Question

For decomposition of ${\mathbf{N}}{{\mathbf{H}}_{\mathbf{3}}}\left( {\mathbf{g}} \right)$ in a sealed tube:
A. ${K_P}$ does not change with pressure
B. Concentration of ${H_2}$ (g) is less than of Nitrogen
C. Concentration of ammonia does not change with pressure
D. None of the above

Answer 1

In the given question the reaction of decomposition occurs in a sealed tube. So, we have to discuss the reaction of ammonia, in the essence of pressure and concentration of hydrogen and nitrogen gas, by using the following method at constant pressure.

Complete step by step solution:
The Kjeldahl method or we can say Kjeldahl digestion is defined in analytical chemistry as it is a method for the quantitative determination of nitrogen contained in any of the organic substances along with the nitrogen contained in the inorganic compounds such as ammonia.
According to the given question:
A constant temperature is the equilibrium constant that is denoted by ${K_p}$ for the decomposition reaction ​ is expressed by ${K_p}$.${K_{P}} = \dfrac{{\left( {4{x^2}p} \right)}}{{\left( {1 - {x^2}} \right)}}$ , where $p$ = pressure and $x$ = extent of decomposition and ${K_p}$​ remains constant with change in values of $p$ and $x$.The value of the equilibrium constant is self-regulating and independent of the partial pressure or from degree of dissociation.
The ${K_p}$​ is a constant for a specific reaction at a particular temperature. Therefore, it will not change along with pressure so we can say that the ${K_p}$​ only changes, if temperature is changed.

Hence, option A is correct.

Note: The Kjeldahl method was developed by Johan Kjeldahl, that’s why it is named after him. In this method heating of a sample at a temperature of $360-410^\circ C$ along with concentrated sulfuric acid which will further decomposes or in other words digests the organic sample by the oxidation reaction which liberate the reduced nitrogen in form of ammonium sulfate.