What is the size difference between Hydrogen and Oxygen

notsoround

Hi
I would like to know What the size difference ratio between Hydrogen and Oxygen gas atoms, in the form of the following question...'


If i had two identically separate 1 liter containers, (one containing Hydrogen, and the other Oxygen), at the very same pounds psi, Which container has more atoms in it , and at what ratio?


Great forum!!
Thank you very much!

Integral

You need to show us some of your thought processes. What do you know that might help you answer this question?

zaldar

think about moles, and think about what you know about the avagodro's law of gases.

notsoround

Thank you for your reply, and after going over Avagodro's law and moles, i did the following 2 calculations for H2 and O2 molecules. Please confirm or oppose my results...

(using grams, 1kg or 1000g)

I divide by the molar mass (1.0079g/mole) to get 992.2 moles of hydrogen. I then multiply by Avagadro's number, 6.0221415x10^23. That gave me 5.975x10^26 atoms in a 1kg sample of hydrogen.

-vs-

O2 1000g x (1 mol/ 32 g ) x (6.022 x 10^23) = 1.92 x 10^28 molecules O2 times by 2
1.92 x 10^28 x 2 = 3.85 x 10^28 atoms in a 1kg sample of Oxygen


So if my conclusions are correct...
3.85 x 10^28 atoms of O is > 5.975x10^26 atoms of H, So H atoms take up more physical space than O atoms under the same conditions, hence the Oxygen tank (from the initial question) has more actual atoms. ???

ehild

The problem says two identical 1 liter container. Why do you think that there are 1 kg gas in each?

ehild

notsoround

Integral "You need to show us some of your thought processes. What do you know that might help you answer this question?"
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I am brand new to this. Business is more my specialty. I am completely fascinated, and believe i have found a new passion. I really appreciate this site and all your experienced feedback.
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ehild "The problem says two identical 1 liter container. Why do you think that there are 1 kg gas in each?"



Well, the tanks and their PSI are theoretical at this point. They could be any size. I attempting to understand how to formulate this kind of calculation. As i have never done this kind of calculation. But with the right mentor('s), im a quick learner!

Figuring 1 kilogram = 1.04 liters, Would my calculations make sense if i said the tanks were exactly 1.04 liters?

NascentOxygen

Passion is good. Google is good. You need to google "Avogadro's hypothesis".

ehild

No, liter is unit of volume, kg is unit of mass. You know how big is a one-liter bottle? If it is filled with water, the mass of water is about 1 kg. The mass contained in 1 liter volume depends on the density of the substance. The density of water is about 1kg/liter, that of a gas is of the order 1 kg/m^3, that is 0.001 kg/liter.
The difference between liquids and gases is that the molecules of a liquid touch each other, so their size determines the volume the liquid occupies. The molecules of a gas are free to move and are much farther from each other than their size.
You get the number of moles of a gas like oxygen and hydrogen in a given volume at room temperature or higher by using the ideal gas law, PV=nRT. P is the pressure, V is the volume, T is the absolute temperature, R is a constant and n is the number of moles. You see that n does not depend of the kind of the gas.

ehild

NascentOxygen

I surmise that the OP may have abandoned his quest for the comparative sizes of some gaseous molecules, but if still reading, I suggest that you surf to http://ask.com and type in the question: What is the size of an oxygen molecule? You will be presented with myriad links to articles guaranteed to pique your interest.