Question

A particular yeast ferments glucose (c6h12o6; molar mass = 180.2 g/mol) and generates ethanol (c2h5oh; molar mass = 46.07 g/mol) with an 87% yield. what mass of glucose is required to produce 475 g of ethanol by this process?

Answer 1

First, you have to write down the equation from glucose, C₆H₁₂O₆, to ethanol, C₂H₅OH.

C₆H₁₂O₆ --> 2 C₂H₅OH + CO₂

So, the ratio for glucose to ethanol is 1:2. The solution is as follows:

Mass of glucose required = (475 g)(0.87)(1mol/46.07 g ethanol)(1mol gluose/2 mol ethanol)(180.2 g/mol glucose)
Mass of glucose required = 808.2 g