1. Tardigrade
  2. Question
  3. Chemistry
  4. Ammonia undergoes self-dissociation according to the reaction, 2 NH 3(l) leftharpoons NH 4+ (a m)++ NH 2(a m)- where am, stands for ammoniated. When 1 mole of NH 4 Cl is dissolved in 1 kg of liquid ammonia, the b. p. at 760 tour is observed at -32° C (Normal b.p. of N H3(l) is -33.4° C ). What conclusions are reached about the nature of the solution?

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. Ammonia undergoes self-dissociation according to the reaction,
$2 NH _{3}(l) \rightleftharpoons NH _{4}^{+}{ }_{(a m)}^{+}+ NH _{2(a m)}^{-}$
where am, stands for ammoniated. When $1$ mole of $NH _{4} Cl$ is dissolved in $1\, kg$ of liquid ammonia, the b. p. at $760$ tour is observed at $-32^{\circ} C$ (Normal b.p. of $N H_{3(l)}$ is $-33.4^{\circ} C$ ). What conclusions are reached about the nature of the solution?

AMUAMU 2012Equilibrium

Solution:

Vapour pressurs, $\pi \propto b p(T)$
$\therefore \frac{\pi_{1}}{\pi_{2}}=\frac{T_{1}}{T_{2}}$
$\Rightarrow \frac{760}{\pi_{2}}=\frac{240.3\, K }{306.4\, K }$
$\pi_{2}=\frac{760 \times 306.4}{240.3}=969$ torr
$\because \pi_{2}>\pi_{1}$ that means more gases are present
or $NH _{4} Cl$ gets completely dissociated into ammonia gas.