SCH3U
Name:_____________
Finding Mass, Moles and Particles
Introduction
In this lab you will use an electronic balance to accurately determine the
mass, number of moles, and number of particles for a variety of substances.
Purpose (2 marks, C)
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Materials
Plastic bag
Balance
samples NUMBERED 1,2,3…
Procedure
1. Give Table 1 an appropriate title.
2. Take the mass of an empty plastic bag and record all significant digits in Table 1. Assume a constant mass
for all plastic bags.
3. Look at the label on your sample and record the name and chemical formula in Table 1.
4. Take the mass of the sample + bag and record it in Table 1.
5. Repeat this procedure for any four samples.
Observations
Table 1._______________________________________________________________________(1 mark, C)
Sample Number
Marks
Sample Name
Chemical Formula
/4 K
Type of Particle
Mass of Sample + Bag
(g)
Mass of Bag
(g)
Calculations
Complete the chart.
Sample Number
/4 I
Marks
Mass of Sample
(g)
Molar Mass
(g/mol)
Number of Moles
(mol)
Number of Particles
/4 I
/4 I
/4 I
/4 I
Revised Oct 2015
SCH3U
Name:_____________
Sample Calculations
Show a sample calculation for each of the quantities you calculated. You only need to show the
calculations for one sample since the rest of the calculations will follow the same steps.
Include ALL
units and steps!
a) Mass of Sample (2 marks, I)
b) Molar Mass (2 marks, I)
c) Number of Moles (2 marks, I)
d) Number of Particles (2 marks, I)
Discussion Questions
1. Describe 2 sources of error in this experiment and explain how each of the 2 sources of error
affects your experimental results.(Does it make your final values higher or lower than
expected?) (4 marks, A)
2. Why is it important to be able to convert between mass and number of particles in a factory
setting. Use a specific real life example (or scenario) to explain. (2 marks)
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Revised Oct 2015
SCH3U
Name:_____________
Solving the Element Mystery
Introduction
In this lab you will use an electronic balance to accurately determine the mass of different mystery
elements. You will use the mass and the number of moles, along with some physical properties to
correctly identify the unknown elements.
Purpose (2 marks, C)
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Materials
Petri Dish
Balance
samples LETTERED A,B,C…
Procedure
1. Give Table 2 an appropriate title.
2. Take the mass of Petri Dish and record it in Table 2. Assume a constant mass for all Petri Dishes.
3. Look at the label on your sample and record the number of moles in the Petri Dish in Table 2.
4. Take the mass of the sample and Petri Dish and record it in Table 2.
5. Repeat this procedure for any five samples.
Observations
Table 1._____________________________________________________________________(1 mark, C)
Element Sample
Marks
Physical Description
/5 I
Table 2.______________________________________________________________________
Element Sample
Marks
# of Moles (mol)
Mass of Sample + Petri
Dish
(g)
Mass of Petri Dish
(g)
Calculations
Complete the chart.
Element Sample
/4 I
Mass of Sample Only
(g)
Molar Mass
(g/mol)
/4 I
/4 I
Revised Oct 2015
SCH3U
Name:_____________
Sample Calculations
Show a sample calculation for the mass of the sample and the molar mass.
a) Mass of Sample (2 marks, I)
a) Molar Mass (2 marks, I)
Discussion Questions
Use your qualitative and quantitative observations to explain how you knew what each element was.
You may need to do some research to confirm your answer. (10 marks, A)
Revised Oct 2015