Mercury has an angle of contact equal to 140° with soda lime glass. A narrow tube of radius 1.00 mm made of this glass is dipped in a trough containing mercury. By what amount does the mercury dip down in the tube relative to the liquid surface outside ? Surface tension of mercury at the temperature of the experiment is 0.465 N m–1. Density of mercury = 13.6 × 103 kg m–3
Mercury has an angle of contact equal to 140° with soda lime glass. A narrow tube of radius 1.00 mm made of this glass is dipped in a trough containing mercury. By what amount does the mercury dip down in the tube relative to the liquid surface outside ? Surface tension of mercury at the temperature of the experiment is 0.465 N m–1. Density of mercury = 13.6 × 103 kg m–3

According to the question, the density of mercury is

ρ =13.6 × 103 kg/m3

Acceleration due to gravity, g = 9.8 m/s2
The angle of the contact between mercury and soda-lime glass is

θ = 140°
The surface tension of mercury at the given temperature

s = 0.465 N m-3
The radius of the narrow tube is

r = 2/2  = 1 mm = 1 × 10-3 m
Let h represent the dip in the depth of mercury. Therefore, we can write the expression of surface tension as follows :    The negative indication indicates that the mercury level is dropping. As a result, the mercury drops by 5.34 mm.