I. 3.1 METRIC UNITS
II. 3.2 DENSITY
III. 3.3 EMPIRICAL FORMULAS
A. Empirical formula – the lowest ratio of atoms in a molecule
IV. 3.4: FORMULA AND MOLECULAR WEIGHT
A. Formula weight – sum of the atomic weights of all the atoms in the molcule
B. Atomic mass unit – 1 amu = 1/12 the mass of a carbon-12 atom
V. 3.5: THE MOLE
A. Avogadro’s number = 6.02 * 1023 entities
VI. 3.6: PERCENTAGE COMPOSITION BY MASS
VII. 3.7: CONCENTRATION
A. Molarity = moles/(volume
[L] solution)
B. Molality = moles/(weight [kg] of solvent)
C. Mole fraction – way to express a concentration when more than one solute is present
VIII. 3.8: CHEMICAL EQUATIONS AND STOICHIOMETRIC COEFFICIENTS
IX. 3.9: STOICHIOMETRIC RELATIONSHIPS IN BALANCED REACTIONS
X. 3.10: THE LIMITING REAGENT
XI. 3.11: SOME NOTATION USED IN CHEMICAL EQUATIONS
XII. 3.12: OXIDATION STATES
A. Meant to indicate how the atom’s “ownership” of its valence electrons changes when it forms a compound
B. Rules:
1. The oxidation state of any element in its standard state is 0
2. The sum of the oxidation states of the atoms in a neutral molecule must be 0, and the sum of the oxidation states of the atoms in an ion must always equal the ion’s charge
3. Group 1 metals have a +1 oxidation state
4. Group 2 metals have a +2 oxidation state
5. Hydrogen has a +1 oxidation state when bonded to something more electronegative than C
6. Hydrogen has a -1 oxidation state when bonded to something less electronegative than C
7. Hydrogen has 0 oxidation state when bonded to C
8. Oxygen has -2 oxidation state
9. The rest of the halogens have a -1 oxidation state and atoms of the O family have a -2 oxidation state
(a) **In peroxides, O has -1 oxidation state
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B. Molality = moles/(weight [kg] of solvent)
C. Mole fraction – way to express a concentration when more than one solute is present
VIII. 3.8: CHEMICAL EQUATIONS AND STOICHIOMETRIC COEFFICIENTS
IX. 3.9: STOICHIOMETRIC RELATIONSHIPS IN BALANCED REACTIONS
X. 3.10: THE LIMITING REAGENT
XI. 3.11: SOME NOTATION USED IN CHEMICAL EQUATIONS
XII. 3.12: OXIDATION STATES
A. Meant to indicate how the atom’s “ownership” of its valence electrons changes when it forms a compound
B. Rules:
1. The oxidation state of any element in its standard state is 0
2. The sum of the oxidation states of the atoms in a neutral molecule must be 0, and the sum of the oxidation states of the atoms in an ion must always equal the ion’s charge
3. Group 1 metals have a +1 oxidation state
4. Group 2 metals have a +2 oxidation state
5. Hydrogen has a +1 oxidation state when bonded to something more electronegative than C
6. Hydrogen has a -1 oxidation state when bonded to something less electronegative than C
7. Hydrogen has 0 oxidation state when bonded to C
8. Oxygen has -2 oxidation state
9. The rest of the halogens have a -1 oxidation state and atoms of the O family have a -2 oxidation state
(a) **In peroxides, O has -1 oxidation state
