the mole what a fun concept. what is a mole? a burrowing critter? a skin pigmentation? a word that...
TRANSCRIPT
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