What are the 13 types of chemical reactions?
2 Answers
Chemical reactions can be classified into several types based on how the reactants transform into products. Here are 13 common types of chemical reactions:
1. **Synthesis (Combination) Reaction**:
- **Definition**: Two or more simple substances combine to form a more complex product.
- **General Form**: \( A + B \rightarrow AB \)
- **Example**: 2H₂ + O₂ → 2H₂O (Hydrogen and oxygen combine to form water).
2. **Decomposition Reaction**:
- **Definition**: A complex molecule breaks down into simpler substances.
- **General Form**: \( AB \rightarrow A + B \)
- **Example**: 2H₂O → 2H₂ + O₂ (Water decomposes into hydrogen and oxygen gases).
3. **Single Replacement (Displacement) Reaction**:
- **Definition**: One element replaces another in a compound.
- **General Form**: \( A + BC \rightarrow AC + B \)
- **Example**: Zn + 2HCl → ZnCl₂ + H₂ (Zinc replaces hydrogen in hydrochloric acid).
4. **Double Replacement (Metathesis) Reaction**:
- **Definition**: The ions in two compounds exchange places to form two new compounds.
- **General Form**: \( AB + CD \rightarrow AD + CB \)
- **Example**: AgNO₃ + NaCl → AgCl + NaNO₃ (Silver nitrate reacts with sodium chloride to form silver chloride and sodium nitrate).
5. **Combustion Reaction**:
- **Definition**: A substance reacts with oxygen, releasing energy in the form of light or heat.
- **General Form**: \( C_xH_y + O₂ \rightarrow CO₂ + H₂O \)
- **Example**: CH₄ + 2O₂ → CO₂ + 2H₂O (Methane burns in oxygen to produce carbon dioxide and water).
6. **Neutralization Reaction**:
- **Definition**: An acid reacts with a base to produce water and a salt.
- **General Form**: \( HA + BOH \rightarrow H₂O + AB \)
- **Example**: HCl + NaOH → NaCl + H₂O (Hydrochloric acid reacts with sodium hydroxide to form sodium chloride and water).
7. **Oxidation-Reduction (Redox) Reaction**:
- **Definition**: Involves the transfer of electrons between substances. One substance is oxidized (loses electrons) and another is reduced (gains electrons).
- **General Form**: Varies; involves changes in oxidation states.
- **Example**: 2Na + Cl₂ → 2NaCl (Sodium is oxidized, chlorine is reduced).
8. **Precipitation Reaction**:
- **Definition**: Two soluble salts react in solution to form an insoluble product (precipitate).
- **General Form**: \( AB_{(aq)} + CD_{(aq)} \rightarrow AD_{(s)} + CB_{(aq)} \)
- **Example**: Pb(NO₃)₂ + 2KI → PbI₂ (s) + 2KNO₃ (Lead nitrate reacts with potassium iodide to form lead iodide precipitate).
9. **Complexation Reaction**:
- **Definition**: A reaction where a complex ion is formed from a metal ion and ligands.
- **General Form**: Varies; typically involves metal ions and ligands forming a complex.
- **Example**: [Fe(CN)₆]⁴⁻ + 6K⁺ → K₆[Fe(CN)₆] (Formation of potassium hexacyanoferrate).
10. **Hydrolysis Reaction**:
- **Definition**: A compound reacts with water, often resulting in the breakdown of the compound.
- **General Form**: \( AB + H₂O \rightarrow AOH + BH \)
- **Example**: Na₂CO₃ + H₂O → 2NaOH + CO₂ (Sodium carbonate reacts with water).
11. **Photochemical Reaction**:
- **Definition**: A reaction triggered by light energy.
- **General Form**: Depends on the reaction; involves light as a reactant.
- **Example**: 2AgBr → 2Ag + Br₂ (Silver bromide decomposes into silver and bromine upon exposure to light).
12. **Electrolytic Reaction**:
- **Definition**: A reaction driven by electrical current, often used in electrolysis.
- **General Form**: Varies; involves decomposition or synthesis driven by electricity.
- **Example**: 2H₂O → 2H₂ + O₂ (Water is electrolyzed to produce hydrogen and oxygen gases).
13. **Combustion Reaction**:
- **Definition**: Similar to combustion, but often refers specifically to reactions involving organic compounds in oxygen.
- **General Form**: C_xH_y + O₂ → CO₂ + H₂O
- **Example**: C₅H₁₂ + 8O₂ → 5CO₂ + 6H₂O (Pentane burns in oxygen to produce carbon dioxide and water).
These reactions cover a wide range of chemical processes, illustrating how substances interact and transform in different scenarios.
1. **Synthesis (Combination) Reaction**:
- **Definition**: Two or more simple substances combine to form a more complex product.
- **General Form**: \( A + B \rightarrow AB \)
- **Example**: 2H₂ + O₂ → 2H₂O (Hydrogen and oxygen combine to form water).
2. **Decomposition Reaction**:
- **Definition**: A complex molecule breaks down into simpler substances.
- **General Form**: \( AB \rightarrow A + B \)
- **Example**: 2H₂O → 2H₂ + O₂ (Water decomposes into hydrogen and oxygen gases).
3. **Single Replacement (Displacement) Reaction**:
- **Definition**: One element replaces another in a compound.
- **General Form**: \( A + BC \rightarrow AC + B \)
- **Example**: Zn + 2HCl → ZnCl₂ + H₂ (Zinc replaces hydrogen in hydrochloric acid).
4. **Double Replacement (Metathesis) Reaction**:
- **Definition**: The ions in two compounds exchange places to form two new compounds.
- **General Form**: \( AB + CD \rightarrow AD + CB \)
- **Example**: AgNO₃ + NaCl → AgCl + NaNO₃ (Silver nitrate reacts with sodium chloride to form silver chloride and sodium nitrate).
5. **Combustion Reaction**:
- **Definition**: A substance reacts with oxygen, releasing energy in the form of light or heat.
- **General Form**: \( C_xH_y + O₂ \rightarrow CO₂ + H₂O \)
- **Example**: CH₄ + 2O₂ → CO₂ + 2H₂O (Methane burns in oxygen to produce carbon dioxide and water).
6. **Neutralization Reaction**:
- **Definition**: An acid reacts with a base to produce water and a salt.
- **General Form**: \( HA + BOH \rightarrow H₂O + AB \)
- **Example**: HCl + NaOH → NaCl + H₂O (Hydrochloric acid reacts with sodium hydroxide to form sodium chloride and water).
7. **Oxidation-Reduction (Redox) Reaction**:
- **Definition**: Involves the transfer of electrons between substances. One substance is oxidized (loses electrons) and another is reduced (gains electrons).
- **General Form**: Varies; involves changes in oxidation states.
- **Example**: 2Na + Cl₂ → 2NaCl (Sodium is oxidized, chlorine is reduced).
8. **Precipitation Reaction**:
- **Definition**: Two soluble salts react in solution to form an insoluble product (precipitate).
- **General Form**: \( AB_{(aq)} + CD_{(aq)} \rightarrow AD_{(s)} + CB_{(aq)} \)
- **Example**: Pb(NO₃)₂ + 2KI → PbI₂ (s) + 2KNO₃ (Lead nitrate reacts with potassium iodide to form lead iodide precipitate).
9. **Complexation Reaction**:
- **Definition**: A reaction where a complex ion is formed from a metal ion and ligands.
- **General Form**: Varies; typically involves metal ions and ligands forming a complex.
- **Example**: [Fe(CN)₆]⁴⁻ + 6K⁺ → K₆[Fe(CN)₆] (Formation of potassium hexacyanoferrate).
10. **Hydrolysis Reaction**:
- **Definition**: A compound reacts with water, often resulting in the breakdown of the compound.
- **General Form**: \( AB + H₂O \rightarrow AOH + BH \)
- **Example**: Na₂CO₃ + H₂O → 2NaOH + CO₂ (Sodium carbonate reacts with water).
11. **Photochemical Reaction**:
- **Definition**: A reaction triggered by light energy.
- **General Form**: Depends on the reaction; involves light as a reactant.
- **Example**: 2AgBr → 2Ag + Br₂ (Silver bromide decomposes into silver and bromine upon exposure to light).
12. **Electrolytic Reaction**:
- **Definition**: A reaction driven by electrical current, often used in electrolysis.
- **General Form**: Varies; involves decomposition or synthesis driven by electricity.
- **Example**: 2H₂O → 2H₂ + O₂ (Water is electrolyzed to produce hydrogen and oxygen gases).
13. **Combustion Reaction**:
- **Definition**: Similar to combustion, but often refers specifically to reactions involving organic compounds in oxygen.
- **General Form**: C_xH_y + O₂ → CO₂ + H₂O
- **Example**: C₅H₁₂ + 8O₂ → 5CO₂ + 6H₂O (Pentane burns in oxygen to produce carbon dioxide and water).
These reactions cover a wide range of chemical processes, illustrating how substances interact and transform in different scenarios.