CH 202 Problem 3.58

3.58 The fermentation of glucose (C6H12O6) produces ethyl alcohol (C2H5OH) and CO2:

C6H12O6(aq) ---> 2C2H5OH(aq) + 2CO2(g)

(a) How many mol of CO2 are produced when 0.400 mol of C6H12O6 are reacted in this fashion?

Treat this as a dimensional analysis problem: we are converting 0.400 mol glucose to mol carbon dioxide, and the conversion factor is the coefficients in the balanced chemical equation. We see that glucose is related to CO2 by a 1:2 ratio, so converting mol glucose, we have

(dummy units)

(b) How many grams of C6H12O6 are needed to form 7.50 g of C2H5OH ?

again, treat this as a dimensional analysis problem...

we convert g C2H5OH --> mol C2H5OH --> mol C6H12O6 --> g C6H12O6

note that the only new thing here is the mol -mol conversion - just use the stoichiometric coeffiecients in the balanced equation.

molar mass of C6H12O6

molar mass of C2H5OH

go for it...

(c) How many grams of CO2 form when 7.50 g of C2H5OH are produced?

The beauty thing about the balanced equation is that we can convert moles of any species to moles of any other species provided we have the stoichiometric coefficients. Here, we will go

g C2H5OH -> mol C2H5OH --> mol CO2 --> g CO2

molar mass of CO2:

let's do this thing:

DAC 7/2/08