Question

CHEM PLZ HELP Explain the energy changes that occur when the following reaction happens:

H2 + Cl2 → 2HCl
Select all that are correct.

Question 9 options:

Energy is absorbed when the HCl bonds form.


Energy is needed to break the bonds of H-H in H2 and Cl-Cl in Cl2


Energy is released when the bonds of H-H in H2 and Cl-Cl in Cl2 break.


Energy is released when the H-Cl bonds form.


No energy changes occur when this reaction happens.

Answer 1

Energy is needed to break the bonds of H-H in H2 and Cl-Cl in Cl2

Energy is released when the H-Cl bonds form.

Step-by-step explanation:

During a chemical reaction, energy is needed to break the bonds between reactants in order for reactants to recombine with each other to form products.

According to the collision theory, chemical reactions occur when reactant particles of appropriate activation energy collide with each other to form the products. This implies that energy must be absorbed in order to break Cl-Cl and H-H bonds in the reactants so that they can collide to form HCl. As the new bond is formed in the product, the excess energy absorbed by the reactants is given off.