Q1: Gaseous diffusivity at atmospheric pressure is of the order of __________ cm²/second.

ANS:A - 1

Gaseous diffusivity refers to the rate at which a gas can diffuse through another substance, often measured in units of cm²/second. At atmospheric pressure, the diffusivity of gases can vary widely depending on the specific gas and the substance through which it is diffusing. Generally, for common gases such as oxygen, nitrogen, or carbon dioxide diffusing through air or other common substances, the diffusivity at atmospheric pressure falls within the range of 0.1 to 1 cm²/second. Given the options provided:

• 1: This is within the typical range for gaseous diffusivity at atmospheric pressure.
• 1 to 5: This range also encompasses the typical diffusivity values for many common gases.
• 5 to 10: While this range is possible for certain gases and conditions, it's less common for typical atmospheric conditions.
• > 10: Gaseous diffusivity values greater than 10 cm²/second are relatively high and would be less common for most gases at atmospheric pressure.