An enthalpy change describes the change in enthalpy observed in the constituents of a thermodynamic system when undergoing a transformation or chemical reaction.

中文名 焓 外文名 enthalpy [1] 别 名 热焓、热容量、热函数等 表达式 H=U+pV 适用领域 热力学 应用学科 工程热力学、化学 单 位 J（焦耳） 符 号 H

Nov 18, 2025 · Enthalpy is an energy-like property or state function—it has the dimensions of energy (and is thus measured in units of joules or ergs), and its value is determined entirely by …

When a process occurs at constant pressure, the heat evolved (either released or absorbed) is equal to the change in enthalpy. Enthalpy (H) is the sum of the internal energy (U) and the …

焓（Enthalpy）是表征物质系统能量的一个重要状态参量，等于内能与压强和体积的乘积之和，通常表示为H。 定义公式如下： H=U+P*V

Enthalpy is a state function of a thermodynamic system and depends on other state functions. Mathematically, it is the sum of the internal energy and the product of the pressure and volume …

Learn how chemists use enthalpy change (ΔH) to quantify the heat released or absorbed in chemical reactions. Explore thermochemical equations and enthalpy level diagrams.

焓 hán （英語： Enthalpy）是一个 热力学 系统中的 能量 参数。 规定由字母 表示（ 来自于英语 （热容）一词），单位為 焦耳 （ ）。

焓是物体的一个热力学能状态函数，即热函：一个系统中的热力作用，等于该系统内能加上其体积与外界作用于该系统的压强的乘积的总和 (Enthalpy is a combination of internal energy and …

Chemists ordinarily use a property known as enthalpy (H) to describe the thermodynamics of chemical and physical processes. Enthalpy is defined as the sum of a system’s internal energy …