Question

$0.6$ mole of $\mathrm { PCl } _ { 5 }$, $0.3$ mole of $\mathrm { PCl } _ { 3 }$and $0.5$mole of $\mathrm { Cl } _ { 2 }$are taken in a 1 L flask to obtain the following equilibrium:

If the equilibrium constant for the reaction is $0.2$Predict the direction of the reaction.

• A. Forward direction
• B. Backward direction
• C. Direction of the reaction cannot be predicted
• D. Reaction does not move in any direction.

Answer 1

Answer: (B)

Backward direction

Answer 2

: $\mathrm { PCl } _ { 3 ( \mathrm {~g} ) } + \mathrm { Cl } _ { 2 ( \mathrm {~g} ) }$

$Q _ { c } = \frac { 0.5 \times 0.3 } { 0.6 } = 0.25$

Since $Q _ { c } > K _ { c }$ reaction will proceed in backward direction.