Comprehensive Stoichiometry and Reaction Types Guide

Stoichiometry
Dissolvable in Water (aq)
1. Dissolvable: Nitrates (NO3), Acetates (CH3COO), Ammonium (NH4), and Group 1 salts.
2. Dissolvable: Chlorides (Cl), Bromides (Br), and Iodides (I) except when combined with
Silver (Ag), Lead (Pb), and Mercury (I) - Hg.
3. Dissolvable: Fluorides (Fl) except when paired with Group 2 elements, Lead (II), and
Iron (III).
4. All sulfates (SO4^2-) except those of Calcium, Strontium, Barium, Mercury, Lead (II),
and Silver.
Insoluble in Water (s)
1. All carbonates and phosphates except those of Group I and Ammonium.
2. All hydroxides (OH) except those of Group I, Strontium, Barium, and Ammonium.
3. All sulfides except those of Group I and II and Ammonium.
4. All oxides (O2) except those of Group I.



Types of Reactions
 Synthesis/Combination
 Decomposition
 Single Replacement
 Double Replacement (also known as double-displacement reactions)
 Combustion
 Neutralization
 Oxidation-Reduction
Synthesis/Combination Reactions Rules:
 Formation of a binary compound: ( A + B  AB )
 Metal oxide-water reactions: ([Metal]O + H_2O  [base])
 Nonmetal oxide-water reactions: ([Nonmetal]O + H_2O  [acid])
 Two reactants combine to form one product.
Decomposition Reactions

,  Binary compounds: ( AB A + B )
 Metallic carbonates: ([Metal]CO_3  [Metal]O + CO_2)
 Metallic hydrogen carbonates: ([Metal]HCO_3  [Metal]O + H_2O)
 Metallic hydroxides: ([Metal]OH  [Metal]O + H_2O)
 Metallic chlorates: ( MClO_3  [Metal]Cl + O_2 )
 Oxyacids decompose to nonmetal oxides and water: ([Acid]  [Nonmetal]O + H_2O)
 A product breaks down into two reactants.
Single Replacement Reactions
 Metal replaces metal: ( A + BC AC + B )
 Active metal replaces hydrogen from water: ([Metal] + H_2O  [Metal]OH + H_2)
 Active metal replaces hydrogen from acid: ([Metal] + H[acid]  [Metal][Acid] + H_2)
 Halide-Halide replacement: ([Halide A] + B[Halide B]  [Halide B] + B[Halide A])
 One element and one compound react.
 “Like replaces like” - cations/anions displace each other.
Metals can only displace another metal if they are more reactive than the metal they aim to
replace. An activity series graph illustrates the reactivities of various metals. Generally, reactivity
increases as you move down the periodic table and decreases as you move from left to right. If a
metal is less reactive than the one it tries to replace, no reaction will occur.
Double Replacement Reactions
 ( AB + CD AD + CB ) (Outer-Outer, Inner-Inner)
 Formation of a precipitate from a solution.
 Acid-Base neutralization reaction.
 Two compounds form two new compounds (states of matter must be included).
Combustion Reactions
 Hydrocarbon + oxygen  carbon dioxide + water
“Combustion” means burning; burning a hydrocarbon (any CH combo) with O_2 produces
carbon dioxide and water. The result is always ( CO_2 + H_2O ).
Acid-Base Neutralization Reactions
 Similar to double replacement reactions:
 ([Acid] (H) + [Base] (OH)  salt (ionic compounds) + H_2O)