Question

A _____ (released, absorbed, taken, +,-) ΔH means that energy is______ (released, absorbed, taken, +,-) from a reaction.

Answer 1

A __"-"___  ΔH means that energy is_released_

Answer 2

Answer: The blanks are completed below.

Explanation:

Enthalpy change of the reaction is defined as the difference in the potential energy of the products and the potential energy of the reactants. It is represented as $\Delta H$

Mathematically,

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

When $\Delta H$ of the reaction is negative, then potential energy of the products is less than the potential energy of the reactants. So, energy is being released.

Thus, a +ve $\Delta H$ means that energy is released from a reaction.

When $\Delta H$ of the reaction is positive, then potential energy of the products is more than the potential energy of the reactants. So, energy is being absorbed.

Thus, a -ve $\Delta H$ means that energy is absorbed from a reaction.