Question

Which of the following behaviour is true regarding the coefficient of viscosity ( $\eta$ ) of a liquid?

• A. Plot of $\eta$ versus $T$ is linear
• B. Plot of $\eta$ versus $\frac{1}{T}$ is linear
• C. $\eta =\frac{E}{RT}$
• D. Plot log of $\eta$ versus $\frac{1}{T}$ is linear

Answer 1

The correct option is D Plot log of $\eta$ versus $\frac{1}{T}$ is linear

The impact of increasing the temperature of a liquid is to reduce the cohesive forces while simultaneously increasing the rate of molecular interchange.

The former effect causes a decrease in the shear stress while the latter causes it to increase. The result is that liquids show a reduction in viscosity with increasing temperature.