What is the formula used for determination of relative viscosity by Ostwald method?

EtoF, P = mass/volume (g cm-3) obtained by multiplying the relative density, of the liquid under examination by 0.998203. The constant (K) of the instrument is determined on a liquid of known viscosity.

What is the formula used for determination of viscosity?

There are several formulas and equations to calculate viscosity, the most common of which is Viscosity = (2 x (ball density – liquid density) x g x a^2) ÷ (9 x v), where g = acceleration due to gravity = 9.8 m/s^2, a = radius of ball bearing, and v = velocity of ball bearing through liquid.

How do you measure viscosity of a viscometer?

Rotational Viscometer Test The torque on the rotating shaft is then used to measure the fluid’s resistance to flow. Since this measurement does not involve the force of gravity but rather a function of the fluid’s internal shear stress, the rotational viscometer calculates the fluid’s absolute viscosity.

What is the working of Ostwald viscometer?

The method of determining viscosity with this instrument consists of measuring the time for a known volume of the liquid (the volume contained between the marks A and B) to flow through the capillary under the influence of gravity. Ostwald viscometers named after the German chemist Wilhelm Ostwald (1853-1932).

How is viscosity measured with an Ostwald viscometer?

Viscosity measurement using ostwald viscometer. According to this law, the rate of flow of liquid through a capillary tube having coefficient ɳ, is given by:- Where, v= volume of liquid in ml t=flow rate in second through capillary r=radius of the capillary in cm l=length of the capillary in cm p=hydrostatic pressure in dyne/sq.

Which is the best method for viscosity determination?

Method A (Using Ostwald-type Viscometer) Apparatus. The apparatus consists of a glass U-tube viscometer (see Fig.) made of clear borosilicate glass and constructed in accordance with the dimensions shown in the figure and in Table 1.

How to calculate viscosity of A Bostwick consistometer?

Clean the Bostwick consistometer with warm soapy water. Dry the instrument completely before using it again. Procedure – Viscometer Method . Turn on the viscometer (Brookfield DV2T) Level the viscometer by adjusting legs until leveling bulb is centered ; Allow the instrument to complete “auto zero” action

How is the viscosity of organic solvents determined?

Bubble viscometer Ostwald viscometer is a commonly used viscometer, which consists of a U-shaped glass tube held vertically. For more accurate measurements it is held in a controlled temperature bath. It is also known as a glass capillary viscometer.