Heat released or absorbed by chemical reaction in constant volume reaction (the temperature of initial state and final state is the same as that of heat source) Qv=∑ U (product) - ∑ U (reactant)=△ U. Constant volume reaction heat (Q p ）The relationship with isobaric reaction heat (Qv) can be approximately expressed as follows: Q p =Q v +p(V two -V one )=Qv+△nRT。 Where V two And V one They respectively represent the total volume of products and reactants in the isobaric process, and △ n represents the change of the amount of substances existing in the gaseous state before and after the reaction. R is the gas constant. [1]
