Which of the following correctly depicts the attainment of equilibrium for the reaction:
`N_2(g)+3H_2(g)hArr2NH_3(g)`
beginning with stoichiometric amounts of `N_2(g)` and `H_2(g)` and no `NH_3(g)`.

Options

A.
B.
C.
D.

Answer

B

Explanation

In the beginning (when time is zero), the concentrations of `N_2` and `H_2` are maximum and the concentration of `NH_3` is zero (because no `NH_3` is present in the container). When `N_2` and `H_2` react, their concentrations decrease with time while the concentration of `NH_3` increase due to its formation. When equilibrium is attained, there is no net reaction. Thus, the concentrations of `N_2`, `H_2`, and `NH_3` become constant.