For the homogenous reaction,

${\text{4NH}}_{\text{3}}\text{(g)}\text{+}{\text{5O}}_{\text{2}}\text{(g)}\rightleftharpoons \text{4NO(g)}\text{+}{\text{6H}}_{\text{2}}\text{O(g)}$

the equilibrium constant ${\text{K}}_{\text{c}}$ has the units

• A

  $\mathrm{c}\mathrm{o}\mathrm{n}\mathrm{c}{.}^{+10}$
• Correct answer
  B

  $\mathrm{c}\mathrm{o}\mathrm{n}\mathrm{c}{.}^{+1}$
• C

  $\mathrm{c}\mathrm{o}\mathrm{n}\mathrm{c}{.}^{-1}$
• D

  It is dimensionless

Hence, the correct answer is option: 'B'.