# Please Check My Work :)

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C + O2 →  CO2

mC = 2680 kg = 2680000 g

mO2 =?

mCO2 = ?

MC = 12.01 g/mol

MO2 = 2MO

MO2 = (2)(16.00 g/mol)

MO2 = 32.00 g/mol

MCO2 = MC + 2MO

MCO2 = (12.01 g/mol) + (2)(16.00 g/mol)

MCO2 = 44.01 g/mol

nC = mC / MC

nC = (2680000 g) / (12.01 g/mol)

nC = 223147.3772 mol

nO2 = (223147.3772 mol C) (1 mol O2 / 1 mol C)

nO2 = 223147.3772 mol

nCO2 =  (223147.3772 mol O2) (1 mol CO2 / 1 mol O2)

mCO2 = nCO2 X MCO2

mCO2 = (223147.3772 mol)(44.01 g/mol)

mCO2 = 9820716 g

mCO2 = (9820716 g) / (454 g/lb)

mCO2 = 21632 lbs

Therefore, the mass of CO2 produced from coal is 21632 lbs every year per person.

m = mass

M = molar mass

n = number of moles

I am just a little thrown off by the fact that there isn't a limiting or excess reactant in this question. Every example I've done in class and in homework has included one. Since there isn't a limiting reactant, can I use the n-value of either carbon or oxygen to determine the n-value for carbon dioxide (since they're the same values)? I have 2 more questions like this that need to be checked if you guys are bored, let me know if that interests you!

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43 minutes ago, Kagi98JP said:

C + O2 →  CO2

mC = 2680 kg = 2680000 g

mO2 =?

mCO2 = ?

MC = 12.01 g/mol

MO2 = 2MO

MO2 = (2)(16.00 g/mol)

MO2 = 32.00 g/mol

MCO2 = MC + 2MO

MCO2 = (12.01 g/mol) + (2)(16.00 g/mol)

MCO2 = 44.01 g/mol

nC = mC / MC

nC = (2680000 g) / (12.01 g/mol)

nC = 223147.3772 mol

nO2 = (223147.3772 mol C) (1 mol O2 / 1 mol C)

nO2 = 223147.3772 mol

nCO2 =  (223147.3772 mol O2) (1 mol CO2 / 1 mol O2)

mCO2 = nCO2 X MCO2

mCO2 = (223147.3772 mol)(44.01 g/mol)

mCO2 = 9820716 g

mCO2 = (9820716 g) / (454 g/lb)

mCO2 = 21632 lbs

Therefore, the mass of CO2 produced from coal is 21632 lbs every year per person.

m = mass

M = molar mass

n = number of moles

I am just a little thrown off by the fact that there isn't a limiting or excess reactant in this question. Every example I've done in class and in homework has included one. Since there isn't a limiting reactant, can I use the n-value of either carbon or oxygen to determine the n-value for carbon dioxide (since they're the same values)? I have 2 more questions like this that need to be checked if you guys are bored, let me know if that interests you!

Well, actually, checking homework is not my absolute favourite pastime.......

This all looks fine to me. You are not doing a reaction with an excess of one of the reactants here, so don't worry about that. I assume from your comments at the end that 2.68 metric tonnes of coal is burnt per person per year in your country. I assume this is the US, as you have had to convert to the old Imperial units at the end - something we gave up in Britain when I was at school in the 1970s.

And yes you have one mole of carbon reacting with one mole of diatomic oxygen molecules to make one mole of CO2.

My only comment on your working is that you may find it better, soon, to start getting used to standard form (exponential or scientific notation) to express the numbers, to get rid of all these zeros which can become easy to miscount. So 2680kg = 2.68 x 10³ kg = 2.68 x 10⁶ g. But maybe you have not come to that yet.

You seem to know what you are doing so have confidence in your other calculations. I expect you have got them right.

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24 minutes ago, exchemist said:

Well, actually, checking homework is not my absolute favourite pastime.......

This all looks fine to me. You are not doing a reaction with an excess of one of the reactants here, so don't worry about that. I assume from your comments at the end that 2.68 metric tonnes of coal is burnt per person per year in your country. I assume this is the US, as you have had to convert to the old Imperial units at the end - something we gave up in Britain when I was at school in the 1970s.

And yes you have one mole of carbon reacting with one mole of diatomic oxygen molecules to make one mole of CO2.

My only comment on your working is that you may find it better, soon, to start getting used to standard form (exponential or scientific notation) to express the numbers, to get rid of all these zeros which can become easy to miscount. So 2680kg = 2.68 x 10³ kg = 2.68 x 10⁶ g. But maybe you have not come to that yet.

You seem to know what you are doing so have confidence in your other calculations. I expect you have got them right.

Thank you so much! I'll definitely make the change over to scientific notation. I am just so hell-bent on visualizing everything that it'll take a bit of practice. Have a great day!

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Ah man then you should learn LaTex. You can visualize all the math with it

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