2. Thermodynamics

Solution Thermodynamics — Quiz

Test your understanding of solution thermodynamics with 5 practice questions.

Practice Questions

Question 1

The excess enthalpy ($H^E$) of a binary solution is defined as the difference between the actual enthalpy of the solution and the enthalpy of an ideal solution at the same conditions. If a solution exhibits a positive excess enthalpy ($H^E > 0$), what does this imply about the heat effects upon mixing the components?

Question 2

For a binary solution of components A and B, the partial molar volume of component A ($\bar{V}_A$) is defined as the change in the total volume of the solution with respect to the change in the number of moles of A, while keeping temperature, pressure, and the number of moles of B constant. If the partial molar volume of component A is significantly larger than its pure molar volume ($V_A^*$), what can be inferred about the interactions of A within the solution?

Question 3

The fugacity coefficient ($\phi_i$) for a component $i$ in a real gas mixture is defined as the ratio of its fugacity ($f_i$) to its partial pressure ($P_i$), i.e., $\phi_i = f_i / P_i$. For a real gas mixture at very high pressures, how does the fugacity coefficient typically behave?

Question 4

Consider a system where a semipermeable membrane separates a pure solvent from a solution containing a non-volatile solute. The osmotic pressure ($\Pi$) is the pressure that must be applied to the solution to prevent the net flow of solvent across the membrane. If the concentration of the solute in the solution is doubled, how does the osmotic pressure change, assuming ideal dilute solution behavior?

Question 5

The Gibbs-Duhem equation is a fundamental thermodynamic relationship that connects the changes in chemical potentials of components in a mixture. For a binary solution at constant temperature and pressure, the Gibbs-Duhem equation can be expressed as $x_1 d\mu_1 + x_2 d\mu_2 = 0$. What is the most significant implication of this equation for understanding solution behavior?