91影视

The energy held in the bonds of chemical compounds is known as chemical energy (molecules and atoms). It is produced as a by-product of the chemical reaction, which is known as an exothermic reaction.

In the event of atmospheric ${\mathrm{N}}_2$fixation, energy is acquired through natural lightning. The endothermic reaction between ${\mathrm{N}}_2$and ${\mathrm{O}}_2$gases in the atmosphere produces nitric oxide $\mathrm{NO}$causing the N-N bond to be broken after gaining $180.60\mathrm{kJ}$of energy. Later, the $\mathrm{NO}$is changed to ${\mathrm{NO}}_2$and ${\mathrm{HNO}}_3$resulting in nitrate ion penetration into the soil and sea. In the Haber ammonia production process, the N鈥揘 bond is broken under high reaction conditions of $450掳\mathrm{C}$and $200\mathrm{atm}$pressure.

Therefore, atmospheric fixation by lightning and industrial fixation by high temperature-pressure circumstances.

The enthalpy of$\mathrm{NO}$production while breaking the N鈥揘 bond is$180.6\mathrm{kJ}/\mathrm{mol}$

for atmospheric fixing. As a result, the reaction is endothermic, and energy (heat) is drawn from the environment.

The Haber鈥檚 process within the industrial fixation process, as seen in Chapter 17, has an enthalpy of

$-91.8\mathrm{kJ}/\mathrm{mol}$. As a result, the reaction is highly exothermic, with heat being emitted into the environment.

In the case of biological fixation, the root bacteria catalyse a multistep mechanism to decrease ${\mathrm{N}}_2$to ammonia. As a result of the use of a catalyst (in this case, an enzyme), the reaction's activation energy鈥攖hat is, the minimum energy necessary to break the N鈥揘 bond鈥攊s reduced. As a result of the root bacteria's enzymes lowering the necessary energy barrier, biological ${\mathrm{N}}_2$ fixation happens at considerably gentler temperatures.

If the activation energy of ${\mathrm{N}}_2$fixation was reduced, more nitrogen gas molecules would be broken apart. As a result, more N-containing compounds would be created, and N levels in the soil and sea would rise.

Excess nitrogen in the water, which acts as a fertiliser, can lead to eutrophication, in which more nutrients build in the water and soil. This would result in an excessive development of algae, which would cover the water's surface. As a result, there will be less oxygen available, fish will die, and the ecology will be ruined.