如何计算Enthalpy Change (Q=mcΔT)

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Enthalpy (H) is a thermodynamic property measuring the total heat content of a system at constant pressure. Enthalpy change ΔH = q = m × c × ΔT for calorimetry calculations. Exothermic reactions release heat (ΔH < 0); endothermic absorb heat (ΔH > 0).

分步指南

1. 1q = m × c × ΔT
2. 2m = mass in grams
3. 3c = specific heat capacity (water: 4.18 J/g·°C)
4. 4ΔT = final temperature − initial temperature
5. 5For combustion: q = −m_fuel × ΔHcombustion / molar mass

例题解析