Vapor Liquid Equilibrium Lab TAs Faculty instructor Prof. - - PowerPoint PPT Presentation

TH-206 Vapor Liquid Equilibrium

Faculty instructor Lab TA’s

• Prof. H.S.Shankar

Mriganka Mondal Yogendra singh M Bhavishya Staff member:

• Mrs. Annie

Objective of the Experiment

 To generate vapor liquid equilibrium data for

acetone-benzene binary system.

I.

Check thermodynamic consistency of the experimental data.

II.

Present the thermodynamic characteristics and calculate constants of Van Laar equation and Margules equation.

Measurement of concentration

 Concentration of the sample mixture is calculated

by measuring refractive index using analog Refractometer.

 Refractive index is nothing but ratio of velocity of

light in vacuum to a certain medium.

Experimental set up

Vapor sample collector Liquid sample collector RTD for temp measurement

Steps involved during experiment

• Get calibration curve for RI Vs Concentration.
• Initially mixture - 420ml Acetone + 80ml Benzene.

Measure its RI.

• Run the expt. till the equilibrium reaches.
• Take liquid and vapor samples for RI calculation.
• Take some amount of mixture out and add same

amount of Benzene to the mixture.

• Repeat this.

Calculations

• Modified Rault’s law
• Calculation of Van Laar equations
• Plot ln γA, ln γB (on the same graph) and ln(γA / γB) vs XA (as another

graph) and check for thermodynamic consistency.

• Calculate back the van Laar coefficients using

Problems and precautions

 The improper measurement of temperature by RTD

sometimes effects the calibration.

 Low efficiency of the dimmerstat (heating element).  Non uniform heating leads to sudden build up of

pressure inside the container.

 Glasses must be used during the experiment as a

necessary precaution.

Thank you