Lecture_05

Problem 536 5 non ideal solutions non ideal solutions

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: , and solve for the mole fraction of methane. We should verify that this indeed is a small number so that the assumption made regarding the partial pressure of benzene is valid. Problem 5.36. 5 Non-ideal solutions: Non-ideal solutions are those that deviate from Raoult’s law. Positive deviation from Raoult’s law: P > xAPA* + (1 – xA)PB*. Negative deviation from Raoult’s law: P < xAPA* + (1 – xA)PB*. In many solutions, both components show the same type of deviation (positive or negative) from Raoult’s law so that we have either PA > xAPA* and PB > xBPB* or PA < xAPA* and PB < xBPB*. However, there are exceptions to this behavior, as seen in Fig. 5.9 (ethanol). When dealing with non-ideal solutions, it is convenient to define activity of a component as P (5.75) a A = PA .  A Obviously, for an ideal solution, Raoult’s Law is obeyed and, therefore, a A = x A . However, for a non-ideal solution, the activity will not be equal to the mole fraction. In such cases, the activity can be related to the mol...
View Full Document

This document was uploaded on 02/28/2014 for the course CHEM 311 at LA Tech.

Ask a homework question - tutors are online