The reaction enthalpy If the trans fer of heat occurs at constant volume and if no other forms of work are permitted (△Uy=Q For a specified change of state AU is independent of how the change is brought about, therefore the subscript v can be dropped from U: AU=Qv The significance of this equation is that if we measure the heat transferred at constant volume we can identify it with the change in a thermodynamic state function 4上一内容下一内容令回主目录 返回 2021/223上一内容 下一内容 回主目录 返回 2021/2/23 If the transfer of heat occurs at constant volume, and if no other forms of work are permitted, (△U)v = Qv . For a specified change of state △U is independent of how the change is brought about,therefore the subscript v can be dropped from U: △U = Qv . The significance of this equation is that if we measure the heat transferred at constant volume we can identify it with the change in a thermodynamic state function. The reaction enthalpy