Use the data in Appendix B in the textbook to calculate H and S for each of the
ID: 973779 • Letter: U
Question
Use the data in Appendix B in the textbook to calculate H and S for each of the following reactions. From the values of H and S, calculate G at 25 C and predict whether each reaction is spontaneous under standard-state conditions.
Part A
2SO2(g)+O2(g)2SO3(g)
Express your answer using four significant figures.
H =
kJ
Part B
Express your answer using four significant figures.
S =
J/K
Part C
Express your answer using four significant figures.
G =
kJ
Part D
spontaneous under standard-state conditions
nonspontaneous under standard-state conditions
Explanation / Answer
enthalpy change of SO2= -296.8 Kj/mol
enthalpy change of SO3= -395.6 Kj/Mol
Enthalpy change for O2=0
Enthalpy change at standard conditions= sumof Enthalpy change of products- sum of Enthalpy change of reactants
2* enthalpy change of SO3-{ 2* enthalpy change of SO2+1* enthalpy change of Oxygen)
2,2 and 1 are stoichiometric coefficients of SO3,SO2 and O2 respectively.
=2*(-395.6)- {2*(-296.8)}=-197.6 Kj
b) entropy change data : SO3 : 256.6 J/mol.K, SO2 : 248.1 J/mol.K and O2=205.3 J/mol.K
Similar to the way entropy change is calculated by =sume of entropy changes of products- sum of entropy changes of reactants
entropy change= 2*256.6-{2*248.1+205.3)=-188.3 J/K
3. delG= delH- TdelS = -395.6-(298.15*(-188.3/1000) =-395.6 +298.15*188.3/1000=-339.458 Kj
since delG is -ve, the reaction is spontaneous at 25 deg.c
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.