convert the height of water column in the gas measuring tube into mmHg. The density of mercury is 13.6g/ml...

Question

and the height of water column in the gas measuring tube is 16.3 cm?

Answer 1

The density of Hg (mercury) is 13.6 that of water so the height measure with Hg is 13.6 less than height measured in water

In water the height is 16.3 cm = 163 mm

so the height in mm mercury is 163/13.6 = 12 mm Hg

Answer 2

Hi, If I am correct in thinking that you have a beaker of mercury and a long tube with one end immersed and another end attatched to a syringe then provided that you do not let go, the syringe will eventually suck the mercury all the way up. If you are askig what happens if you put an empty tube with one end closed into a beaker of mercury then it will rise to 760 mm due to atmospheric pressure. This can be verified using the approximate formula pressure=densityxgravityxheight and saying the pressure is atmospheric, density is that of mercury and use 9.81 for the gravity however you will need to use the pressure in Pa and density in Kgm^-3 for this to give you a height in meters using this value of g. This problem is known as the Florentine well problem and was first solved many years ago by torricelli who was one of galileo's students if you are interested.