Question

How determined the viscosity of ethanol with the help of Ostwald viscometer

Answer 1

Answer: The viscosity of ethanol can be determined with the help of viscometer.

Explanation:

Viscosity of ethanol can be determined with the help of Ostwald Viscometer. Water is sucked to level A and then duration of time taken by water to reach level B under the influence of gravity is recorded. The same procedure is followed with ethanol.The following formula is used for the calculations:

$\eta_2=\eta_1\frac{\rho_2T_2}{\rho_1T_1}$       .....(1)

From the above equation, taking sample 1 to be known that is water, we can determine the viscosity of sample 2 that is ethanol.

$\eta_1=\text{Viscosity of water}=1\text{ centi Poise}$ (known)

$\rho_1=\text{Density of water}=1g/cm^3$ (known)

$T_1$ =Time taken by the water to flow down from level A to level B. (Experimentally determined)

$\eta_2=\text{Viscosity of ethanol}=?\text{ centi Poise}$  

$\rho_2=\text{Density of ethanol}=0.789g/cm^3$ (known)

$T_2$ = Time taken by the ethanol to flow down from level A to level B. (Experimentally determined)

From the above known values, we can determine the value of viscosity of ethanol using equation 1.