Answer:
(4) an electrolytic cell, because it is endothermic.
Explanation:
You can see that we're using electricity to carry out the reaction, so this reaction is occuring in an electrolytic cell.
Remember that electricity is a form of energy. In an exothermic process, the energy is released but in an endothermic process, the energy is being absorb, and the process would required energy.
As you can note, this reaction requires electricity, it required energy, so this would be an endothermic process.
The answer would be (4) an electrolytic cell, because it is endothermic.
