First Something Familiar

What do the following items have in common?

What common traits did you notice?

Now, Something Not Familiar

What do the following items have in common?

Use your note-taking template to list some common traits for the examples you see

32 grams of Sulfur

12 grams of carbon

Examples of the Mole

201 grams of Mercury

55.8 grams of Iron

Chemists use the idea of the mole when comparing the number of particles of different substances.

How many atoms are there in 12 g of carbon (one mole)?

This is the number of atoms in 12 g of carbon or one mole of particles.

It is called the Avogadro constant.

If you started counting 220 million carbon atoms per second 85 million years ago,you might just have finished counting a mole of them about now.

12 g of carbon contains 1 mole of carbon atoms, or 1 mol for short.

How many moles of sulphur atoms are there in 32 g of sulphur?

Notice that the mass of one mole is the equal to the relative atomic massin grams.

So, how many moles of iron atoms are there in 56 g of iron?

If you know the Ar or Mr of a substance, you can easily work out the massof one mole of that substance.

This is the relationship between moles, grams and molar mass.

This ‘magic triangle’ might help you in calculations.

What is the amount in moles of carbon atoms in 6 g of carbon?

The mass is grams in 6.

The Ar of carbon is 12 so its molar mass is 12 g mol-1.

There are 0.5 mol of carbon atoms in 6 g of carbon.

This is the relationship between moles, grams and molar mass.

This ‘magic triangle’ might help you in calculations.

What is the mass of 2 moles of calcium carbonate, CaCO3?

The Mr of calcium carbonate is 100 so its molar mass is 100 g mol-1.

The amount in moles is 2.

2 moles of calcium carbonate, CaCO3, have a mass of 200 g.