Question

Predict the shift in equilibrium that will occur for each of the following processes when the volume is decreased.
$1.P_4\left(s\right)+6C{l}_2\left(g\right)\rightleftharpoons 4PC{l}_3\left(g\right)$
$2.PC{l}_3\left(g\right)+C{l}_2\left(g\right)\rightleftharpoons PC{l}_5\left(g\right)$
$3.PC{l}_3\left(g\right)+3N{H}_3\left(g\right)\rightleftharpoons P\left(N{H}_2{)}_3\right(g)+3HCl(g)$

• A.

  1	2	3
  left	right	no shift

• B.

  1	2	3
  right	left	left

• C.

  1	2	3
  no shift	right	left

• D.

  1	2	3
  right	right	no shift

Answer 1

The correct option is D

1	2	3
right	right	no shift

$1.P_4\left(s\right)+6C{l}_2\left(g\right)\rightleftharpoons 4PC{l}_3\left(g\right)$
Decrease in volume leads to an increase in the pressure of the system. So, the equilibrium shifts towards the side with less no. of gaseous molecules. Here, the equilibrium shifts to the right.

$2.PC{l}_3\left(g\right)+C{l}_2\left(g\right)\rightleftharpoons PC{l}_5\left(g\right)$
Here, the equilibrium shifts to the right.

$3.PC{l}_3\left(g\right)+3N{H}_3\left(g\right)\rightleftharpoons P\left(N{H}_2{)}_3\right(g)+3HCl(g)$
Since the no. of gaseous species are same on both the sides, decrease in volume does not affect the equilibrium.