Chemical Reactions Overview

Chemical Reactions

• Types of Reactions:

  • Double Displacement: Cations and anions switch partners.
  • Combustion: Hydrocarbon reacts with oxygen to form CO2 and H2O.
  • Synthesis: Two or more reactants combine to form one product.
  • Decomposition: A single compound breaks down into two or more products.
  • Single Replacement: One element replaces another in a compound.
  • Double Replacement: Two compounds trade components to form new compounds.
  • Acid-Base: Reaction between acid and base forms water.

• Balancing Equations: Adjusting coefficients to ensure the same number of atoms of each element on both sides of the equation.

• Activity Series: A list that predicts metal reactivity in single replacement reactions.

• Ionic Compounds: Composed of cations and anions, requiring balanced positive and negative charges.

• Neutral Ionic Compounds: Compounds with a balanced charge between positive and negative ions.

Solution Chemistry

• Solutions: Mixtures of solute and solvent, resulting in a uniform distribution of particles at a molecular level.

• Solute: The substance dissolved.

• Solvent: The substance that dissolves the solute.

• Types of Solutions:

  • Unsaturated: Can dissolve more solute.
  • Saturated: Cannot dissolve more solute at a given temperature.
  • Supersaturated: Contains more solute than a saturated solution can hold at a given temperature.

• Factors Affecting Dissolving Rate:

  • Agitation: Stirring increases dissolving rate
  • Temperature: Increasing temperature usually increases dissolving rate
  • Particle Size: Smaller particles dissolve faster.

• Solubility: Ability of a substance to dissolve in a solvent.

• Solubility Curves: Graphs showing solubility of a substance at different temperatures.

• Saturated Solutions: Contains the maximum amount of solute the solvent can hold at a specific temperature.

• Calculations: Determining the amount of solute needed to prepare a saturated solution at a given temperature from a solubility curve, or finding solubility of a compound at a specific temperature using a solubility graph.

• Molarity: The concentration of a solution expressed in moles of solute per liter of solution.

Chemical Properties

• Reactants: Substances present before a chemical reaction.

• Products: Substances formed as a result of a chemical reaction.

• Energy Changes:

  • Exothermic: Reactions releasing energy, often as heat.
  • Endothermic: Reactions absorbing energy from the surroundings.

• Chemical Equations: Symbolic representations of chemical reactions.

• Precipitates: Insoluble solids produced in some chemical reactions.

• Spontaneous Reactions: Reactions occurring without external influence.

• Non-Spontaneous Reactions: Reactions requiring energy input.

• Conservation of Mass: Mass is neither created nor destroyed during a chemical reaction.

• Molecular Formula: Provides types and numbers of atoms in a compound.

• Coefficients: Numbers in chemical equations indicating the mole ratio of reactants and products.

• Symbols of State: Used in chemical equations to indicate the physical state (solid, liquid, gas, aqueous).

• Condition symbols: Specific requirements for initiating a reaction.

• Colligative Properties: Properties of a solution that depend ONLY on the number of dissolved particles, not on the identity of the particle.

• Colligative Property Examples: Vapor pressure lowering, boiling point elevation, and freezing point depression.

• Particle Formation: Number of particles produced when an ionic compound dissolves.