反应商计算器
计算化学反应的反应商Q，判断反应方向。
Heat of Reaction per Mole
-500.0 kJ/mol
Heat of Reaction per Mole vs Total Heat Measured (q)
公式
## Heat of Reaction per Mole ### Formula **ΔH_rxn = q / n** Where: - **ΔH_rxn** = heat of reaction per mole (kJ/mol) - **q** = total heat measured (kJ), negative for exothermic - **n** = moles of limiting reagent This converts calorimetry data into a molar enthalpy value for the reaction.
计算示例
A reaction releases 50 kJ of heat using 0.1 mol of limiting reagent.
- 01ΔH_rxn = q / n
- 02ΔH_rxn = -50 / 0.1
- 03ΔH_rxn = -500 kJ/mol
常见问题
What is heat of reaction?
Heat of reaction is the enthalpy change per mole of reaction as written. It depends on the balanced equation and the stoichiometric coefficients used.
How do I determine the sign of q?
If the temperature of the surroundings increases, the reaction is exothermic and q is negative. If the temperature decreases, q is positive (endothermic).
Is heat of reaction the same as enthalpy of reaction?
At constant pressure, yes. The heat measured at constant pressure equals ΔH. At constant volume (bomb calorimeter), q equals ΔU, not ΔH.
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