Home › ICSE Class 8 › Chemistry › Chemical Reactions and Equations › During photosynthesis, plants use sunlight to co…
During photosynthesis, plants use sunlight to convert CO₂ and water into glucose. This shows that light can:
A{'text': 'Only heat the reactants without combining them'}
B{'text': 'Always slow down chemical reactions'}
C{'text': 'Replace water as a reactant in any reaction'}
D{'text': 'Provide the energy a chemical reaction needs'}
Answer & Solution
Correct answer: D. {'text': 'Provide the energy a chemical reaction needs'}
1. Photosynthesis: 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂.
2. The reaction does not proceed in darkness because light energy is needed to break and rearrange bonds.
3. So light is supplying the **energy a chemical reaction needs** — a photochemical reaction.
4. Light can drive reactions, not slow them as a rule; it cannot replace a chemical reactant.
_Source: Selina Concise ICSE Class 8 Chemistry Ch 6 "Chemical Reactions", Factors affecting reaction rates_
Related questions
Clear limewater turns milky white when a gas is bubbled through it. Which gas was in the bMilk left standing for a few days tastes sour. Which process has produced that taste?During a chemical reaction, what happens to the atoms of the reactants?What do we call the substances that are present before a reaction takes place?What happens to the starting substances during a chemical reaction?A reducing agent in a redox reaction is the substance thatRespiration, in which glucose combines with oxygen to release energy, is best described asThe decomposition of water into hydrogen and oxygen on passing electric current is called