00:01
So to begin this problem, letter a wants to write the balanced chemical formula, which is 2h2 -2, goes to 2h2 plus o2.
00:16
Letter b wants the vapor pressure of water, h2o, at 25 degrees celsius.
00:26
And so looking that up in a table will tell you it's 23.
00:35
Now the letter c, i'll go to a new page here.
00:39
Letter c wants the partial pressure of o2.
00:44
And so we can use the equation p total is ph2 plus p -o2 and rearrange this to solve for p -o2.
00:57
So p -o2 is p -total minus ph2 and p -total.
01:06
Is given as 763 .8 tor or millimeters of mercury, they translate to the same value, and then subtract that from the 23 .8 tour, excuse me, found in the, in letter b.
01:29
And so when this is done, we find the partial pressure of oxygen to be 740 tour.
01:37
Letter d, letter d, wants to find the number of moles of oxygen.
01:44
And so to do that, we can use the ideal gas law, pv equals nrt, and rearrange it to solve for n.
01:51
So n equals pv over rt.
01:56
Our pressure is given as 0 .973, 0 .97368 atmospheres, which is taking the pressure in tor from letter c, and dividing it by 760 to convert to atmospheres...