The two common chlorides of phosphorus, pcl3, and pcl5, both important for the production of the other phosphorus compounds, coexist in equilibrium through the reaction
pcl3(g) + cl2(g) = pcl5(g)
at 250 ᵒc , an equilibrium mixture in a 25.0 l flask contains 0.105 g pcl5, 0.220 g pcl3 and 2.12 g of cl2. what are the values of
a) kc
b) kp for this reaction at 250 ᵒc ?

For a: The value of for the given reaction is 271.6

For b: The value of for the reaction is 6.32

Explanation:

To calculate the number of moles, we use the equation:

     .....(1)

Given mass of = 0.105 g

Molar mass of = 208.24 g/mol

Putting values in equation 1, we get:

Given mass of = 0.220 g

Molar mass of = 137.33 g/mol

Putting values in equation 1, we get:

Given mass of = 2.12 g

Molar mass of = 71.0 g/mol

Putting values in equation 1, we get:

Volume of the flask = 25.0 L

For the given chemical equation:

The equation used to calculate concentration of a solution is:

The expression of for above reaction follows:

We are given:

Putting values in above equation, we get:

Hence, the value of for the given reaction is 271.6

Relation of with is given by the formula:

where,

= equilibrium constant in terms of partial pressure = ?

= equilibrium constant in terms of concentration = 271.6

R = Gas constant =

T = temperature =

= change in number of moles of gas particles =

Putting values in above equation, we get:

Hence, the value of for the reaction is 6.32