Answer to Question #63425 in General Chemistry for S

Question

Chapter 15 (15.98)

In Section 11.5 in the textbook we defined the vapor pressure of a liquid in terms of an equilibrium.

1) Write the equation representing the equilibrium between liquid water and water vapor.

2) Write the corresponding expression for Kp.

3) By using data in Appendix B in the textbook, give the value of Kp for this reaction at 30 ∘C.

4) What is the value of Kp for any liquid in equilibrium with its vapor at the normal boiling point of the liquid?

Answer 1

1) H2O(l) = H2O(g), 43.990 kJ/mol

2) Kp = [H2O(g)]/[H2O(l)]

3) Kp = 31.8 torr/760 torr (30 C)

4) Kp = Kc∙(RT)^(Δng)