Question

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? The surface tension of mercury at the temperature of the experiment is 0.465 N m. Density of mercury = 13.6 × 103 kg m-3 .

Answer 1

Angle of contact θ = 140°

Radius of the tube, r = 1 mm = 10-3m

Surface tepsion of mercury * = 0.465 N/m

Density of mercury, ρ = 13.6 × 103 kg/m3

g = 9.8 m/s2

Let the Dip in height of mercury be h Surface tension is given by,

Negative sign indicates that mercury level, dips by 5.34 mm.