Chemistry problem

[Jeros]

im stuck on this question:

Calculate the mass of carbon dioxide which will be produced if 100g of carbon is burned in oxygen.

C+O2 = CO2

Im thinking that if 100g of C is 8.333 moles im going to need 2 oxygen moles for every 1 mole of C reacted so i will need 16.666 moles of O for the reaction which gives me 24.933 moles of CO2 produced (we are assuming this is perfect reaction) , CO2 has a molar mass of 44g so its 24.933x44 giving me 1097.152g of CO2 produced

amirite folks?

 

[swords]

molecular mass of carbon = 12

1M C = 12g
100g/12g= 8.33333333333333333333 M (tick)

the question is about the complete combustion of carbon in oxygen, so assume 100% efficiency. (tick)

molecular mass of oxygen = 16

stoichiometry of C:O = 1:2 (tick)

so 8.333333333333333333333 * 2 = 16.6666666666666666666666 (tick)

8.333333333333333333333 + 16.66666666666666666666666666 = 24.9999... moles

12+(16*2)=44 so 1M CO2 = 44g

44*24.999999999999999 = 1100g CO2 so 1.1kg.

Almost right, you added the moles together wrong for some reason...

 

[Cadelin]

Um no.....

You have 8.33 Moles of carbon.
You need 16.67 Moles of oxygen.

8.33 * 12 + 16.67 * 16 = 366.67 g

If you want to do it with the molar mass of C02 you only have 8.33 Moles of C02 (because you only have 8.33 Moles of carbon to start off with)

8.33 * 44 = 366.67 g

 

[Jugvayne]

Cadelin, your answer is right but the way you've gotten to it is wrong.

The stocheometry is 1:1 as it's diatomic oxygen as opposed to monoatomic oxygen, therefore the molar mass of O2 is 32. Therefore, you need 8.33 moles of O2.

So 8.33*12 + 8.33*32 = 366.7g

 

[old.Osy]

Not funny.

 

[swords]

Bah!
Now there's going to be more people doing science correctly!
You do know that we need to give false information to ensure the newspapers can moan about how shit we are at sciences.
Oh and it's important that the exams are dumbed down every year relative to previous years to ensure the papers can moan about that too...

Now the exams will have to get harder to compensate

 

[Access Denied]

That all just went straight over my head

I know enough chemistry to make stuff that goes boom. All I need =P