Photosynthesis
6CO2 + 6H2O → C6H12O6 + 6O2
Overview
The most important photochemical reaction on Earth. Plants, algae, and cyanobacteria use chlorophyll to capture sunlight and convert carbon dioxide and water into glucose and oxygen. The light reactions split water at photosystem II, while the Calvin cycle fixes CO₂. This reaction produces virtually all atmospheric oxygen and is the foundation of most food chains.
Participants
| Role | Substance | Coefficient | State |
|---|---|---|---|
| Reactant | Carbon Dioxide CO₂ | 6 | (g) |
| Reactant | Water H₂O | 6 | (l) |
| Product | Glucose C₆H₁₂O₆ | 1 | (s) |
Everyday Example
Every bite of food you eat and every breath of oxygen you inhale ultimately traces back to photosynthesis.
Industrial Importance
Photosynthesis fixes about 120 billion tonnes of carbon annually. Artificial photosynthesis research aims to produce clean fuels from sunlight.
Properties
- Type
- Photochemical
- Reversible
- No
- Energy
- Endothermic
- ΔH
- 2803.0 kJ/mol
- Catalyst
- Chlorophyll
Related Reactions
Chlorophyll Fluorescence
Cis-Trans Isomerization of Retinal
Dye-Sensitized Solar Cell (Grätzel Cell)
Firefly Bioluminescence (Luciferin Oxidation)
Luminol Chemiluminescence
Ozone Decomposition by UV
Ozone Formation by UV Light
Photocatalytic NOx Removal
Photocatalytic Water Splitting (TiO₂)
Photochemical Cycloaddition ([2+2])
Frequently Asked Questions
What is the equation for Photosynthesis?
The balanced equation is: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.
What type of reaction is Photosynthesis?
Photosynthesis is a photochemical reaction.
Is Photosynthesis exothermic or endothermic?
Photosynthesis is endothermic (absorbs energy). The enthalpy change (ΔH) is 2803.0 kJ/mol.
What conditions are needed for Photosynthesis?
This reaction requires a catalyst (Chlorophyll).