Question

CHEMISTRY-IB
2 mole of PCI, is heated in a one litre vessel. If
PCI, dissociates to the extent of 80%, the
equilibrium constant for the dissociation of PCI,
is
1) 2X10* 2) 6.4 3) 0.67 4) 0.32​

Answer 1

Answer:

PCl

5

⇌PCl

5

(g)+Cl

2

(g)

2mole 0moles 0moles 80% dissociation.

2α 0 0

2(1−α) 2α 2α α=0.8mol.

Volume of equilibrium mixture V=1L

[PCl

5

(g)]=

V

2(1−α)

=

1

2(1−0.8)

=0.4molL

−1

[PCl

3

(g)]=

V

2α)

=

1

2(0.8)

=1.6molL

−1

[Cl

2

(g)]=

V

2α)

=

1

2(0.8)

=1.6molL

−1

Equilibrium constant,

K

c

=

[PCl

5

(g)]

[PCl

3

(g)][Cl

2

(g)]

=

0.4

1.6×1.6

=6.4