Question

The total enthalpy of the products in a reaction is 0 kJ, and the total enthalpy of the reactants is 100 kJ. What is the ΔH for the reaction? Choose the correct answer.
a.–393.5 kJ
b.–100 kJ
c.0 kJ
d.+100 kJ

Answer 1

Answer: b. -100 kJ

Explanation:

Heat of reaction is the energy released or absorbed during the course of the reaction. It is represented by the symbol $\Delta H$.

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

$\Delta H$ = enthalpy of reaction = ?

$H_{products}$ = enthalpy of products = 0 kJ

$H_{reactants}$ = enthalpy of reactants = 100 kJ

$\Delta H=0kJ-100kJ$

$\Delta H=-100kJ$

Thus the ΔH for the reaction is -100kJ