Raoult's law: Difference between revisions
m (Slight tidy.) |
Jfcastillo (talk | contribs) No edit summary |
||
| Line 1: | Line 1: | ||
'''Raoult's law''' states that the [[vapour pressure]] of an [[ideal solution]] of | '''Raoult's law''' states that the [[vapour pressure]] of an [[ideal solution]] of N components is: | ||
:<math>P_v = | :<math>P_v = \sum_{i=1}^{N} X_i P^*_{v,i} </math> | ||
where <math>X_i</math> is the [[molar fraction]] of component <math>i</math>, and <math>P^*_{v,i}</math> is the vapour pressure of pure <math>i</math>. | where <math>X_i</math> is the [[molar fraction]] of component <math>i</math>, and <math>P^*_{v,i}</math> is the vapour pressure of pure <math>i</math>. | ||
More generally, Raoult's law describes the [[partial pressure]] of component <math>A</math> in the vapour coexisting with a liquid mixture as: | More generally, Raoult's law describes the [[partial pressure]] of component <math>A</math> in the vapour coexisting with a liquid mixture as: | ||
Revision as of 12:34, 19 February 2009
Raoult's law states that the vapour pressure of an ideal solution of N components is:
where is the molar fraction of component Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle i} , and Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle P^*_{v,i}} is the vapour pressure of pure Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle i} . More generally, Raoult's law describes the partial pressure of component Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle A} in the vapour coexisting with a liquid mixture as:
- Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle P_A = X_A P^*_{v,A} } .
This law is obeyed for all components of an ideal solution, and is also obeyed for the solvent of an ideal dilute solution. The solute's partial pressure of such solutions then obey Henry's law. Ideal dilute solutions describe the limiting behaviour of a mixture of infinite dilution. Therefore, all solutions in the limit of infinite dilution obey Raoult's law, i.e.:
- Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \lim_{X_A \rightarrow 1} P_A = X_A P^*_{v,A} } .