Calculate S (measure of total entropy) for the following reaction at 25C and 1atm, and tell whether the entropy is increasing or decreasing.

C3H8(g)+5O2(g)-> 3CO2(g)+4H2O(g)
S of C3H8=64.5 cal/(mol*K)
S of O2= 49 cal/(mol*K)
S of CO2= 51.1 cal/(mol*K)
S of H2O= 45.1 cal/(mol*K)

S of the equation is 23.9 and increasing entropy.

I do not know how to factor in the temp. and atm... please help!!!

1 answer

Is this just
Srxn = Sproducts-Sreactants.
And if you look them in a table, that is at 25 C and 1 atm isn't it.