Question

Two separate chambers containing equilibrium mixtures of H2, N2, NH3 and D2, N2, ND3 are connected with each other, after some time the mixture will contain

Answer 1

N2(g)+3H2(g)⇌2NH3(g)

At eqm    0.036M   0.15M   x

KC=[N2]×[H2]3[NH3]2⇒0.29=0.036×(0.15)3x2

⇒x=5.9×10−3M

∴ Concentration of NH3 is 5.9×10−3M .

Answer 2

Two separate chambers containing equilibrium mixtures of $H2, N2, NH3 and D2, N2, ND3$ are connected with each other, after some time the mixture will contain no mixing of isotopes.

Explanation:

• Separate chambers contain equilibrium mixtures  $H2, N2, NH3 and D2, N2, ND3$  with each other.

• Both the chambers are connected.

• The reaction mixtures starts with either with$H2$ or $D2$ reach equilibrium with the same composition, except that $D2$ and $ND3$ are present instead of $H2$ and $NH3$.
• After equilibrium is attained, these two mixtures $(H2, N2, NH3 and D2, N2, ND3)$) are mixed together and left for a while.
• After some time when this mixture is checked and analyzed, it was found that the concentration of ammonia is just the same as before.
• Later when this mixture was analyzed with the help of a mass spectrometer, it was found that ammonia and all deuterium contain forms of ammonia (NH3, NH2D, NHD2, and ND3), and dihydrogen and its deuterated forms(H2, HD, and D2) were present.
• In this way, it can be concluded that scrambling of H and D atoms in the molecules results in a continuation of the forward and reverse reactions in the mixture.
• If the reaction had simply stopped when they reached equilibrium, then there would have been no mixing of isotopes in this way.