Question

For the homogeneous reaction,
$ 4N{{H}_{3}}+5{{O}_{2}} \rightleftharpoons 4NO+6{{H}_{2}}O $
the equilibrium constant $ {{K}_{c}} $ has the units

• A. $ conc{{.}^{+10}} $
• B. $ conc{{.}^{+1}} $
• C. $ conc{{.}^{-1}} $
• D. It is dimensionless

Answer 1

Answer: (B)

For the given reaction, $ \Delta {{n}_{g}}={{n}_{p}}-{{n}_{r}} $
(where, $ {{n}_{p}}= $ number of moles of gaseous products and
$ {{n}_{r}}= $ number of moles of gaseous reactants.)
$ \Delta {{n}_{g}}=(6+4)-(4+5)=+1 $
Units of $ {{K}_{c}}={{(concentration)}^{\Delta {{n}_{g}}}} $$ ={{(concentration)}^{+1}} $