# Lab-4 - EXP#4 EMF INTRODUCTION I-Objective-To obtain the temperature dependence of EMF and to calculate G S and H of the cell/reaction-To obtain Kc

This preview shows pages 1–3. Sign up to view the full content.

EXP#4 EMF INTRODUCTION I-Objective:- -To obtain the temperature dependence of EMF and to calculate G, S and H of the cell/reaction. -To obtain K c from EMF measurements. II-Theory:- Electrochemical measurements are the most accurate method for measuring thermodynamics properties like G, S and H of the reactions and activities of ionic solutes. Electrical Work = Charge Voltage X Joule = Coulomb Volt X For the system acting as a battery, this gives:- G nFE = - where, n = the number of moles of electrons that pass through the circuit per mole of reactants. F = 96485 C/mol e - . E = the voltage in volts. G depends upon the activities of the products and reactants:- G G RT Q = + o ln Where Q is the activity quotient. This gives the Nernst equation:- E E RT nF Q = o ln

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
where, E o o = - G nF By measuring the cell voltage at several different temperatures, the entropy change can be determined:- δ δ δ∆ δ E T nF G
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 04/13/2011 for the course CHEM 311 taught by Professor Alial-habib during the Fall '09 term at King Fahd University of Petroleum & Minerals.

### Page1 / 6

Lab-4 - EXP#4 EMF INTRODUCTION I-Objective-To obtain the temperature dependence of EMF and to calculate G S and H of the cell/reaction-To obtain Kc

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online