Question

At some temperature for the equilibrium PX3(g) + X2(g) # PX5(g) the equilibrium constant is 0.74. At the same temperature the equilibrium constant for PX5(9) + PX3(g) X2(g) is​

Answer 1

Answer: The equilibrium constant for $PX_5(g)\rightarrow PX_3(g)+X_2(g)$ is 1.35

Explanation:

Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as $K_c$  

For the given chemical reaction:

$PX_3(g)+X_2(g)\rightarrow PX_5(g)$

The expression for $K_c$ is written as:

$K_c=\frac{[PX_5]^1}{[PX_3]^1[X_2]^1}$

$0.74=\frac{[PX_5]^1}{[PX_3]^1[X_2]^1}$

For the reverse chemical reaction:

$PX_5(g)\rightarrow PX_3(g)+X_2(g)$

The expression for $K_c'$ is written as:

$K_c'=\frac{[PX_3]^1[X_2]^1}{[PX_5]^1}$

$K_c'=\frac{1}{K_c}=\frac{1}{0.74}=1.35$

The equilibrium constant for $PX_5(g)\rightarrow PX_3(g)+X_2(g)$ is 1.35