Question

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.

Answer 1

\[\ce{6CO2 + 6H2O ->[ChlorophyII][Sunlight] C6H12O6 + 6O2}\]

1 mole (180g) of glucose needs 6 moles (6 × 18 g) of H₂O

1 g of glucose will need `108/180` g of H₂O

18 g of glucose will need `108/180 xx 18 = 10.8 g`

volume of water used = `"Mass"/"Density"`

= `10.8/1`

= 10.8 cm³