UNDERSTANDING THE MOLE

In chemistry, the fundamental unit of matter is the mole.  You must understand and be able to use the mole concept.  In this activity, you will practice determining the number of moles, number of grams, number of atoms, and number of molecules of different substances.  Make sure that you show your work!  (There is room to the right side of each table for you to show your work.)

STATION #1:  AVERAGE MASS OF PLASTIC BAGS
Determine and record the mass of three different plastic bags with labels.
Calculate the average mass of one plastic bag.

 Bag #1 _______________ grams Bag #2 _______________ grams Bag #3 _______________ grams Average _______________ grams

STATION #2:  COPPER
Determine and record the mass of the plastic bag with the copper.  What is the mass of the copper in the bag?
~ Calculate the number of moles of copper in the bag.
~ Calculate the number of atoms of copper in the bag.

 Mass of bag with copper _______________ grams Mass of copper _______________ grams Moles of copper _______________ moles Atoms of copper _______________ atoms

STATION #3:  BAKING SODA (SODIUM BICARBONATE – NaHCO3)

Determine and record the mass of the plastic bag with baking soda.  What is the mass of the baking soda in the bag?

~ Calculate the number of moles of baking soda in the bag.

~ Calculate the number of molecules of baking soda in the bag.

 Mass of bag with baking soda _______________ grams Mass of baking soda _______________ grams Moles of baking soda _______________ moles Molecules of baking soda _______________ molecules

STATION #4:  WATER

Fill a clean, unused paper cup about two-thirds full of water.  Determine and record the mass of the paper cup and water.  Take a drink of the water.  Determine and record the mass of the cup and the water left in it.  Throw the used cup in the trash.

~ How many moles of water did you drink?

~ How many molecules of water did you drink?

 Mass of cup & water before drinking _______________ grams Mass of cup & water after drinking _______________ grams Mass of water _______________ grams Moles of water _______________ moles Molecules of water _______________ molecules

STATION #5:  CALCIUM SULFATE (CaSO4)

Determine and record the mass of the plastic bag with calcium sulfate.

~ How many moles of calcium sulfate are in the bag?

~ How many moles of oxygen are contained in the calcium sulfate in the bag? *

 Mass of bag and calcium sulfate _______________ grams Mass of calcium sulfate _______________ grams Moles of calcium sulfate _______________ moles Moles of oxygen * _______________ moles

STATION #6:  TABLE SALT (SODIUM CHLORIDE – NaCl)

Record the number of moles of sodium chloride given on the label of the plastic bag with the salt.

Determine and record the mass of the plastic bag with salt in it.

~ How many moles of salt are in the bag?

~ What is your percent error?  (Assume that the number given on the bag is the “accepted value”.)

 Accepted # of moles of NaCl in bag _______________ moles Mass of bag and salt _______________ grams Mass of salt _______________ grams Moles of salt _______________ moles Percent error _______________ %

STATION #7:  IRON

Record the number of atoms of iron given on the label of the plastic bag with the iron.

Determine and record the mass of the plastic bag with iron in it.

~ How many moles of iron are in the bag?

~ How many atoms of iron are in the bag?

~ What is your percent error?  (Assume that the number given on the bag is the “accepted value”.)

 Accepted # of atoms of Fe in bag _______________ atoms Mass of bag and iron _______________ grams Mass of iron _______________ grams Moles of iron _______________ moles Atoms of iron _______________ atoms Percent error _______________ %