L.5 Balancing Equations

Question 1

OIL RIG

Answer 1

OXIDATION IS LOSS OF ELECTRONS

REDUCTION IS GAIN OF ELECTRONS

Question 2

Definition of…

Oxidizing agent

Reducing agent

Answer 2

Oxidizing agent = reduced itself, commonly have oxygen or other similar electronegative elements.

Reducing agent = oxidized itself, often contain metal ions or hydrides.

Question 3

Four steps to assigning oxidation numbers

Answer 3

1. Atoms in elemental state = 0
2. Atoms in monotonic (exactly one atom Cl-) = oxidation # equal to their charge

3.

F = -1

H = +1 (paired w/less electronegative element = -1)

0 = -2 (unless in peroxide or more electronegative atom = -1)

4. Assign oxidation numbers to the rest of the atoms

OTHER STEPS TO REMEMBER

Group 1 = +1

Group 2 = +2

Group 17 = -1 (unless combined with stronger ectronegative element) Group 16 = -2

Group 15 = -3

Question 4

8 Rules for balancing REDOX Reactions

Answer 4

1. write 1/2 rxns
2. balance atoms other than oxygen and hydrogen
3. balance oxygen by adding h2o
4. balance hydrogens by adding H+
5. balance charges by adding electrons
6. make # of electrons equal ll for 1/2 reactions
7. add 1/2 reactions and cancel
8. in basic solution add OH to balance H+

Question 5

Definition of complete ionic equation

Answer 5

Equations that accounts for all of the ions present in a reaction, you have to split all aqueous compounds into their relevant ions, keeping solids intact.

Question 6

Definition of Net Ionic Equations

Answer 6

An Equation that has only ions that participate in the reactions, eliminate spectator ions

Question 7

Decomposition Rxn

(NH₄)2Cr₂O₇ –> N_{2 +} Cr₂O₃ + 4 H₂O

Answer 7

Reactant Decomposes AB —–> A + B

Hydrolysis of water = 2 H2O –> O2 + 2H2

-3. +1. +6. -2 0. +3. -2 +1 -2

(NH₄)2Cr₂O₇ –> N_{2 +} Cr₂O₃ + 4 H₂O

Question 8

Combustion Reaction

CH_{4 +} 2O₂ —–> CO₂ + 2H₂O

Answer 8

A fuel (usually a hydrocarbon ) mixed w/oxidant (usually oxygen) to form carbon dioxide and water.

-4 +1. 0 +4 -2 +1. -2

CH_{4 +} 2O₂ —–> CO₂ + 2H₂​O

Question 9

Combination Reaction

H ₂ + F₂ ——-> 2HF

Answer 9

0. 0 +1. -1

H ₂ + F₂ ——-> 2HF

Question 10

Disproportionation Reaction

2H₂O_{2 —–>} 2H₂O. + O₂

Answer 10

A redox reaction in which one element is both oxidized and reduced

+1 -1 +1. -2 0

2H₂O_{2 —–>} 2H₂O. + O₂

Question 11

Single and Double Displacement

Answer 11

Single = AB + C —–> AC + B

Double = AB + CD —–> AC + BD

Question 12

Oxidizing Agents

Answer 12

O_{2 oxygen}

H₂O_{2 hydrogen peroxide}

Halogens F₂ Cl₂ Br₂ I₂

H₂SO_{4 dihydrogen sulfate or sulfuric acid}

HNO_{3 hydrogen nitrate or nitric acid}

NaClO _{sodium hypoclorite}

KMnO_{4 Potassium permanganate}

CrO_{3 Chromium Trioxide}

Na₂Cr₂O_{7 Sodium Dichromate}

PCC (PyridiniumChloromate)

NAD+ and FADH

Question 13

Reducing Agents

Answer 13

CO _{Carbon Monoxide}

C _Carbon

B₂H_{6 Diborane}

Sn²⁺ and other pure metals

Hydrazine (N₂H₄)

Zn(Hg)

Lindlar’s Catalyst

NaBH_{4 sodium borohydride}

LiAlH_{4 Lithium aluminohydride}

NADH and FADH₂

Question 14

Nomenclature of Ionic Compounds

For elements (usually metals) that can form more than 1 positive ion

Answer 14

Fe2+ Iron II

Fe3+ Iron III

Cu+ Copper I

Cu+2 Copper II

Question 15

Nomenclature of Ionic Compounds

Ending in -ous or -ic

Answer 15

Fe2+ Ferrous

Fe3+ Ferric

Cu+ Cuprous

Cu2+ Cupric

Question 16

Monoatomic Anions,

dropping the ending of the element & adding -ide

Answer 16

H- Hydried

F- Fluoride

O^2- Oxide

S^2- Sulfide

N^3- Nitride

P^3- Phosphide

Question 17

Polyatomic anions that contain oxygen are called oxyanions

Elements form two oxyanions

1. more oxygens -**ite
2. fewer oxygens -ate

Answer 17

NO_2^- Nitrite

NO_3^- Nitrate

SO_3^2- Sulfite

SO_4^2- Sulfate

Question 18

Chlorine oxyanions

Answer 18

ClO^- Hypochlorite

ClO₂^- Chlorite

ClO₃^- Chlorate

ClO₄^- Perchlorate

Question 19

HCO₃^-

HSO₄^-

H₂PO_4^-

Answer 19

Hydrogen Carbonate or Bicarbonate

Hydrogen Sulfate or Bisulfate

Dihydrogen Phosphate

Question 20

NH₄⁺

C₂H₃O₂^-

CN^-

MnO₄^-

SCN^-

CrO₄^2-

Cr₂O₇^2-

BO₃^3-

Answer 20

Ammonium

Acetate

Cyanide

Permanganate

Thiocyanate

Chromate

Dichromate

Borate

Question 21

Solutes that are able to carry currents are called…

Answer 21

Electrolytes

They contain equivalents of ions from molecules that dissociate in solution. The strength of the electrolyte depends on its degree of dissociation or solvation.

Question 22

Neutralization reaction

Answer 22

When an acid combines with a base to form a salt