Ethanol can be made by fermentation of a solution of glucose, a carbohydrate - Edexcel - GCSE Chemistry - Question 5 - 2023 - Paper 2

To calculate the concentration of the glucose solution in g dm⁻³, we can use the formula:

$\text{Concentration (g dm}^{-3}\text{)} = \frac{\text{mass of solute (g)}}{\text{volume of solution (dm}^3\text{)}}$

The mass of glucose is 45 g and the volume of the solution is 150 cm³, which is equivalent to 0.15 dm³. Therefore, the concentration is:

$\text{Concentration} = \frac{45\, \text{g}}{0.15\, \text{dm}^3} = 300\, \text{g dm}^{-3}$

To initiate the fermentation reaction, yeast should be added to the glucose solution. Yeast contains enzymes that convert glucose to ethanol and carbon dioxide through fermentation.