Question

Consider the reaction below.

At 500 K, the reaction is at equilibrium with the following concentrations.

[PCI5]= 0.0095 M

[PCI3] = 0.020

[CI2] = 0.020 M


What is the equilibrium constant for the given reaction?

0.042

0.42

2.4

24

Answer 1

A

Step-by-step explanation:

Answer 2

• First choice: 0.042

Step-by-step explanation:

Given decomposition reaction:

• 1PCl₅ (g) ⇄ 1PCl₃ + 1Cl₂(g)

Equilibrium constant:

• 
  `K_(eq)=([PCl_3]^1[Cl_2]^1)/([PCl_5]^1)`

Stoichiometric coefficients and powers equal to 1 are not usually shown as they are understood, but I included them in order to shwow you how they intervene in the equilibrium expressions: each concentration is raised to a power equal to the respective stoichiometric coefficient in the equilibrium equation.

So, your calculations are:

`K_(eq)=((0.020M)(0.020M))/(0.0095M)=0.042M`