Question

Consider the following system at equilibrium where K_c=1.20 × 10^-2 and ΔH°=87.9 kJ / mol at 500 K. 

PCl₅(g) ⇌ PCl₃(g)+Cl₂(g)

The production of P C l₃(g) is favored by:

Indicate True (T) or False (F) for each of the following:

1. increasing the temperature.

2. increasing the pressure (by changing the volume).

3. increasing the volume.

4. adding PCl₅.

5. adding Cl₂.

Answer 1

PCl5 <--> PCl3 + Cl2

1) since, reaction is endothermic
by increasing temperature reaction move in forward direction
so, true
2)
by increasing pressure volume decreases
so, concentration increases
increase concentration will be more on product side because there are two mole of gas product and only one mole of gas reactant
hence, reaction will start moveing in backward direction
so, PCl3 concentration decreases
False
3)
by increasing volume
so, concentration decreases
decreases concentration will be more on product side because there are two mole of gas product and only one mole of gas reactant
hence, reaction will start moveing in forward direction
so, PCl3 concentration increases
True
4)
adding PCl3 will increases the concentration of PCl3
so, reaction will move in reverse direction
false
5)
adding Cl2 will increases the concentration of Cl2
so, reaction will move in reverse direction
false