K.C.S.E Physics Q & A - MODEL 2013PP1QN11

K.C.S.E Physics Q & A - MODEL 2013PP1QN11

​ Figure 6 (a) and 6(b) show capillary tubes inserted in water and mercury respectively.

It is observed that in water the meniscus in the capillary tube is higher than the meniscus in the beaker, while in mercury the meniscus in the capillary tube is lower than the meniscus in the beaker. Explain these observations. 

answer

•  Water molecules have a high adhesion forces; With glass molecules arid hence rise up the tube while mercury molecules have greater cohesion;
• Forces within than adhesion with glass hence do not rise up.