Q1: Humid volume is the total volume in m³ of 1 kg of

ANS:C - gas plus its accompanying vapour at 1 atm. and gas temperature.

"Gas plus its accompanying vapor at 1 atm. and gas temperature" refers to the total volume occupied by a mixture of dry gas and its associated vapor at a specific temperature and pressure. When a gas is saturated with vapor at a given temperature and pressure, it contains both the gas molecules and vapor molecules in equilibrium. The total volume occupied by this gas-vapor mixture includes the volume occupied by the dry gas and the additional volume occupied by the vapor. At 1 atm pressure and the gas temperature, the volume occupied by the gas and its accompanying vapor is determined by the ideal gas law and the vapor pressure of the substance at that temperature. The ideal gas law states that the volume of a gas is directly proportional to its temperature and pressure, assuming constant moles of gas. Therefore, when we refer to the "gas plus its accompanying vapor at 1 atm. and gas temperature," we are considering the total volume occupied by both the dry gas and the vapor it is saturated with, under the given conditions of pressure and temperature. This concept is important in various engineering applications, such as in the design of humidification systems, where the volume of the gas-vapor mixture needs to be taken into account.