[Bioionic]

I was trying to work out a sucrose to CO2 gas production problem.
I worked it as follows.
From the chemical formula for sugar to CO2 we get:

C12H22O11 ----> 4 CO2 (I left out the other products) So 1 mole sucrose yields 4 mole CO2
1mole C12H22O11 is about 342g/mole which is about 3/4 pound of sugar.
1 mole of sugar will make about 4(44g CO2/1 mole CO2) = 176 g CO2.

Since density of CO2 is 1.56g/ml the amount of CO2 produced from 1 mole of sugar is...

I use density formula here.
1 mole C12H22O11 ----> 176g CO2 x (1mL/1.56g CO2) = 112.8 mL CO2

I thought this was right but someone pointed out that 1 mole of gas is 22.4L so where did I go wrong?

So would 4 mole CO2 at  176gram = 112.8mL or is it4x22.4L? Am I just confusing myself?

Thanks

[Borek]

Density of gaseous CO₂ is not 1.56 g/mL.

Please show full balanced reaction equation. What happened to the other eight carbon atoms?

[Bioionic]

Your right, I screwed up the equation. I don't know what I was thinking. The formula for cell respiration is
6O2 + C6H12O6 ---> 6CO2 + 6H2O
I was thinking it was 2CO2 so I figured sucrose would be double the CO2, so I came up with 4CO2.

I got the 1.56g/ml number from the internet.
http://www.science-house.org/learn/CountertopChem/exp9.html


BTW, this is not a homework question. I was in a beer brewing discussion and it was asked how much CO2 was produced.

[Borek]

I got the 1.56g/ml number from the internet.

Don't believe everytjhing you find on internet. These are densities in g/L, not mL.

Now, during brewing there is also ethanol produced, so not necesarilly all carbon goes into carbon dioxide.

Note that volume of one mole of CO₂ is 22.4 L at STP (around 0 deg C and 1 atm). Usually you will work at higher temp, so the volume will be higher.

[Bioionic]

Your right, I screwed up the equation. I don't know what I was thinking. The formula for cell respiration is
6O2 + C6H12O6 ---> 6CO2 + 6H2O
I was thinking it was 2CO2 so I figured sucrose would be double the CO2, so I came up with 4CO2.

I got the 1.56g/ml number from the internet.
http://www.science-house.org/learn/CountertopChem/exp9.html


BTW, this is not a homework question. I was in a beer brewing discussion and it was asked how much CO2 was produced.

I need to make a correction here. I was right the first time.  The above equation is for cell respiration, but were talking fermentation here so there is no O2 in the equation.

For glucose frementation, the formula is :
C6H12O6 + energy ------> 2C2H5OH + 2CO2 + 2H2O

Since Sucrose is a disaccharide the enzyme invertase first breaks the sucrose to glucose.  So the product of Sucrose (glucose x 2)  is 2(2CO2) with the excess carbon producing Ethanol. So I think I was right that 1 mole sucrose ---> 4 mole CO2.

Just thought I should make that correction.