Reaction Entropy Calculator
🔥 Thermochemistry & Bonding. Use the Reaction entropy formula to find δs°rxn, σ s° products, σ s° reactants: pick the value you want, type the others, and the answer updates as you go.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| ΔS°rxn | J/(mol·K) |
| Σ S° products | J/(mol·K) |
| Σ S° reactants | J/(mol·K) |
Worked example
Find the δs°rxn when Σ S° products = 353 J/(mol·K), Σ S° reactants = 596 J/(mol·K).
Using Δ S°rxn = Σ S°(prod) - Σ S°(react): ΔS°rxn = -243 J/(mol·K).
Frequently asked questions
What is the formula for Reaction entropy?
Δ S°rxn = Σ S°(prod) - Σ S°(react).
What do the letters stand for, and what units are used?
ΔS°rxn in J/(mol·K), Σ S° products in J/(mol·K), Σ S° reactants in J/(mol·K).
How do you calculate δs°rxn?
Put the values into Δ S°rxn = Σ S°(prod) - Σ S°(react). For example, with Σ S° products = 353 J/(mol·K), Σ S° reactants = 596 J/(mol·K), δs°rxn = -243 J/(mol·K).
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (δs°rxn, σ s° products, σ s° reactants) and fill in the others: it rearranges the formula for you.
