Chapter 13 - Solutions and Their Physical Properties - Example 13-6 - Predicting Vapor Pressure of Ideal Solutions - Page 574: Practice Example A

$P_{hexane}=112\, mmHg$ $P_{pentane}=127\, mmHg$ $P_{total}=239\, mmHg$

Using Raoult's law, we have $P_{hexane}= x_{hexane}P^{\circ}_{hexane}$ $=0.750\times149.1\, mmHg=112\, mmHg$ $P_{pentane}=x_{pentane}P^{\circ}_{pentane}$ $=(1-0.750)\times 508.5\, mmHg$ $=127\, mmHg$ $P_{total}=P_{hexane}+P_{pentane}$ $=(112+127)\, mmHg=239\, mmHg$