Question

Which example is an exothermic reaction?

4Fe (s) + 302 (g) + 6H2O (l) → 4Fe(OH)3 (s) + heat
H2O (s) + heat → H₂O (1)
NH4NO3 + heat → NH++ NO 4
heat+C6H12O6 (s) + H2O (l) →→ C6H12O6 (l) + H₂O (1)

Answer 1

The example that represents an exothermic reaction is:

4Fe (s) + 3O2 (g) + 6H2O (l) → 4Fe(OH)3 (s) + heat

In this reaction, the formation of Fe(OH)3 releases heat.


The presence of "heat" on the product side of the equation indicates that energy is being released or given off during the reaction, which is a characteristic of exothermic reactions.

Answer 2

The example of an exothermic reaction is:

4Fe (s) + 3O2 (g) + 6H2O (l) → 4Fe(OH)3 (s) + heat

Step-by-step explanation:

The reaction provided, 4Fe (s) + 3O2 (g) + 6H2O (l) → 4Fe(OH)3 (s) + heat, is an example of an exothermic reaction because it releases heat as a product.

In exothermic reactions, the overall energy of the reactants is higher than the energy of the products. During the reaction, bonds between atoms are broken, and new bonds are formed to create the products. In this particular reaction, iron (Fe) reacts with oxygen (O2) and water (H2O) to form iron(III) hydroxide (Fe(OH)3).

The formation of the Fe(OH)3 solid releases heat, indicating that energy is being given off to the surroundings. The release of heat suggests that the products have a lower energy state than the reactants. Therefore, this reaction is classified as exothermic.

It's worth noting that the other provided reactions do not indicate the release of heat as a product, making them either endothermic or not directly associated with heat transfer.