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!!!

To calculate the change in entropy (ΔS) for a reaction, you can use the following equation:

ΔS = ΣnS(products) - ΣmS(reactants)

where ΣnS(products) represents the sum of the product entropies multiplied by their stoichiometric coefficients, and ΣmS(reactants) represents the sum of the reactant entropies multiplied by their stoichiometric coefficients.

In this case, the reaction is as follows:

C3H8(g) + 5O2(g) -> 3CO2(g) + 4H2O(g)

Given the entropies of the involved substances:

S(C3H8) = 64.5 cal/(mol*K)
S(O2) = 49 cal/(mol*K)
S(CO2) = 51.1 cal/(mol*K)
S(H2O) = 45.1 cal/(mol*K)

We can calculate the change in entropy as follows:

ΔS = (3 * S(CO2) + 4 * S(H2O)) - (S(C3H8) + 5 * S(O2))
= (3 * 51.1 cal/(mol*K) + 4 * 45.1 cal/(mol*K)) - (64.5 cal/(mol*K) + 5 * 49 cal/(mol*K))
= 153.3 cal/(mol*K) + 180.4 cal/(mol*K) - 64.5 cal/(mol*K) - 245 cal/(mol*K)
= 23.2 cal/(mol*K)

The change in entropy (ΔS) for this reaction is 23.2 cal/(mol*K). Since ΔS is positive, it indicates that the entropy is increasing.