THE MOLEWhat a fun concept

WHAT IS A MOLE?

A burrowing critter? A skin pigmentation? A word that evokes an enormous number?

1 mole of any substance equals 6.02 x 1023

representative particles of that substance 6.02 x 1023

is known as Avogadro’s number

WHAT IS A REPRESENTATIVE PARTICLE?

It depends on what the substance is What can a substance be?

Element Anything but the BrINClHOF elements which are

diatomic molecules in nature Molecular compound

Made of two or more nonmetals…includes BrINClHOF elements with their subscripts of 2

Ionic compound Made of a metal and a nonmetal or contains a

polyatomic ion

A HANDY LITTLE CHART

Substance Representative Particle (rp)

Smaller bits

Element Atom

Molecular Compound

Molecule Atoms

Ionic Compound Formula Unit Ions

SO, HERE WE GO…

1 mol of Fe contains 6.02 x 1023 atoms of Fe

1 mol of Br2 contains 6.02 x 1023 molecules of Br2

1 mol of NaCl contains 6.02 x 1023 formula units

of NaCl

1 mol of SO3 contains 6.02 x 1023 molecules of

SO3

1 mol of Na2O contains 6.02 x 1023 formula units

of Na2O

AND WE MAKE THAT INFO USEFUL BY WRITING IT AS… 1 mol Fe 6.02 x 1023

atoms Fe

1 mol of Br2 6.02 x 1023

molec Br2

1 mol of NaCl 6.02 x 1023

fu NaCl

1 mol of SO3

6.02 x 1023 molec SO3

1 mol Na2O 6.02 x 1023

fu Na2O

OR WE CAN FLIP THEM TO GET… 6.02 x 1023

atoms Fe 1 mol Fe 6.02 x 1023

molec Br2

1 mol of Br2

6.02 x 1023 fu NaCl

1 mol of NaCl

6.02 x 1023 molec SO3

1 mol of SO3

6.02 x 1023

fu Na2O 1 mol Na2O

SMALLER BITS?

Only for molecules and formula units 1 molec Br2 has 2 atoms of Br

1 fu NaCl has 1 Na1+ ion and 1 Cl1- ion

1 molec SO3 has 1 S atom and 3 O atoms

1 fu Na2O has 2 Na1+ ions and 1 O2- ion

MOLAR MASS

The mass of one mole of a substance Use average atomic masses from the periodic

table and round their masses to the hundredths place for consistency

Unit is g/mol

1 mol Fe = 55.85 g Fe …55.85 g Fe = 1 mol Fe

1 mol Fe or 55.85 g Fe55.85 g Fe 1 mol Fe

MOLAR MASS OF A COMPOUND

For a compound, you must calculate the molar mass

Molar Mass of Br2

Br---2 x 79.90 = 159.80 g/mol

1 mol Br2 or 159.80 g Br2

159.80 g Br2 1 mol Br2

MOLAR MASS OF A COMPOUND

Molar Mass of NaClNa---1 x 22.99 = 22.99Cl--- 1 x 35.45 = 35.45

58.44 g/mol

1 mol NaCl or 58.44 g NaCl58.44 g NaCl 1 mol NaCl

MOLAR MASS OF A COMPOUND

Molar Mass of SO3

S---1 x 32.06 = 32.06O---3 x 16.00 = 48.00

80.06 g/mol

1 mol SO3 or 80.06g SO3

80.06 g SO3 1 mol SO3

MOLAR MASS OF A COMPOUND

Molar Mass of Na2ONa---2 x 22.99 = 45.98O--- 1 x 16.00 = 16.00

61.98 g/mol

1 mol Na2O or 61.98 g Na2O

61.98 g Na2O 1 mol Na2O

MOLAR MASS OF A COMPOUND

Molar Mass of Ca(OH)2

Ca---1 x 40.08 = 40.08O--- 2 x 16.00 = 32.00H--- 2 x 1.01 = 2.02

74.10 g/mol

1 mol Ca(OH)2 or 74.10 g Ca(OH)2

74.10 g Ca(OH)2 1 mol Ca(OH)2

MOLAR MASS OF A COMPOUND

Molar Mass of Mg(C2H3O2)2

Mg---1 x 40.08 = 24.31C--- 4 x 12.00 = 48.00H--- 6 x 1.01 = 6.06O--- 4 x 16.00 = 64.00

142.37 g/mol

1 mol Mg(C2H3O2)2 or 142.37 g Mg(C2H3O2)2

142.37 g Mg(C2H3O2)2 1 mol Mg(C2H3O2)2

ANOTHER HANDY CHART

1 mol

AND NOW, YOU PUT IT ALL TOGETHER

SO, HAVE FUN

PRACTICING