Name:
Date: _____________________________
Chemistry: Molar Conversions Lab Activity
As always: Turn in YOUR OWN ANSWER SHEET!!!
You will be working with various items at your lab stations to practice molar conversions. These conversions
will involve Avogrado’s Number and mass. You will need a scale (remember to 0 out between
measurements) and a calculator to complete this lab.
Use this sample equation and your notes from 2/7 (Tuesday) as a guide:
Part 1
Take a small sheet of aluminum foil.
1.
Is this sample one mole of aluminum? If not, how would you calculate the number of moles in this
sample? (Show your work)
2.
Approximately how many atoms of aluminum are in this sample?
Part 2 - DO NOT EAT THE OREOS until you are finished with Part 8!
1.
Using a piece of weigh paper, measure and record the mass of a regular Oreo cookie.
Carefully open the plain Oreo cookie and scrape off the cream.
2.
Find the mass of the cream and the mass of the Oreo cookie sides. Discard the Oreo.
3.
Calculate the percent composition of the cream vs. the total mass of the regular Oreo.
Mass of the cream (g) / total mass(g)=
4.
Using a piece of weigh paper, measure and record the mass of a "Doublestuff" Oreo cookie.
Oreos continued…..
Carefully open the Doublestuff Oreo cookie and scrape off the cream.
5.
Find the mass of the cream and the mass of the Doublestuff cookie sides. Discard the
Doublestuff Oreo.
6.
Calculate the percent composition of the cream vs. the total mass of the Doublestuff Oreo.
7.
Does a Doublestuff Oreo really have twice the cream of a plain Oreo cookie? Explain.
Part 3
Take a plastic drinking cups. Fill one cup halfway full of water.
8.
Measure and record the mass of the cup and water.
Pour out the water.
9.
Measure and record the mass of the empty cup after you poured out the water in the cup.
10.
How many molecules of water did you pour out?
Part 4
Read the label on the Snickers Bag. DO NOT OPEN your Snickers bar.
11.
How many grams of sucrose (C12H22O11) are there in one bar?
12.
How many molecules of sucrose are there in one bar?
C12 = 12 X ____ = ______ amu
H22 = 22 X ____ = ______ amu
----Then add the amu’s and convert to molecules
O11= 11 X ____ = ______ amu
13.
What is the percent composition (mass of each atom/total mass) of each of the elements that make up
sucrose?
Part 5
Take a piece of chewing gum and weigh paper.
14.
Using a piece of weigh paper, measure and record the mass of an unwrapped piece of bubble gum.
DO NOT PLACE THE GUM DIRECTLY ON THE BALANCE.
Chew the gum until all the sugar is dissolved in your mouth (you may wish to come back to this later).
15.
Measure and record the mass of the chewed gum.
16.
What is the mass of the sugar in the gum?
17.
How many molecules of sugar (C12H22O11) did you dissolve?
After you finish your calculations,
turn your answer sheet in by the end of the period.
As always: Turn in YOUR OWN ANSWER SHEET!!!
Station G