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