Question

PLZ HELP For the reaction: 2NO2(g) → N2O4(l),

Answer 1

Answer: $\Delta H_{rxn}=-20kJ/mol-(+66kJ/mol)$

Explanation:

Heat of reaction or enthalpy change is the energy released or absorbed during the course of the reaction.

It is calculated by subtracting the enthalpy of reactants from the enthalpy of products.

$\Delta H=H_{products}-H_{reactants}$

$\Delta H$ = enthalpy change = ?

$H_{products}$ = enthalpy of products

$H_{reactants}$ = enthalpy of reactants

For the given reaction :

$2NO_2(g)\rightarrow N_2O_4(l)$

$\Delta H=H_{N_2O_4}-2\times H_{NO_2}$

$\Delta H=-20kJ/mol-(+66kJ/mol)$