VISCOSITY OF LIQUID for 1st sem By Vinod kumar mulge Department of chemistry

VISCOSITY OF DOUBLE LIQUID   DETERMINATION OF THE TWO LIQUIDS USING OSTWALD VISCOMETER [ DENSITIES ARE TO BE SUPPLIED ] REQ; 1] ostwalds viscometer 2] stop watch 3] pipetta 4] liquid A 5] liquid B 6]distilled water etc PROCEDURE; Clean the Ostwald viscometer with hot cromic acid [cleaning solution ] and rinse with disstiled water repeatedly .pipettee out a known volume volume [15 ml] of distilled water that will fill volume between A and B of viscomer and at the same time occupy a lower third of bottom bulb clamp the viscometer vertically in a constant tempature bath so that the feed bulb is under surface. Allow the water in the viscometer to come to thermal equilibrium. Attach ab short length of rubber tubing to the viscometer arm so as to the feed bulb allow the water thus drawn to run down freely note the time the upper meniscus takes to more from the mark A to B . Reapeat the readings 1 to 3 times . remove water and rinse with the test liquid whose viscosity is to be determined . Reapet the measurement with the test liquid by pipetting the same volume of liquid as that of water into the viscometer by knowing the density and absolute viscocity of water . We have to find the relative viskocity of the liquid . Repeate the procedure for the determination of the vicocity of a second liquid .

nl = dl + tl /dw tw ×nw Obs no LIQUID TIME FLOW [IN SEC] DENSITY d VISCOCITY nl = dl + tl /dw tw ×nw 1 2 3 MEAN 1 . A 2 . B 3 . WATER

Calculation The viscocity of a liquid can be determined by using the relation nl = dl + tl /dw tw ×nw Where tl is the time flow of liquid tw is time flow of water dl density of liquid dw is a density of water and nw viscocity of water