Question

The standard enthalpy of formation of ${\mathrm{NH}}_3$ is

Answer 1

Enthalpy:

• It is a thermodynamic measure that represents the system's overall heat content.
• It is equivalent to the sum of the system's internal energy and the volume and pressure product.

Formation of Ammonia:

• Ammonia $\left({\mathrm{NH}}_3\right)$ is formed as a product of the reaction between Nitrogen $\left({\mathrm{N}}_2\right)$ and Hydrogen $\left({\mathrm{H}}_2\right)$ gas.

$\underset{\mathrm{Nitrogen}}{\underbrace{\frac{1}{2}{\mathrm{N}}_2}}\left(\mathrm{g}\right)+\underset{\mathrm{Hydrogen}}{\underbrace{\frac{3}{2}{\mathrm{H}}_2}}\left(\mathrm{g}\right)\to \underset{\mathrm{Ammonia}}{\underbrace{{\mathrm{NH}}_3}}\left(\mathrm{g}\right)$

• The structure of Ammonia is as shown in the figure,

Figure: Structure of Ammonia

• This reaction of Ammonia synthesis is Exothermic in nature which implies that heat is released when the reaction takes place.
• The standard Enthalpy of formation of Ammonia is $46kJ/mol$.