standard entropy change using standard molar entropies

[mehaksk]

I am making my notes and would love to see how you would answer this in a structured way: How do you calculate the standard entropy change for a chemical reaction using the standard molar entropies of reactants and products, and what does this value indicate about the disorder or randomness associated with the reaction?

[William Baik DISC3B]

Given the standard molar entropies of reactants and products, you can calculate the standard entropy change using the equation: ΣS(products) - ΣS(reactants) = ΔS(system). If this value is negative, it indicates entropy decreases, meaning disorder decreases in the system; if it is positive, the opposite is true, wherein disorder increases.

[Kennady 2C]

You would take the sum of the standard molar entropies of the reactants and subtract this from the sum of the standard molar entropies of the products to calculate the change in standard entropy of the reaction. In other words standard entropy change = (sum of standard entropies of products) - (sum of standard entropies of reactants)