Question

Given the values of DeltaH degree_rxn, DeltaS degree_rxn, and T below, determine DeltaS_univ.

Answer 1

Solution:

Part A : Delta H⁰rxn = 88 kJ

Delta Srxn = 155 J / K,

T = 307 K

We have to calculated delta S of universe:

Delta H of universe = delta S of system + delta S of surrounding.

Delta of surrounding = - delta H / T

= - 88000 J / 307 K

= -286.645 J/K

Lets plug this value in above equation.

Delta S universe = [155 J + (-286.645) ] J/K

=-131.65 J/K

Part B :

Here we use same equation only T is changed.

Delta of surrounding = - delta H / T

= - 88000 J / 758 K

=- 116.095 J / K

Lets plug this value

Delta S universe = 155 + (-116.094) J / K = 38.905 J/K