Thread: chemistry questions

1. what is the value of the equilibrium constant at for the decomposition of phosporus pentachloride gas to phosphorus trichloride gas and chlorine gas? At equilibrium,





4. In the haber process of synthesizing ammonia, the value of K is for the reaction at . In a sealed container at equilibrium at the concentations of and are measured to be 0.50 mol/L and 1.50mol/L respectively. Write the equilibrium constant equation and calculate the equilibreum concentration of )

1. what is the value of the equilibrium constant at for the decomposition of phosphate pentachloride gas to phosphorus trichloride and chlorine gas? At equilibrium,

The reaction is:
PCl5 <---> PCl3 + Cl2
At equilibrium: PCl5=(4.3 x 10^-4) PCl3 =0.014 Cl2= 0.014

Therefore,
Equilibrium constant K
= 0.014 x 0.014/(4.3 x 10^-4)
= 0.000196/(4.3 x 10^-4)
=0.4558

Originally Posted by fardeen_gen

The reaction is:
PCl5 ---> PCl3 + Cl2
Initial conc. : 1 0 0
At equilibrium: 1 - x x x

Therefore, according to given data, x = 0.014 mol/L

Therefore,
Equilibrium constant K
= x.x/(1 - x)
= x^2/(1 - x)
= (0.014)^2/(1 - 0.014)
= 0.000196/0.086
= 0.0023

You were missing a bit of info, i edited, sorry.

4. In the haber process of synthesizing ammonia, the value of K is for the reaction at . In a sealed container at equilibrium at the concentations of and are measured to be 0.50 mol/L and 1.50mol/L respectively. Write the equilibrium constant equation and calculate the equilibreum concentration of )

N2 + 3H2 <---> 2NH3
Equilibrium concentration: [H2] = 0.50 M, [N2] = 1.50 M
Let the equilibrium concentration of NH3 be x M

Therefore,
Equilibrium constant equation: (By law of mass action)
K = [NH3]^2/([H2]^3 x [N2])
8 x 10^-7 = x^2/((0.5)^3 x (1.5))
x^2 = (8 x 10^-7) x (0.125) x (1.5)
x^2 = 1.5 x 10^-7
x = 3.87 x 10^-4

Equilibrium constant equation: (By law of mass action)
K = [NH3]^2/([H2]^3 x [N2])
x^2 = (8 x 10^-7) x (0.125) x (1.5)

these

Can you quote the exact lines please?

EDIT:
By the Gulbarg-Waage law of mass action:
For a reaction:

where, [S], [T], [A], [B] are equlibrium concentrations and α,β, σ, τ are molar coefficients(number of moles of the particular element or compound, for example, σ moles of S are formed in the above equation)



Now, since

the value of K is 8 x 10^-7 for the reaction at 400 degree celsius

, therefore as the required reaction also takes place at 400 degree celsius, we can use the above value of K and plug it into the equilibrium constant equation. Then all I have done is some cross multiplication(using the given values) to get concentration of NH3(which I assumed to be x moles/L)

Equilibrium constant equation: (By law of mass action)
K = [NH3]^2/([H2]^3 x [N2])
8 x 10^-7 = x^2/((0.5)^3 x (1.5))
x^2 = (8 x 10^-7) x (0.125) x (1.5)

these

Originally Posted by fardeen_gen

Can you quote the exact lines please?

EDIT:
By the Gulbarg-Waage law of mass action:
For a reaction:

where, [S], [T], [A], [b] are equlibrium concentrations and α,β, σ, τ are molar coefficients(number of moles of the particular element or compound, for example, σ moles of S are formed in the above equation)

thanks for your time, and happy new year!