Question

Always take the zero mark of lower meniscus as the starting point for every titration. Give reason.

Answer 1

Answer:

The zero mark of the lower meniscus is considered while titrating.

A meniscus refers to the curvature of the water surface. Water has a tendency to "stick" to the walls of the graduated cylinder, but on the sides and not the middle.  

Hence, the water level does not look straight when the students look at the level. Therefore, the water level must be measured at the lowest mark for colorless liquids.  

Explanation:

Answer 2

Dear Student,

◆ Lower meniscus of liquid level is taken as zero mark for every titration because -

• When a solution is taken in titrating tube, some of it sticks to the edges due to adhesive forces.
• But the actual phase boundary between solution and air is defined by lower meniscus of liquid.
• Hence, always take the zero mark of lower meniscus as the starting point for every titration.

Thanks dear. Hope this helps you...