IMPORTANT CHEM 162 CONCEPTS
Rules for Assigning Oxidation States - CORRECT ANSWER-1. Elements in their
elemental form are in the zero oxidation state.
2. Group 1 metals are +1 and Group 2 metals are +2.
3. Hydrogen is +1 except when bonded to a metal only (then it's -1)
4. Transition elements must be determined from anion's charge (except Al = +3,
Zn = +2, Cd = +2, Ag = +1)
5. The most electronegative elements get their typical oxidation state.
6. The last element not assigned balances the charge of the compound/ion.
Rules for Balancing Redox Reactions (Half Rxn Method) - CORRECT
ANSWER-IF ACID
1. Split into half reactions
2. Balance all elements EXCEPT oxygen and hydrogen
3. Balance oxygen by adding H2O
4. Balance hydrogen by adding H+
5. Balance charge by adding electrons
6. Multiply half reactions by factors to make number of electrons the same
7. Combine half reactions, canceling anything that shows up on both sides
IF BASE
8. Add same number of OH- to both sides as H+ present
9. Cancel any excess H2O if necessary
Zero Order - CORRECT ANSWER-Rate Law: k[A]^0
Integrated Rate Law: [A]t = [A]0 - kt
Units: M^1 s^-1
First Order - CORRECT ANSWER-Rate Law: k[A]^1
Integrated Rate Law: ln[A]t = ln[A]0 - kt
Units: s^-1
Rules for Assigning Oxidation States - CORRECT ANSWER-1. Elements in their
elemental form are in the zero oxidation state.
2. Group 1 metals are +1 and Group 2 metals are +2.
3. Hydrogen is +1 except when bonded to a metal only (then it's -1)
4. Transition elements must be determined from anion's charge (except Al = +3,
Zn = +2, Cd = +2, Ag = +1)
5. The most electronegative elements get their typical oxidation state.
6. The last element not assigned balances the charge of the compound/ion.
Rules for Balancing Redox Reactions (Half Rxn Method) - CORRECT
ANSWER-IF ACID
1. Split into half reactions
2. Balance all elements EXCEPT oxygen and hydrogen
3. Balance oxygen by adding H2O
4. Balance hydrogen by adding H+
5. Balance charge by adding electrons
6. Multiply half reactions by factors to make number of electrons the same
7. Combine half reactions, canceling anything that shows up on both sides
IF BASE
8. Add same number of OH- to both sides as H+ present
9. Cancel any excess H2O if necessary
Zero Order - CORRECT ANSWER-Rate Law: k[A]^0
Integrated Rate Law: [A]t = [A]0 - kt
Units: M^1 s^-1
First Order - CORRECT ANSWER-Rate Law: k[A]^1
Integrated Rate Law: ln[A]t = ln[A]0 - kt
Units: s^-1
