Which of the following elements will function as an cathode when it reacts with Mg? 1. Ba
2. Ag
3. Sr
4. K

2. Ag

Explanation:

A cathode gains electrons therefore electrons are reduced. Silver (Ag) is a stronger oxidising agent than magnesium.

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.