Why exactly is this exothermic

[LSJ]

Bah, template doesn't apply to this.

In a lab report, we were using Hess's Law to calculate enthalpies using a few reactions we did in class, one of which was magnesium in hydrochloric acid. The question was to explain why the change is exothermic.

What exactly is it about displacement reactions of metals in acids that makes them exothermic?



In this case,

Mg + 2HCl --> MgCl2 + H2 + xkJ

 

[ace123]

well heat is produced so...

 

[Blueshift5]

/mol

The reaction between magnesium and hydrochloric acid is exothermic because it releases energy in the form of heat. This is due to the formation of new chemical bonds between magnesium and chlorine, as well as the release of hydrogen gas. When magnesium atoms react with hydrochloric acid, the outer electrons of the magnesium are transferred to the chlorine atoms, forming magnesium chloride. This process releases energy, which is then further increased by the formation of hydrogen gas. The overall result is a decrease in the potential energy of the system, resulting in an exothermic reaction. Additionally, the formation of ionic bonds in the product (magnesium chloride) is more stable than the covalent bonds in the reactants (magnesium and hydrochloric acid), leading to a release of energy. This is why displacement reactions of metals in acids are typically exothermic.