How do you convert GtCO2 to GtC?

Katchit said:

How do you convert GtCO2 to GtC?

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If I did my math right, have 1 gigapopulus breathe 2lbCO[sub]2[/sub] quotidian for 3 years.

A gigaton is 10^9 tons. So, 107 and move the decimal over 9 places.

Plants are quite adept at converting CO2 into C & O2

Katchit said:

Hi everyone.

This is a bit of a different post to that which i would usually make however - i am not the best at maths or conversions - and this forum is always very helpful therefore i thought i would see which maths / science experts on here could possibly help me please

If i wanted to convert 107 GtCO2 so i obtained the GtC figure ; how would i do so please?

How do i then go from GtC to CO2?

I am also interested in obtaining the MtCO2 how would i go about it?

The query is - Obtain the figure for CO2 if the MtCO2 is 627.12.

I just cant seem to work any of them out and i am becoming really confused so any help would be great! Thank you.

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Divide or multiply by 3.67 depending which way you want to convert.

1 ton of CO2 has 1/3.67 = 0.2725 tons of C in it.

Katchit said:

Hi everyone.

This is a bit of a different post to that which i would usually make however - i am not the best at maths or conversions - and this forum is always very helpful therefore i thought i would see which maths / science experts on here could possibly help me please

If i wanted to convert 107 GtCO2 so i obtained the GtC figure ; how would i do so please?

How do i then go from GtC to CO2?

I am also interested in obtaining the MtCO2 how would i go about it?

The query is - Obtain the figure for CO2 if the MtCO2 is 627.12.

I just cant seem to work any of them out and i am becoming really confused so any help would be great! Thank you.

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Hmmmm. I'm not sure what you are trying to do as your notation is not quite clear to me,which is probably my shortcoming. I gather Gt is "gigatons" and Mt is "metric tons. Are you trying to find out what the mass or weight of carbon is in 107 Gt of carbon dioxide?

If so 2 atoms of oxygen would be 2(16) or 32 and 1 atom of carbon would be 12. Then the ratio would be 12/32 or 3/8

Therefore: 3/8 x 107 Gt = 40.125 Gt

Now, assuming my approach is correct, which it probably isn't; but on the small chance that it just might be, I must ask another question. What is the source of your carbon? This would matter as it probably contains 14C, 13C and 12C. Also there is a difference in oxygen as well due to fractionation which would yield mostly 16O but some 18O as well.

Cheers!

RickG said:

Hmmmm. I'm not sure what you are trying to do as your notation is not quite clear to me,which is probably my shortcoming. I gather Gt is "gigatons" and Mt is "metric tons. Are you trying to find out what the mass or weight of carbon is in 107 Gt of carbon dioxide?

If so 2 atoms of oxygen would be 2(16) or 32 and 1 atom of carbon would be 12. Then the ratio would be 12/32 or 3/8

Therefore: 3/8 x 107 Gt = 40.125 Gt

Now, assuming my approach is correct, which it probably isn't; but on the small chance that it just might be, I must ask another question. What is the source of your carbon? This would matter as it probably contains 14C, 13C and 12C. Also there is a difference in oxygen as well due to fractionation which would yield mostly 16O but some 18O as well.

Cheers!

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You did it wrong - it is (2*16 + 12)/12 = 3.67 (or 1/3.67 for the other way).

Its just a chemical equation.

Maybe the Gt is imperial, and the Mt metric. That'd add a nice twist. My guess though is it is giga and mega.

NGC 6712 said:

You did it wrong - it is (2*16 + 12)/12 = 3.67 (or 1/3.67 for the other way).

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Are you sure? I was just calculating the weight of carbon in 107 Gt of CO2, not both carbon and oxygen, by determining the ratio between the two. But I admit I have not done those types of calculations for some time and that was completely from memory from many many moons ago. Please advise, I just want to be sure we are talking about the same thing.

Katchit said:

If i wanted to convert 107 GtCO2 so i obtained the GtC figure ; how would i do so please?

How do i then go from GtC to CO2?

I am also interested in obtaining the MtCO2 how would i go about it?

The query is - Obtain the figure for CO2 if the MtCO2 is 627.12.

I just cant seem to work any of them out and i am becoming really confused so any help would be great! Thank you.

Click to expand...

Here's how we teach it in Chem class:

If you have 107gigatons of CO2 you want to convert to gigatons of C.

First let's get everything into grams (it'll make sense in a bit):

First conversion (when I do these conversions I rely on the idea that if I multiply a number by a "conversion factor" that is in the form of a ratio I can cancel out the units and arrive at the desired unit):

107gigatons CO2 X 1billion tons/gigaton = 107,000,000,000tons CO2
(note that the "gigaton" is in the denominator so it cancels out with the gigatons of the 107gigatons leaving me with "tons", this is how we will proceed with "conversion factors))

107,000,000,000tons CO2 x 2000lb/ton = 2.14x10^14 lbs CO2

2.14x10^14 lbs CO2 x 1kg/2.2lb = 9.73x10^13kg

9.73x10^13kg x 1000g/kg =9.73x10^16g

Why all that thrash? Because I want to use the periodic table to get the number of moles of CO2 (the mole is the currency of the realm of chemistry, we can discuss what a mole is separately if you like)

1mole CO2 = 12.011g+15.9994g +15.9994g = 44.0098g/mol
(this is the molecular mass of CO2, you get these values off the periodic table)

that means that 9.73x10^16g CO2 will be:

9.73x10^16g x 1mol/44.0098g = 2.21x10^15mol CO2

1 mol CO2 contains 1 mol C (if you want a deeper discussion of the "Mole" concept we can go over that separately)

that means that 2.21x10^15mol CO2 x 1molC/1molCO2 = 2.21x10^15molC

Now we just walk backwards through the calculations as we did getting to this point.

2.21x10^15molC x 12.011g/molC <--this is the atomic mass of C

2.65x10^16gC

2.65x10^16gC x 1kg/1000g = 2.65x10^13kgC

2.65x10^13kgC x 2.2lb/kg = 5.84x10^13lb C

5.84x10^13lb C x 1ton/2000lb = 2.92x10^10ton C

2.92x10^10ton C x 1Gt/1billion tons 29.2Gt C

Now if you want to convert to METRIC TONS at any point remember that

1 metric ton = 1000kg
1 metric ton = 2204.6lb

So you can convert from any point in the weight steps.

RickG said:

Are you sure? I was just calculating the weight of carbon in 107 Gt of CO2, not both carbon and oxygen, by determining the ratio between the two. But I admit I have not done those types of calculations for some time and that was completely from memory from many many moons ago. Please advise, I just want to be sure we are talking about the same thing.

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You effectively ignored the C in the CO2.

A mole of CO2 has a mass of 44g. Of that 44g, 12g is carbon. Therefore the fraction of the mass that is carbon is 12/44 = 3/11 = 0.2727 (or as I left it 1/3.67)

Thus 107 Gt of CO2 contains 29.15 Gt of C.

NGC 6712 said:

You effectively ignored the C in the CO2.

A mole of CO2 has a mass of 44g. Of that 44g, 12g is carbon. Therefore the fraction of the mass that is carbon is 12/44 = 3/11 = 0.2727 (or as I left it 1/3.67)

Thus 107 Gt of CO2 contains 29.15 Gt of C.

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Ooops! I see. Thanks.

Katchit said:

Wow, thanks a lot for all the very helpful replies! For some reason i didn't receive an email when your replies came, so please accept my apology for the late reply in thanking you all for your helpful replies and answers

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No problem.

Just divide tons of CO2 by 3.67 to get C or mutliply C by 3.67 to get CO2.