Question

When grape juice is fermented, glucose (C6H12O6) is converted to ethanol (C2H6O) and carbon dioxide. Please show work.

a.) Write a balanced chemical equation for the reaction. (There are not any other reactants or products.)

   C6H12O6 -> C2H6O + CO2     is this correct?

b.) How many grams of glucose are needed to form 150 g of ethanol?

c.) If a grape juice sample dontains 4.50 kg of glucose, how manu grams of ethanol can be produced?

d.) How many milligrams of carbon dioxide can be produced from 0.778 g of glucose?

Answer 1

A) Balance equation

Glucose -> Ethanol + CO2

C6H12O6 -> 2CH3CH2OH + 2 CO2

B)

1 mol of glucose -> 2 mol of ethanol

we want only 150 g of ethanol

MW ethanol = 46 g/gmol

moles = Mass / MW = 150g/46g/gmol = 3.26 gmol of Ethanol

we need half moles of that so... 3.26/2

1.63 moles of glucose will give that amount

C)

m glucose = 4.5 kg

MW glucose = 180 g/gmol

n of glucose = mass/MW = 4500 g/ 180 g/gmol = 25 gmol of Glucose

1 gmol of glucose produces 2 gmol of ethanol so...

25*2 = 50 gmol of ethanol will bne produced

but we need mass

m = moles * MW = 50 gmol *46 g/gmol = 2300 g or 2.3 kg of ethanol

d)

mg of CO2 if we ferment 0.778 g of glucose

change to moles

moles of Glucose = mass glucose / MW = 0.778 / 180 = 0.0043 gmol of Glucose

1 mol of Glucose :2 moles of CO2

then 2*0.0043 = 0.00864 gmol of CO2 will be produced

but we need mass so:

mass = moles * MW

mass = 0.00865 gmol * 44 g/gmo =0.38 grams or 380 mg of CO2