Question

33 POINTS PLEASE HELP. A mixture of hydrogen and oxygen gases has a total pressure of 5.50 atm. What is the partial pressure of the hydrogen if the P (O2) = 1250 mm Hg?

Answer 1

Again the use of mm∙Hg of mercury to express a pressure OVER 1∙atm is a bit troubling to me. And I wonder if it is taught in your syllabus. Now 1∙atm will support a column of mercury that is 760∙mm high…so I suppose the pressure measurement is

pdioxgen=
`(1250∙mm∙Hg)/(760∙mm∙Hg∙atm−1)` = =1.64∙atm

pdihydrogen=5.50∙atm−1.64∙atm=3.86∙atm

The pressure are additive …. see Dalton’s law of partial of pressures …. in a gaseous mixture the partial pressure exerted by a gas is the same as the pressure it would exert if it alone occupied the container …. the total pressure is the SUM of the individual partial pressures.

Do they show you a mercury manometer in the lab? I am guessing not …. they would not let me set one up in the teaching lab, because of legitimate safety concerns…

Answer 2

2930 mmHg

Step-by-step explanation:

We need to convert these two different units of pressure into the same. Let's just use mmHg. So, we need to go from atm to mmHg. The conversion factor is 1 atm = 760 mmHg. We have 5.50 atm, so multiply 760 by 5.50: 4180 mmHg.

Now, partial pressure means that the pressures of each of the different gases will add up to the total pressure. Here, our total pressure is 4180 mmHg and the pressure of oxygen is 1250 mmHg. So to find the pressure of hydrogen, we simply subtract 1250 from 4180: 4180 - 1250 = 2930 mmHg.

Hope this helps!