For the equilibrium PCl5(g)⇌PCl3(g)+Cl2(g), the equilibrium constant Kp is 0.497 at 500K. A gas cylinder at 500K is charged with PCl5(g) at an initial pressure of 1.66atm. Determine the equilibrium pressure of all species at this temperature.

Respuesta :

Answer:

[tex]p_{PCl_3}=0.693atm\\\\p_{Cl_2}=0.693atm\\\\p_{PCl_5}=0.967atm[/tex]

Explanation:

Hello,

In this case, for the given reaction, the equilibrium expression is:

[tex]Kp=\frac{p_{PCl_3}p_{Cl_2}}{p_{PCl_5}}[/tex]

But in terms of the reaction extent [tex]x[/tex] can also be written as:

[tex]Kp=\frac{x*x}{p_0-x}[/tex]

Whereas the initial pressure is 1.66 atm. Thus, we write:

[tex]0.497=\frac{x^2}{1.66atm-x}[/tex]

And solving for [tex]x[/tex] we obtain:

[tex]x=0.693atm[/tex]

Therefore, the pressure of each species at equilibrium is:

[tex]p_{PCl_3}=x=0.693atm\\\\p_{Cl_2}=x=0.693atm\\\\p_{PCl_5}=1.66atm-0.693atm=0.967atm[/tex]

Best regards.