Q1: Viscosity of gases __________ with increase in temperature.

ANS:B - increase slowly

When we say that the viscosity of gases "increases slowly" with an increase in temperature, we mean that the viscosity does indeed increase, but the rate of increase is relatively gradual compared to some other materials, such as liquids. The reason for this behavior is related to the kinetic theory of gases. As the temperature of a gas increases, the average kinetic energy of its molecules also increases. This leads to an increase in the speed and randomness of molecular motion within the gas. While it might seem counterintuitive that increased molecular motion could lead to an increase in viscosity, the key factor here is the nature of gas molecules. In a gas, molecules are relatively far apart and experience weak intermolecular forces compared to liquids or solids. Therefore, the effect of increased molecular motion on viscosity is not as pronounced in gases as it is in liquids. Additionally, the increase in temperature causes gas molecules to collide more frequently and with greater energy. This increased collision frequency can contribute to a slight increase in the viscosity of the gas. However, because of the weak intermolecular forces and the relatively large distance between molecules in a gas, the increase in viscosity is typically gradual and slower compared to the increase seen in liquids or solids with temperature. Therefore, we describe the increase in viscosity of gases with temperature as "increasing slowly."