Moles

Sig fig rules?

Significant- all non-zeros, zeros at the end if there is a decimal, and zeros between non-zeros.

Not significant- zeros at the end (no decimal) and placeholder zeros (front of a number)

If you owned a candy store and get an order of 10000 jelly beans, would it be easier to count by hand or measure by weight?

By weight

What is a mole?

A mole is a certain number of particles. It is used so that the amount of particles can be measured easily.

What is Avogadro’s number

6.022 × 10²³

What can be a particle?

Atoms, molecules (covalent), or formula units (ionic)

How do you know the mass of the mole?

It is the atomic mass on the periodic table

How do you convert moles to grams?

Multiply the number of moles by the amount of grams per mole ex:

2.000 mol C x 12.01g/1mol C= 24.02 g C

How do you convert from grams to moles?

Divide the number of grams you have by the number of grams in 1 mol. Ex:

73.45 g C x 1mol/12.01g C= 6.116 mol C

What is molarr mass?

The mass of 1 mol of a substance. Units are g/mol. Can be found on the periodic table.

What is the molar mass of CaCl₂?

Ca= 40.078 g/mol Cl= 35.453g/ mol

35.453 × 2= 70.906

70.906+40.078= 110.984g/mol CaCl₂