Question

This assignment is designed to give practice at determining the thermodynamic data for a reaction that is of some industrial importance. For the compound assigned, go to the library and find out how the compound is prepared industrially. Some compounds are prepared by a number of methods. Choose only one method to discuss. The narrative should not be long (half a page maximum). Include special apparatus, and write a balanced equation for the reaction. The processes assigned can usually be written as a single overall reaction.

Once you have the equation, determine the ΔH0, ΔS0, and ΔG0 for the reaction at 298 K using the data from the back of the text or other sources such as the Handbook of Chemistry and Physics if needed. Also determine the

ΔG at the temperature used in the industrial process if different from 298 K.
Finally, use Le Chateliers principle to explain how the industrial process can maximize the yield of the

product.

Compound Assigned:

-Hydrochloric acid by the Leblanc process
2 NaCl (s) + H2SO4 (aq)àNa2SO4 (s) + 2 HCl (g

Answer 1

2. for the reaction 2NaCl+ H2SO4-----à Na2SO4 + 2HCl

Enthalpy change = sum of enthalpy of products- sum of enthalpy of reactants.

Enthalpy data ( Kj/mole) : NaCl = -411.15, H2SO4 = -813.99, Na2SO4= -1387         HCl =-92.31

Enthalpy change = -1387+2*(-92.31) – { 2*(-411.15) + (-813.99)}=64.67 Kj/mole

Entropy data ( J/mole.K) NaCl =72.4, H2SO4= 156.9, Na2SO4= 149.8 , HCl(g)=186.6

Standard entropy change= 149.8+2*186.6 –(2*72.4+156.9)=184.5 j/K

1,2, 2 and 1 are coefficients of products and reactants.

Gibbs free energy change = deltaH- T delta S= 64.67*1000-184.5*298=9689 J=9.689 KJ