Types of Reactions

Synthesis

• A synthesis reaction is when two or more reactants combine to form a compound.

Formula:  A + B --> C

Examples:

• 1Ca + 1Cl₂ --> 1CaCl₂
• Na + Cl₂ --> 
• 2Na + 1Cl₂ --> 2NaCl
• 1H₂ + 1F₂ -->  2HF
• Al + Cl₂ -->  
• 2Al + 3Cl₂ --> 2AlCl₂
• 6Li + 1N₂ --> 2Li₃N

Decomposition

• A decomposition reaction is when a compound degrades into two or more products.

Formula:  A --> B + C

Examples:

• 2H₂O --> 2H₂ + 1O₂
• KNO₃ -->
• 2KNO₃ --> 2KNO₂ + 1O₂
• NF₃ --> 1N₂ + 3F₂
• MgO -->
• 2MgO --> 2Mg + 1O₂
• 2NaCl --> 2Na + 1Cl₂

Single Replacement

• A single replacement(or displacement) reaction is when one element replaces another element in a compound.

Formula for Metal:  A + BC --> AC + B

Formula for Non-Metal:  A + BC --> BA + C

Examples:

• 6K + 1Al₂O₃ --> 3K₂O + 1Al
• Al + FeCl₂ -->
• 2Al + 3FeCl₂ --> 2AlCl₃ + 3Fe
• 2AgCl + 1Mg --> 2Ag + 1MgCl₂
• Zn + H₂SO₄ -->
• 1Zn + 1H₂SO₄ --> 1ZnSO₄ + 1H₂
• 1Cl₂ + 2KBr --> 2KCl + 1Br₂

Activity Series

• Elements higher on the chart can replace elements below it, but elements lower on the chart cannot replace elements higher on the chart.

For example:

Fe + Al2O3 --> N.R., because iron is lower on the activity series chart than aluminum, it cannot replace it. When this occurs we label it N.R. for no reaction.