Answer :
Final answer:
The difference in the rise and fall of water and mercury in a capillary tube is 12.4 cm, with water rising 9 cm and mercury falling 3.4 cm. This effect is due to the interplay of adhesive and cohesive forces and their impact on capillary action.
Explanation:
The difference in the rise and fall of water and mercury in a capillary tube can be found by simply subtracting the height of one from the other. Water rises to a height of 9 cm while mercury falls to a depth of 3.4 cm. The difference between the two is 9 cm (rise) + 3.4 cm (fall) because the fall of mercury adds to the overall difference in their levels.
The total difference in the rise and fall is therefore 9 cm + 3.4 cm = 12.4 cm. This can be understood considering that capillary action depends upon the interplay of adhesive and cohesive forces present in liquids, with the rise or fall of the liquid in the capillary tube being directly proportional to its surface tension and inversely proportional to its density and the radius of the capillary tube.
