[HelpME]

hey guys,

i am having a lil trouble with 2 of my homework problems. they deal with enthlapy and entropy.

my first question is below.
(this is are the reactions)
Rxn (1): 2 H2(g) + O2(g)  2 H2O(l)
Rxn (2): C(s, graphite) + 2 H2(g)  CH4(g)
Rxn (3): C2H5OH(l) + 3 O2(g)  2 CO2(g) + 3 H2O(l)
Rxn (4): Fe2O3(s) + 2 Al(s)  Al2O3(s) + 2 Fe(s)


a) What is ΔGo for Rxn (1)? i got the answer as - 474.2
when i solve for the second part is where i get stuck.
   
What is ΔG at 298 K if P = 0.25 bar for each gaseous substance in Rxn (1)?
i keep getting large numbers.

for delta H i got this : (2)(285.83)-(0)+(2)(0)= 571.66
for delta S i got this : (2)(69.95)-(250.152)+(2)(130.62)= -371.4
i solve for delta G doing the following: G= H-TS.

my answers are really big and they are wrong.