Question

Photosynthesis reactions in green plants use carbon dioxide and water to produce glucose (C6H12O6) and oxygen. A plant has 88.0 g of carbon dioxide and 64.0 g of water available for photosynthesis

Answer 1

The given question is incomplete. The complete question is:

Photosynthesis reactions in green plants use carbon dioxide and water to produce glucose (C6H12O6) and oxygen. A plant has 88.0 g of carbon dioxide and 64.0 g of water available for photosynthesis. Determine the mass of glucose (C6H1206) produced

Answer: 60.0 g of glucose

Explanation:

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}$

a) moles of $CO_2$

$\text{Number of moles}=\frac{88.0g}{44g/mol}=2.0moles$

b) moles of $H_2O$

$\text{Number of moles}=\frac{64.0g}{18g/mol}=3.5moles$

$6CO_2+6H_2O\rightarrow C_{6}H_{12}O_6+6O_2$

According to stoichiometry :

6 moles of $CO_2$ require = 6 moles of $H_2O$

Thus 2.0 moles of $CO_2$ require=$\frac{6}{6}\times 2.0=2.0moles$  of $H_2O$

Thus $CO_2$ is the limiting reagent as it limits the formation of product.

As 6 moles of $CO_2$ give =  1 moles of glucose

Thus 2.0 moles of $CO_2$ give =$\frac{1}{6}\times 2.0=0.33moles$  of glucose

Mass of glucose = $moles\times {\text {Molar mass}}=0.33moles\times 180g/mol=60g$

Thus 60.0 g of glucose will be produced from 88.0 g of carbon dioxide and 64.0 g of water