Capillary Rise and Pressure in Sealed Capillary Tubes

[zorro]

Will there be any difference in capillary rise if the capillary tube is sealed at one end?
What is the value of pressure at a point in the capillary tube on the same horizontal level as that of liquid outside? - Is it equal to the atmospheric pressure + the height of liquid column above it?

 

[Eynstone]

Practically, no difference will be observed because the surface tension doesn't vary.

 

[K^2]

There will be a difference if there is gas trapped above the fluid. The pressure in the gas will reduce the hight of capillary column.

It isn't entirely correct, but you can usually think of capillary effect and osmotic pressure as actual contributions to pressure, then you just solve until pressures equalize. So you have pressure from the fluid column pulling it down plus the external pressure doing the same. You have pressure in the fluid (E.g. atmospheric pressure, if there is an opening somewhere) and capillary effect pushing fluid up. Find a point where they all balance, and you are done.

If the capillary tube is open and the container with fluid is exposed to atmosphere, then you have the atmospheric pressure balance itself above and bellow your column. Then all you have to do is compare pressure from column's height to effective "negative" pressure generated by the capillary effect. If you close one end, or you close the container with fluid, you have to take that into account.