Talking about end point ted..we normally add excess indicator say 7-10 drops to easily notice the change of color..I presume the end point is the one that the color after adding the titrant does reverses back to its previous color..

I refrain from letting it boil for the reason that the clinker particles usually sticked to the flask, I assumed its not correct..

Hello Norew,

Yes, the end-point is considered to be the first faint, permanent, pink colour obtained by dropwise addition of the titrant.

With regard to boiling, if you mean sticking to the sides of the flask above the level of the solution, the use of a reflux condenser attached to the top of the flask will prevent this happening because the returning alcohol should wash back any small particles of clinker that may stick to the sides of the flask.

Regards,

Ted.