Combustion of Diborane:

Diborane (B2H6) is a highly reactive and flammable gas. It undergoes combustion when exposed to an oxidizing agent, typically oxygen. The combustion reaction of diborane can be represented by the following equation:

2B2H6 + 6O2 -> 4B2O3 + 6H2O

Exothermic Nature:

The combustion reaction of diborane is exothermic. This means that it releases energy in the form of heat and light. The energy released during the reaction is greater than the energy required to initiate the reaction.

Explanation:

1. Definition: Combustion is a chemical reaction that occurs when a substance reacts with oxygen, typically producing heat and light.

2. Energy Change: In an exothermic reaction, the products have lower potential energy than the reactants. This results in the release of energy, usually in the form of heat.

3. Reaction: In the combustion of diborane, the reactants are diborane (B2H6) and oxygen (O2), and the products are boron trioxide (B2O3) and water (H2O).

4. Energy Release: The combustion of diborane is exothermic because the products (boron trioxide and water) have lower potential energy than the reactants (diborane and oxygen). The formation of chemical bonds in the products releases energy, resulting in the production of heat and light.

5. Heat of Combustion: The heat released during the combustion of diborane can be measured as the heat of combustion. This value represents the energy released per mole of diborane combusted. The exothermic nature of the reaction is reflected in the negative value of the heat of combustion.

6. Applications: The exothermic nature of diborane combustion is utilized in various applications. For example, diborane is often used as a rocket propellant because of its high energy release upon combustion.

In conclusion, the complete combustion of diborane is exothermic, meaning it releases energy in the form of heat and light. This is due to the lower potential energy of the products compared to the reactants.