Law Of Chemical Equilibrium And Equilibrium Constant

We are given: Initial pressure, , Final pressure, , Initial temperature = 27°C = 300 K,
Final temperature = 347°C = 620 K.
We can use the concept of partial dissociation to solve this problem. The balanced dissociation equation is: Let the initial moles of NH be . Let the extent of dissociation be , so: The number of moles of NH remaining = , The number of moles of N formed = , The number of moles of H formed = . The total number of moles after dissociation is: Using the ideal gas law for the initial and final states: Since the volume and gas constant are constant, the equation simplifies to: Substituting into the equation: Now, we substitute the known values: Cross-multiply: Thus, the percentage dissociation is: Therefore, the correct percentage dissociation of NH is 38.7%, corresponding to (B).