The thermite reaction, Fe2O3 + Al S Al2O3 + Fe produces so much heat that the Fe product melts. This reaction is used industrially to weld metal parts under water, where a torch cannot be employed. It is also a favorite chemical demonstration in the lecture hall (on a small scale). (d) If you performed the reverse reaction— aluminum oxide plus iron makes iron oxide plus aluminum—would that reaction have heat as a reactant or a product?

Video transcript

Hello everyone. So first I'm going to go ahead and informally translate all these words in the problem into a chemical reaction. I say informally because I'm not going to go ahead and write the proper chemical reaction. I just want to roughly translate this to see what exactly is going on in a chemical in a chemistry point of view. And so we can see here. So let's first state that we're going to go ahead and write out the forward reaction, saying that the potassium reacts intensely with water to form potassium hydroxide and highly flammable hydrogen. So it says that the reaction can cause a small explosion due to heat released, igniting the hydrogen. So it's saying that the heat is released, meaning that heat is going to be one of our by products. So we have heat as well. And it's asking in this problem if that the reverse reaction is going to have the heat being the starting material or our product. And so our reverse reaction, basically what we're doing here is not now the products is going to be our starting materials and our star materials are going to be our products. So we just kind of flipping it around. So we have the K. O. H. Are highly flammable hydrogen and we have the heat byproduct as now are starting materials and our new products is going to be the potassium and the water. So, as you can see from this chemistry, right chemical occasion right here is that now we have the heat being a reactant and not a product. So, to properly answer this question. So my answer is that heat is a reactant and the reverse reaction, and that is going to be my final answer for this problem. Thank you all so much for watching.