Question

For the reaction

X(g)+3Y(g)⇌3Z(g)

Kp = 2.21×10⁻² at a temperature of 65 ∘C .

Calculate the value of Kc.

Answer 1

The relationship between Kc and Kp is given as follows:

Kc = Kp / (RT)^dn

Where,

Kc = equilibrium constant in terms of molar concentration
Kp = equilibrium constant in terms of partial pressure
R = gas constant (0.08206 L atm K^-1 mol^-1)
T = temperature in Kelvin
dn = (total moles of product - total moles of reactant)

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Part 1: Calculate dn.

dn = (total moles of product - total moles of reactant)
dn = ( 3 – (3+1))
dn = -1

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Part 2: Calculate temperature in Kelvin

T = (273 + T in degree celcius)

T = (273 + 65 ^oC)

T = 338 K

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Part 3: Calculate Kc

Kc = Kp / (RT)^dn

Kc = 2.21×10⁻² / (0.08206 x 338)^-1

Kc = 0.6130

Therefore, value of Kc is 0.6130