
(8 marks)
1) Place volume (mL) on the x-axis (horizontal axis), and choose a scale which will allow
you to graph up to 25 mL.
2) Place mass (g) on the y-axis (vertical axis), and choose an appropriate scale which will
allow you to graph beyond your collected data.
3) Plot your data using a different coloured pencil for each liquid. Include a key or
legend on your graph indicating which substance is which colour.
4) Draw a line of best fit through the plotted points for each substance using the
appropriate colour. The line should begin at (0,0) because at 0 ml, there will be 0g.
5) Ensure your graph includes headings, units, and a descriptive title.
SNC1P- Chemistry
Mr. Scott
Questions: answer in full sentences !
1) The independent variable is the part of an experiment that the scientist changes
herself. It is the “cause” in a “cause-and-effect” relationship. What physical property
of the liquids is the independent variable in this lab? (1 mark)
________________________________________________________________________
________________________________________________________________________
2) The dependent variable is the part of an experiment that the scientist measures. It is
the “effect” in a “cause-and-effect” relationship. What physical property of the liquids is
the dependent variable in this lab? (1 mark)
________________________________________________________________________
________________________________________________________________________
3) Density can be expressed as a formula: density (g/mL) = mass (g)
or d = m .
volume (mL)
V
a) On your graph pick one point on the line for liquid A and label it point #1. Write the
volume and the mass of this point below. Use GRASP problem solving to show a full
solution calculating the density of liquid A using the mass and volume of point #1. (5 marks)
GRASS-
b) Pick two more points: one on the line for liquid B and one from liquid C. Use the
mass and volume values of these points to calculate the density of liquids B and C. You
do NOT need to use GRASS. (4 marks)
Liquid B
Liquid C
SNC1P- Chemistry
Mr. Scott
5) Compare your average densities to the chart below to identify the 3 liquids. Whichever
numbers match the closest will be the substance.
(3 marks)
Substance
Ice
Glycerol
Distilled Water
Vegetable Oil
Isopropanol
Density (g/ mL or g/mL3)
0.92
1.26
1.0
0.92
0.79
Liquid A: ______________ Liquid B: ______________ Liquid C: _______________
Name: _______________
Identifying Substances Using Density – Marking Key
Observations
/8
Analysis Graph
/8
Questions
/14
TOTAL MARK
/30
Comments:
SNC1P- Chemistry
Mr. Scott