maths question

buachaillbeoir

ok so heres the question, i cant for the life of me work it out, any ideas

i need to find out how many molecules of CO2 there are in a cubic metre of air from a particular year.
there is 280 parts per milion co2 in atmosphere
2.6x10*25 molecules per m3 of air at sea level
calculate the number of molecules of CO2 in each cubic metre of air

any help, even with the above would be greatly appreciated

locum-motion

buachaillbeoir wrote: »

ok so heres the question, i cant for the life of me work it out, any ideas

i need to find out how many molecules of CO2 there are in a cubic metre of air from a particular year.
there is 280 parts per milion co2 in atmosphere
2.6x10*25 molecules per m3 of air at sea level
calculate the number of molecules of CO2 in each cubic metre of air

any help, even with the above would be greatly appreciated

Isn't it:

2.6 x 10^25 / 1,000,000 x 280

= 2.6 x 10^19 x 280

= 728 x 10^19

= 7.28 x 10^21

?

Mellor

I have no background in chemistry, but this appears pretty basic.

Air has 2.6x10*25 molecules/m^3
280/million are CO2

(2.6x10*25)*280/1,000,000 =
(2.6x10*21)*2.8=
7.28x10*21


Or am I messing up totally?
(edit: probably not, as I got the same as above)

bnt

The above will work if "parts per million" refers to numbers of molecules. If it's by weight, that complicates matters - you'd need to work out the molecular masses or CO2 versus the atmosphere and factor those in.