Types of Reactions

Types of Reactions

  • Synthesis reactions

  • Decomposition reactions

  • Single displacement reactions

  • Double displacement reactions

  • Combustion reactions

  • Important: Understand how to identify each type.

1. Synthesis Reactions

  • General Equation: A + B → AB

  • Example: C + O2 → CO

  • Details: Two substances combine to form one substance.

Example of Synthesis Reaction

  • Chemical Reaction: 2K(s) + Cl2(g) → 2KCl(s)

    • Reactants: Potassium and Chlorine

    • Product: Potassium chloride

2. Decomposition Reactions

  • General Equation: AB → A + B

  • Example: NaCl → Na + Cl

  • Details: One substance breaks down into two or more products.

Example of Decomposition Reaction

  • Chemical Reaction: 2HgO(s) → 2Hg(l) + O2(g)

    • Reactants: Mercury(II) oxide

    • Products: Mercury and Oxygen

3. Single Displacement Reactions

  • General Equation: AB + C → AC + B

  • Example: Zn + CuCl2 → ZnCl2 + Cu

  • Details: One element replaces another in a compound.

  • Oxidation/Reduction:

    • Zn: oxidized from 0 to +2

    • Cu: reduced from +2 to 0

Example of Single Replacement Reaction

  • Chemical Reaction: 2Li(s) + 2H2O(l) → 2LiOH(aq) + H2(g)

    • Reactants: Lithium and Water

    • Products: Lithium hydroxide and Hydrogen

4. Double Displacement Reactions

  • General Equation: AB + CD → AD + CB

  • Example: MgO + CaS → MgS + CaO

  • Details: The ions of two compounds exchange places in an aqueous solution.

Example of Double Replacement Reaction

  • Chemical Reaction: AgNO3(aq) + NaCl(s) → AgCl(s) + NaNO3(aq)

5. Combustion Reactions

  • Definition: A hydrocarbon reacts with oxygen gas; also known as burning.

  • Requirements for Combustion:

    1. Fuel (hydrocarbon)

    2. Oxygen

    3. Ignition source (spark)

  • General Reaction: CxHy + O2 → CO2 + H2O

  • Products: Always produces carbon dioxide and water, although incomplete combustion can produce carbon monoxide.

Example of Combustion Reaction

  • Chemical Reaction: C5H12 + O2 → CO2 + H2O

Mixed Practice

  • Predict the product and state the type for:

    • BaCl2 + H2SO4

    • C6H12 + O2

    • Zn + CuSO4

    • Cs + Br2

    • FeCO3