Question

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

Answer 1

ANSWER :

It is not clearly visible and hence it gets difficult to check the phase boundaries.

Explanation:

Here, as we have colourless liquid it is easy to see the boundaries (phase boundary) no matter whether it is convex or concave thus we considered the lower meniscus in the colourless liquid.

IN GENERAL TERM

The meniscus is the curvature of the water surface. The water in the tube gets stuck to the boundaries only.

Therefore : A student must measure at the lowest point.

But in the coloured liquid as here it coloured all the outside area and ultimately it gets difficult to check the phase boundaries thus here it is not possible to measure from lower men

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...