Viscosity of gases ______ with temperature, whereas viscosity of liquid _____ with temperature.

Viscosity of gases generally decreases with temperature, whereas viscosity of liquids tends to increase with temperature.

In gases, as the temperature increases, the kinetic energy of the gas molecules also increases. This increased kinetic energy leads to more frequent and energetic collisions between the gas molecules, causing them to move more freely and reducing the resistance to flow. Consequently, the viscosity of gases decreases as the temperature rises.

In liquids, the situation is different. As the temperature increases, the average kinetic energy of the liquid molecules also increases. This heightened molecular motion results in more frequent and vigorous intermolecular interactions, such as molecular collisions and attractive forces. These interactions impede the flow of liquid and make it more resistant to deformation, thereby increasing its viscosity with rising temperature.

It's important to note that the relationship between temperature and viscosity can vary depending on the specific properties of the gas or liquid in question. Additionally, for liquids close to their boiling point, the trend may reverse due to changes in the liquid's state from liquid to gas.