反应热计算器 — 公式
## Hess's Law
### Principle
**ΔH_total = ΔH₁ + ΔH₂ + ΔH₃ + ...**
Enthalpy is a state function, so the total enthalpy change depends only on the initial and final states, not the pathway. You can add up enthalpy changes of intermediate steps to find the overall change.
Reverse a reaction: change sign of ΔH. Multiply coefficients: multiply ΔH by the same factor.
### Principle
**ΔH_total = ΔH₁ + ΔH₂ + ΔH₃ + ...**
Enthalpy is a state function, so the total enthalpy change depends only on the initial and final states, not the pathway. You can add up enthalpy changes of intermediate steps to find the overall change.
Reverse a reaction: change sign of ΔH. Multiply coefficients: multiply ΔH by the same factor.
计算示例
Three-step pathway: Step 1 = -200 kJ, Step 2 = -150 kJ, Step 3 = +50 kJ.
- ΔH_total = ΔH₁ + ΔH₂ + ΔH₃
- ΔH_total = -200 + (-150) + 50
- ΔH_total = -300 kJ