CH 302 - Learning Module 1: Vapor Pressure

Match the following quantities with their corresponding descriptions.

40 kJ/mol = water's enthalpy of vaporization 8.3 kJ/mol = ideal gas constant 25 mmHg = water's vapor pressure at room temperature 760 mmHg = vapor pressure at which water boils 0.7 = natural log of 2

Rank the following from highest boiling point to lowest boing point: NH3, NaCl, CH4, CH3Cl

NaCl, NH3, CH3Cl, CH4

Which of the following statements is false? - When a system reaches equilibrium, ΔH=0 - Change in Gibbs free energy, ΔG, is defined as ΔG=ΔH−TΔS - The change in entropy, ΔS, when two things are mixed is generally positive. - A chemical will have a greater standard entropy, S°m, in the gas phase than the liquid phase

When a system reaches equilibrium, ΔH=0

As the temperature of a liquid increases, its vapor pressure

increases exponentially

Given the data in the table above, which of the substances most likely exhibits H-bonding?

y

The images above depict two systems with different vapor pressures. Select all of the true statements below.

- If both systems are at the same temperature, then they must have different chemical compositions. - If both systems have the same chemical compositions, then the System 2 must have a higher temperature.

When deriving the equation P=Ke^(ΔHvap/RT) which of the following assumptions are made?

- We assume that the standard molar entropy of all gases is a constant. - We assume the free energy of a liquid does not depend on pressure.

The two flasks above contain different amounts of the same pure liquid at the same temperature. The vapor pressure in the left flask will be ____________ the vapor pressure in the right flask because ____________________________.

- the same as - they are at the same temperature