While reading about capillary action in my chemistry textbook, I learned about what causes a convex and a concave meniscus. To my understanding, a concave meniscus forms when the adhesive force between the solution and the capillary is larger than between the solution molecules themselves e.g. between water and a glass capillary. A convex meniscus forms when the cohesive forces of the solution is larger than the adhesive forces between the solution and the capillary e.g. between mercury and the glass capillary tube.

 

My question is why is water so strongly attracted to glass then between itself?

Hi, welcome here!

 

Silica and glass surfaces have a layer of hydrates, typically ending as Si-O-H. The Si-O bond must make this oxygen atom more favourable than in a water molecule for hydrogen bonds with other water molecules.