Question

1. the shape of the meniscus of water in a glass tube is different from that of mercury in a glass tube. why? h2o in glass hg in glass

Explanation:

The difference is due to adhesion and cohesion forces. Water has stronger adhesion to glass (polar - polar interaction as glass has polar sites and water is polar) than cohesion between water molecules, causing a concave meniscus. Mercury has stronger cohesion between its atoms (due to metallic bonding) than adhesion to glass, resulting in a convex meniscus.

Answer:

The difference in meniscus shapes is because water has stronger adhesion to glass than cohesion within itself, while mercury has stronger cohesion within itself than adhesion to glass.