MGCCC, Perk Learning Lab

TLM

1 mol = 6.022 x 10²³ particles

1 mol = 6.022 x 10²³ atoms (use with molecular compounds)

1 mol = 6.022 x 10²³ formula units (used with ionic compounds)

1 mol = 6.022 x 10²³ molecules

Atom- the smallest particle of an element that maintains its chemical identity through all chemical and physical changes.

Molecule- the smallest particle of an element or compound that can have a stable independent existence

Compound- a substance composed of two or more elements in fixed proportions

Element- a substance that cannot be decomposed into simpler substances by chemical means; composed of only one type of atom

Formula Unit- the smallest repeating unit of a substance; for non-ionic substances, the molecule.

Ion- an atom or group of atoms that carries an electrical charge; unequal # of protons and electrons

Molecular Compound- a compound that does not contain ions

Ionic Compound- a compound that is composed of cations and anions

MASS OF ONE MOLE OF ATOMS OF ELEMENTS

Element	# of Atoms in formula	Sample	Contains
Carbon: C	1 atom for each molecule	12.001g C	6.022 x 10^23 C atoms or 1 mol of C atoms 6.022 x 10^23 C molecules
Hydrogen: H2	2 atoms for each molecule	1.0079g H2	6.022 x 10^23 H atoms or 1 mol of H atoms 3.011 x 10^23 H2 molecules
Sulfur: S8	8 atoms for each molecule	32.066g S8	6.022 x 10^23 S atoms or 1 mol of S atoms 0.75 x 10^23 S8 molecules

MASS OF ONE MOLE OF MOLECULAR SUBSTANCES

Substance	Molecular Wt	Sample	# of Atoms in formula	Contains
Hydrogen	2.016	2.016g H2	2 H	6.022 x 10^23 molecules or 1 mol of H2 molecules 2 * 6.022 x 10^23 = 1.2044 x 10^24 atoms of H or 2 mol of H atoms
Methane	16.04	16.04g CH4	1 C, 4 H	6.022 x 10^23 CH4 molecules or 1 mol of CH4 molecules 6.022 x 10^23 C atoms or 1 mol of C atoms 4 * 6.022 x 10^23 = 2.4088 x 10 ^23 H atoms or 4 mol of H atoms

MASS OF ONE MOLE OF IONIC COMPOUNDS

Compound	Formula Wt	Sample with a Mass of 1 mol	# of Atoms in formula	Contains
Sodium Chloride	58.44	58.44 g NaCl	1 Na, 1 Cl	6.022 x 10^23 Na^+ions or 1 mol of Na^+ ions 6.022 x 10^23 Cl^- ions or 1 mol of Cl^- ions
Aluminum Sulfate	342.1	342.1g Al2(SO4)3	2 Al, 3 (SO4)	2 * 6.022 x 10^23= 1.2044 x 10^24 Al^+3 ions or 2 moles of Al^+3 ions 3 * 6.022 x 10^23= 1.8066 x 10^24 SO4^-2 ions or 3 moles of SO4^–2 ions

MGCCC, Perk Learning Lab

TLM

CONVERTING ATOMS, MOLECULES & MOLES

1. How many moles of atoms does 355.7 g of gold contain?

2. Calculate the mass of one carbon atom in grams.

3. How many (a) moles of Cl₂ (b) Cl₂ molecules and (c) Cl atoms are contained in 45 g of Chlorine gas (Cl₂)?

4. Calculate the number of (a) hydrogen, (b) oxygen and (c) sulfur atoms in 63g of sulfuric acid (H₂SO₄)

5. A sample of metal contains 2.516 x 10²³ atoms and has a mass of 82.29 grams. (a)How many moles of metal atoms are present in the sample? (b) What is the metal?

6. How many moles of O are in 6 moles of O₃?

ANSWERS ON BACK

ANSWERS

1. 355.7g Au * 1 mol Au atoms = 1.805 moles of Au atoms

196.97 g Au

2. 12 g C * 1 mol C atoms = 1.99 x 10^-23 g C/ C atoms

1 mol C atoms 6.022 x 10 ²³ C atoms

3. a. 45g Cl₂ * 1 mol Cl₂ = 0.635 mol Cl₂

70.906 g Cl₂

_b. 0.635 mol Cl₂ * 6.022 x 10²³ molecules = 3.82 x 10²³ Cl₂ molecules

1 mol Cl₂

c. 3.82 x 10²³ Cl₂ molecules * 2 Cl atoms = 7.64 x 10²³ Cl atoms

1 Cl₂ molecule

4. a. 63 g H₂SO₄ * 1 mol H₂SO₄ * 6.022 x 10²³ molecules * 2 H atoms = 7.7 x 10²³ H atoms

98 g H₂SO₄ 1 mol H₂SO₄ 1 H₂SO₄ molecule

b. 63 g H₂SO₄ * 1 mol H₂SO₄ * 6.022 x 10²³ molecules * 1 S atom = 3.87 x 10²³ S atoms

98 g H₂SO₄ 1 mol H₂SO₄ 1 H₂SO₄ molecule

c. 63 g H₂SO₄ * 1 mol H₂SO₄ * 6.022 x 10²³ molecules * 4 O atoms = 1.54 x 10²⁴ O atoms

98 g H₂SO₄ 1 mol H₂SO₄ 1 H₂SO₄ molecule

5. a. 2.516 x 10²³ atoms * 1 mol = 0.4178 mol of metal

6.022 x 10²³ atoms

b. 82.29 g = 196.96 g/mol , Au (gold) is the metal

0.4178 mol

6. 6 mol O₃ * 3 mol O = 18 mol O

1 mol O₃