Question

What is the pressure (in atmospheres) of the gas inside the container connected to an open-end, mercury-filled manometer as shown in the picture? The atmospheric pressure is 0.95atm.
l----l |
(G) l |
l - ---
l Hg
l Hg *18cm
- - ---
Hg Hg
HgHgHgHg
what process do I use to solve for this problem? lost, tried and it didn't work out.


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Chemistry - leo, Saturday, October 20, 2007 at 10:45pm

the picture didn't work. it is U shaped with a bulb of some random gas on one end (the left),Hg in the middle and an open end. The distance between the Hg, under the open air portion, is 18cm, which is before the bottom of the U. Does that make sense. Basically a manometer.

Answer 1

I don't decipher the picture. If the mercury is moved upward, then...

Pressuregas= pressureHg+atmospheric pressure.

Now pressure Hg is the distance from the low Hg level to the high Hg level. Watch your units.

Answer 2

do I just change the 18cm's to 180mm to help work this out?
Would it look something like this:
Pressure gas = 180mmHg+0.95atm/760mmHg?
180.95mmHg/760mmHg = 0.238atm??
I think I am way off.

Answer 3

yeah your off...180 mmHg is not the gas pressure. Instead, 180 mmHg is the difference between the gas pressure and the atmospheric pressure. i have the same problem...and i cant figure it out! your on the right track though!

Answer 4

its 180/760+.95

Answer 5

180/760 gives the DIFFERENCE between the atmospheric pressure and the pressure in the container in mmHg's.

The container pressure is higher than the atmospheric pressure so add the difference to the container pressure.

Answer 6

(180/760)+(0.95)

Answer 7

This man speaks the truth!

Answer 8

Hey corey, how did you figure that out?

Answer 9

The difference between mercury levels is 18 . Convert this value to millimeters.

Answer 10

It's 1.19.
18-> 180
180/760-> 0.236842
0.95+ 0.2368 ~ 1.19 atm