Writing Net Ionic Equations

Review UCEHB Double Replacement (UCEHB pg. 47; 55) Double Replacement (UCEHB pg. 47; 55) Redox / Single Replacement (UCEHB pg. 45;63) Redox / Single Replacement (UCEHB pg. 45;63) Composition/Decomposition (UCEHB pg. 75) Composition/Decomposition (UCEHB pg. 75) Complex Ions (UCEHB pg. 23;79) Complex Ions (UCEHB pg. 23;79) Combustion (UCEHB pg. 29) Combustion (UCEHB pg. 29)

Double Replacement Reactions Identify the type: Identify the type: –Acid / Base: look for terms like excess;equal number of moles; equal volumes of __M. Think about the types of acids/bases; conjugate acid/base pairs. NH 3 + HF NH F – NH 3 + HF NH F – –Precipitation: memorize the solubility rules. Ba 2+ + SO 4 2- BaSO 4 Ba 2+ + SO 4 2- BaSO 4 –Both 2 H + + SO Ca(OH) 2 CaSO HOH 2 H + + SO Ca(OH) 2 CaSO HOH

Double Replacement Reactions –Reactants frequently in aqueous solutions. –Produce molecular compound such as water; gas; or precipitate. –Know how these gases CO 2 ; SO 2 ; NH 3 ; and H 2 S are formed. –Solubility rules help tell: »Which are ions in solution. »Identify the precipitate.

Redox / Single Replacement Redox Redox Know: Know: –Common oxidizing and reducing agents and the products formed. (UCEHB pg.68) –Use of key terms: acidified MnO 4 - ; H 2 O 2 ; Cr 2 O 7 2- ; HNO 3 MnO 4 - ; H 2 O 2 ; Cr 2 O 7 2- ; HNO 3 –Elements with multiple oxidation states Sn 2+ ; Sn 4+ ; Cr 2+ ; Cr 3+ ; Cr 6+ ; I - ; IO - ; IO 2 - ; Sn 2+ ; Sn 4+ ; Cr 2+ ; Cr 3+ ; Cr 6+ ; I - ; IO - ; IO 2 - ; O(-1 or -2) O(-1 or -2) –Acidic and Basic conditions 4 MnO H H 2 O 2 4 Mn O H 2 O 4 MnO H H 2 O 2 4 Mn O H 2 O

Redox / Single Replacement Single Replacement Single Replacement Like replaces like Like replaces like –Metals replace metals. 2Na (s) + 2H 2 O (l) 2 NaOH (aq) + H 2(g) 2Na + 2HOH 2 NaOH + H 2 2 Na (s) + 2H 2 O (l) 2Na + (aq) + 2OH - (aq) + H 2(g) 2 Na (s) + 2H 2 O (l) 2Na + (aq) + 2OH - (aq) + H 2(g) –Nonmetals replace nonmetals. Cl 2 (g) + 2 KI (aq) 2 K + (aq) + 2 Cl - (aq) + I 2(s) Cl 2 (g) + 2 KI (aq) 2 K + (aq) + 2 Cl - (aq) + I 2(s) Cl 2 (g) + 2 KI (aq) 2 K + (aq) + 2 Cl - (aq) + I 2 (s) Must be in aqueous solution to dissociate. Strong bases in aqueous solution 100% dissociation.

Combustion Reaction of a hydrocarbon/alcohol or other organic molecule with oxygen gas to produce carbon dioxide and water. Reaction of a hydrocarbon/alcohol or other organic molecule with oxygen gas to produce carbon dioxide and water. –Oxygen is a reactant. C 3 H 8 + 5O 2 3CO 2 + 4H 2 O C 3 H 8 + 5O 2 3CO 2 + 4H 2 O CH 3 CH 2 OH + 3O 2 2CO 2 + 3H 2 O CH 3 CH 2 OH + 3O 2 2CO 2 + 3H 2 O

Decomposition/Composition Decomposition: Decomposition: –has only one reactant and it breaks up into elements and /or compounds MgCO 3 MgO + CO 2 MgCO 3 MgO + CO 2 Ba(OH) 2 BaO + H 2 O Ba(OH) 2 BaO + H 2 O 2Al 2 O 3 4Al + 3O 2 2Al 2 O 3 4Al + 3O 2

Decomposition/Composition Composition: Composition: – has two reactants that combine into one product: S O 2 8 SO 2 S O 2 8 SO 2 –Nonmetal oxides plus water makes acid: acid: SO 3 + H 2 O 2 H + + SO 4 2- SO 3 + H 2 O 2 H + + SO 4 2- –Metal oxides plus water makes base: CaO + H 2 O Ca(OH) 2 CaO + H 2 O Ca(OH) 2

Complex Ions Particles that generally combine with excess ammonia or hydroxides to form complex ions with a charge Particles that generally combine with excess ammonia or hydroxides to form complex ions with a charge Cu NH 3 Cu(NH 3 ) 4 2+ Cu NH 3 Cu(NH 3 ) 4 2+ Al OH - Al(OH) 4 - Al OH - Al(OH) 4 - AgCl + 2 NH 3 Ag(NH 3 ) Cl - AgCl + 2 NH 3 Ag(NH 3 ) Cl - having the correct ligand number is not required but being consistent with number and charge is important having the correct ligand number is not required but being consistent with number and charge is important

Review Identify type of reaction. Identify type of reaction. –Remember: »What drives each type of reaction. »Conditions that must be met for each reaction type. Write a balanced equation. Write a balanced equation. –Include phase notations. Write the ionic equation. Write the ionic equation. –Check for appropriate charges. Write the net ionic equation. (This is your answer, but the other steps may provide you with information you need to answer the questions!) Write the net ionic equation. (This is your answer, but the other steps may provide you with information you need to answer the questions!) –Eliminate spectator ions.