# 4.S: Reactions in Aqueous Solution (Summary)


aqueous solutions – solutions in which water is the dissolving medium

## 4.1: General Properties of Aqueous Solutions

• electrolyte – substance whose aqueous solution contains ions
• nonelectrolyte – substance that does not form ions in solution

### 4.2.1 Ionic Compounds in Water

• dissociate – when ions separate from a solid being dissolved

### 4.2.2 Molecular Compounds in Water

• the molecular structure is maintained

### 4.2.3 Strong and Weak Electrolytes

• strong electrolytes – ionic compounds that exists entirely of ions in solution
• weak electryolytes – molecular compounds that produce a small amound of ions
• chemical equilibrium – equilibrium of forming ions and recrystalizing ions

## 4.2: Precipitation Reactions

$AX + BY \rightarrow AY + BX \nonumber$

• for methathesis to occur:
1. the formation of an insoluble product
2. the formation of either a weak electrolyte or a nonelectrolyte
3. the formation of a gas that escapes from solution

### 4.5.1 Precipitation Reactions

• precipitate – insoluble solid formed by a reaction in solution
• solubility – amount of substance that can be dissolved in a given quantity

### 4.5.2 Solubility Guidelines for Ionic Compounds

• all common ionic compounds of the alkali metal ions and of the ammonium ion are soluble in water

### 4.5.3 Reactions in Which a Weak Electrolyte or Nonelectrolyte Forms

• hydrogen and hydroxide react to form water
• insoluble metal oxides react with acids

## 4.3: Acid-Base Reactions

### 4.3.1 Acids

• substances that ionize to form hydrogen ions
• proton donors

### 4.3.2 Bases

• substances that ionize to form hydroxide ions

### 4.3.3 Strong and Weak Acids and Bases

• strong acid, strong base – strong electrolyte
• weak acid, weak base – weak electrolyte

### 4.3.4 Neutralization Reactions and Salts

• neutralization reaction – when an acid and base are mixed
• produces water and a salt

### 4.4 Ionic Equations

• molecular formula – and equation written to show the complete chemical formulas of reactants and products
• spectator ions – ions that do not play a role in a reaction
• net ionic equation – equation where the spectator ions are removed
• only soluble strong electrolytes are written in ionic form

## 4.4: Oxidation-Reduction Reactions

### 4.6.1 Reactions in Which a Gas Forms

• carbonates and bicarbonates

### 4.6.2 Oxidation and Reduction

• oxidation – loss of electrons
• reduction – gain of electrons

### 4.6.3 Oxidation of Metals by Acids and Salts

• whenever one substance is oxidized, some other substance must be reduced
• metals react with acids to form salts and hydrogen gas

### 4.6.4 The Activity Series

• activity series – list of metals arranged in order of decreasing ease of oxidation
• active metals – alkali metals and alkaline earth metals
• any metal on the list can be oxidized by ions of elements below it

## 4.5: Concentration of Solutions

• solution – homogeneous mixture of two or more substances
• solvent – component that is present in greatest quantity
• solutes – substances dissolved in the solvent

### 4.1.1 Molarity

• concentration – the amount of solute dissolved in a given quantity of solvent or solution
• molarity – number of moles of solute in a liter of solution

### 4.1.2 Dilution

• dilution - obtaining a lower concentration of a solution by adding water
• moles solute before dilution = moles solute after dilution

## 4.6: Solution Stoichiometry and Chemical Analysis

### 4.7.1 Titrations

• statndard solution – solution of known concentration
• titration – a known solution that undergoes a specific chemical reaction of known stoichiometry with the solution of unknown concentration
• equivalence point – stoichiometrically equivalent quantities of reactants are brought together
• indicator – used to show the endpoint of the titration

4.S: Reactions in Aqueous Solution (Summary) is shared under a CC BY-NC-SA 3.0 license and was authored, remixed, and/or curated by LibreTexts.