The vapor pressure is the pressure of the vapor phase of a substance when it is in equilibrium with the solid or liquid phase of the substance. The relative humidity is the partial pressure of water vapor in the air divided by the vapor pressure of water at that same temperature, expressed as a percentage. The air is saturated when the humidity is 100%. (a) The vapor pressure of water at 20.0°C is 2.34 × 10³ Pa. If the air temperature is 20.0°C and the relative humidity is 60%, what is the partial pressure of water vapor in the atmosphere (that is, the pressure due to water vapor alone)?

Problem 3. The viral coefficients of a gas at 20 °C and 11.5 bar are B = -138 cm³ mol¹ and C=7222 cmº mol². Calculate the V (molar volume) Z (compressibility factor) of the gas. Use the equation below (R = 83.14 cm³ bar mol-¹ K-¹). PV 2 = ² = (1 + = + =) Z RT

Two containers of equal volume each hold samples of the same ideal gas. Container A has 2 times as many molecules as container B. If the gas pressure is the same in the two containers, find the ratio of the the absolute temperatures TA and TB ( i.e  TA / TB  ) . Calculate to 2 decimals.