The greatest pressure of the following is that exerted by:

(a) a column of Hg 75.0 cm high (d=13.6 g/cm^3)
(b) 10.0 g H2 gas at STP
(c) a column of air 10 miles high; or
(d) a column of CCl4 60.0 cm high (d=1.59 g/cm^3)
The answer is b. I know that pressure=force/area and pressure can be atm or torr or bar. (c) is 1013 mb. Not sure the reasoning process here with the rest and how to compare with each other. thank you.

1 answer

a) is 75/78 = <1 atm
b) If the H2 gas is at STP then P MUST be 1 atm.
c) An air column to infinity is 1 atm so 10 miles high will be <1atm. (1013 mb is 0.99 atm)
d)Here is a link to calculate P of CCl4 column. It is < 1 atm.
(Broken Link Removed) b must the right answer.