With a neat labelled diagram, explain concave meniscus - acute angle of contact.

A concave meniscus, the molecules of the liquids have a lesser attraction to each other (cohesion) than molecule-container attraction (adhesive forces). In this case, the film of liquid at the top of the surface will bend upwards near the sides of container. eg. Water

So here angle of contact θ is acute.

A convex meniscus occurs when the molecules of the liquids have a stronger attraction to each other (cohesion) than molecule-container attraction (adhesive forces).  In this case, the film of liquid at the top of the surface will bend downwards near the sides of container. eg. Mercury

Regards