In photosynthesis, 6 molecules of carbon dioxide combine with an equal number of water molecules through a complex series of reactions to give a molecule of glucose having a molecular formula C6 H12 O6 . How many grams of water would be required to produce 18 g of glucose? Compute the volume of water so consumed assuming the density of water to be 1 g cm-3.
ScienceClass 9CBSEAnswered 27 Mar 2026
Answer
Soln:
6CO2 + 6 H2 O Chlorophyll /Sunlight → C6 H12 O6 + 6O2
1 mole of glucose needs 6 moles of water 180 g of glucose needs (6×18) g of water 1 g of glucose will need 108/ 180 g of water.
18 g of glucose would need (108 /180) × 18 g of water = 10.8 g Volume of water used = Mass
Density
= 10.8 g/ 1g cm-3
=10.8 cm3
Suggested Q&A
Science · Class 9- ScienceClass 91. Why does the temperature of a substance remain constant during its melting point or boiling point?
- ScienceClass 9Comment on the following statements: (a) Evaporation produces cooling. (b) Rate of evaporation of an aqueous solution decreases with increase in humidity. Sponge though compressible is a solid.
- ScienceClass 9You want to wear your favourite shirt to a party, but the problem is that it is still wet after a wash. What steps would you take to dry it faster?
- ScienceClass 9It is a hot summer day, Priyanshi and Ali are wearing cotton and nylon clothes respectively. Who do you think would be more comfortable and why?
- ScienceClass 9Alka was making tea in a kettle. Suddenly she felt intense heat from the puff of steam gushing out of the spout of the kettle. She wondered whether the temperature of the steam was higher than that of the water boiling in the kettle. Comment
- ScienceClass 9Water as ice has a cooling effect, whereas water as steam may cause severe burns. Explain these observations.