How do you calculate viscosity by Ostwald viscometer?
BACKGROUND
- Ostwald viscometer is used to determine viscosity of Newtonian fluid.
- η1 can be determine using following equation.
- η1=ʆ1t1/ ʆ2t2 X η2
- ʆ1=Density of unknown liquid.
- t1 =Time of flow of unknown liquid.
- ʆ2 =Density of standard liquid.
- t2 =Time of flow of standard liquid.
- η2=Viscosity of standard liquid.
How is viscometer constant calculated?
The calibration constant for the viscometer at 100°C can now be calculated using the same equation. Viscometer No. (cP) multiply the kinematic viscosity in mm2 /s( cSt) by the density in grams per milliliter. shown below are based on a coefficient of thermal expansion typical to that for a mineral oil.
What is the formula used for determination of relative viscosity by Ostwald’s method?
η=KL/w, Where, L = the angular momentum in Newton meters, w = the angular speed in radians per second.
What is the formula for calculating 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 find the viscosity of a viscometer?
in milligrams per cubic millimetre, obtained by multiplying its relative density ( ) by 0.9982, t = flow time, in seconds, of the liquid to be examined. The constant k is determined using a suitable viscometer calibration liquid. To calculate the kinematic viscosity (mm2·s− 1), use the following formula: v = kt.
How do you calculate relative viscosity?
Dividing the viscosity of the polymer solution (η) by the viscosity of the pure solvent (ηο) gives the relative viscosity with the dimensionless unit. Equation 7: Relative viscosity is the viscosity of the polymer solution divided by the viscosity of pure solvent. Molar mass (molar mass is given as g/mol in most cases.
What is the formula for fluid?
The volume of a portion of the fluid in a pipe can be written as V = A d V=Ad V=AdV, equals, A, d, where A is the cross sectional area of the fluid and d is the width of that portion of fluid, see the diagram below.
What is the formula for viscosity of a liquid?
The dimensional formula of viscosity is [ML-1T-1]. The viscosity of liquids decreases rapidly with an increase in temperature, and the viscosity of gases increases with an increase in temperature. Thus, upon heating, liquids flow more easily, whereas gases flow more slowly.
What is the formula of dynamic viscosity?
The units of dynamic viscosity are: Force / area x time The Pascal unit (Pa) is used to describe pressure or stress = force per area This unit can be combined with time (sec) to define dynamic viscosity.
How do you calculate kinematic and dynamic viscosity?
Density actually provides a way to convert between a kinematic and a dynamic viscosity measurement. The formula for the conversion is: Kinematic (cSt) x Density = Dynamic (cP)
What is kinematic viscosity unit?
The kinematic viscosity [m2/s] is the ratio between the dynamic viscosity [Pa. s = 1 kg/m·s] and the density of a fluid [kg/m3]. The SI unit of the kinematic viscosity is m2/s. Other units are: 1 St (Stoke) = 1 cm2/s = 10−4 m2/s.
¿Quién inventó el viscosímetro?
Este viscosímetro fue nombrado en honor al químico alemán Wilhelm Ostwald, nacido el 2 de septiembre de 1853, que ganó el Premio Nobel de Química en 1909 gracias a su trabajo en la catálisis y diferentes investigaciones que promovieron diferentes principios.
¿Cómo se clasifican los viscosímetros?
Tales viscosímetros pueden clasificarse como de flujo directo o de flujo inverso. Los viscosímetros de flujo inverso tienen el depósito por encima de las marcas, y los de flujo directo son los que tienen el depósito por debajo de las marcas.
¿Cómo medir la temperatura de un viscosímetro?
El viscosímetro en primer lugar tiene que estar completamente seco, una ves seco se vierte la muestra liquida a estudiar aproximadamente 7 mL, el viscosímetro se coloca en el recipiente con baño maría y se empieza a medir la temperatura, primero con 20 °C, luego con 30 °C y finalmente con 40 °C.
¿Quién es el padre del viscosímetro?
El padre de este viscosímetro fue Wilhelm Ostwald. Nacido en Riga, Letonia, estudió química en la Universidad de Dorpat (ahora Tartu, Estonia) y, después de obtener su doctorado, ascendió rápidamente de rango para convertirse en profesor de química física en el Politécnico de Riga en 1881.