Question

ChemActivity T10 Gibbs En Gibbs Energy as a Function of Temperature and Pressure 123 Provide an expression for Hz(pure) in terms of it, temperature, and pressure. 10. Provide an expression for PH2 (mix) and then generalize this expression for any gas in an ideal mixture. Exercise Pd membrane H2 (mix) H2 (pure) T= const N2 (mix) a) What is the relationship of ph(pure) to when PH2(pure) = 1 bar? b) If PH (mix)=0.5 bar and PH2(pure) = 1 bar, on which side of the membrane is the free energy of hydrogen the lowest? In which direction will there be a gas flow? If PH2(mix) = 1 bar and PH2(pure) = 0.5 bar, on which side of the membrane is the free energy of hydrogen the lowest? In which direction will there be a flow of gas?

Answer 1

Solution :

9) Chemical potential ($\mu$) is related with temperature (T) and pressure (P) as,

$\mu$ = $\mu$ ° + RT ln P

Where,

$\mu$°= chemical potential for pure substance

Thus, for H2 molecule,

$\mu$(H2) = $\mu$ °(H2) + RT ln P

10) Chemical potential for an ideal gas mixture,

$\mu$i = $\mu$ i ° + RT ln Pi /P°

Where, Pi = pressure of ith component

P°= standard pressure