How Many Molecules of CO2 and Water Vapour Are in 1 Cubic Metre of Air?

[alytal]

One cubic metre (1 m3) of atmosphere at sea level contains 3.80 × 102 ppm of CO2 and 5.00 × 103 ppm of water vapour.
If there is a total of 2.6 × 1025 molecules in 1 m3 of air, calculate how many molecules of CO2 and water vapour there are in 1 m3 of air??

I just starting studying science and i´m stuck with this simple question..please help!

 

[sjb-2812]

One cubic metre (1 m³) of atmosphere at sea level contains 3.80 × 10² ppm of CO₂ and 5.00 × 10³ ppm of water vapour.
If there is a total of 2.6 × 10²⁵ molecules in 1 m³ of air, calculate how many molecules of CO₂ and water vapour there are in 1 m³ of air??

I just starting studying science and i´m stuck with this simple question..please help!

What does 3.80 × 10² ppm mean?

 

[alytal]

What does 3.80 × 10² ppm mean?

it means 380 ppm (parts per million)

 

[sjb-2812]

it means 380 ppm (parts per million)

So, if you had a million cubic metres of atmosphere, how much of that would be carbon dioxide?

 

[alytal]

So, if you had a million cubic metres of atmosphere, how much of that would be carbon dioxide?

380 molecules of co2...is that simple the answer??

 

[sjb-2812]

380 molecules of CO₂...is that simple the answer??

No, not to the question I posed. 1 molecule does not occupy 1 m³.

However, if you had a million molecules, then yes, for this sample you would have 380 molecules of carbon dioxide. Now, how many times larger is 2.6 × 10²⁵, compared to 1 million; or if you prefer how many millions are there in a sample that size?

 

[alytal]

No, not to the question I posed. 1 molecule does not occupy 1 m³.

However, if you had a million molecules, then yes, for this sample you would have 380 molecules of carbon dioxide. Now, how many times larger is 2.6 × 10²⁵, compared to 1 million; or if you prefer how many millions are there in a sample that size?

So... (380 x 1025) / 10^{6 = 988 x 10[19] ??
I´m very bad..i know...}

 

[sjb-2812]

Not quite, how many millions are there in 2,000,000?

 

[alytal]

Not quite, how many millions are there in 2,000,000?

two...

 

[sjb-2812]

How many millions in 5 x 10⁹?