Question

What is the angle of contact of mercury with glass?

Answer 1

It is greater than 90 degrees and its obtuse .The shape of meniscus is convex.The level of liquid decreases.The exact value is 135 degree

Answer 2

$\huge \text{Angle\: Of\: Contact }$

✿ It is the angle between the tangent drawn to the liquid surface at the point of contact and the solid surface within the liquid.

✿ The angle of contact is acute (<90°) for concave meniscus .The liquids having acute angle wets the surfaces, which are in contact. The angle of contact between ordinary glass and ordinary water is acute. It is about (8°).

✿ The angle of contact is obtuse (>90° and <180°) for convex meniscus. The liquid having obtuse angle does not wet the surfaces. The angle of contact between Mercury and any surface is obtuse. (It is about 135°)

✿ The angle of contact can have any value between 0 and 180 .

✿ The angle of contact between smooth glass surface and pure water is zero.