Initially, a closed flask contains a mixture of N2 at a partial pressure of 3 atm and H2 at a partial pressure of 5 atm. The mixture reaches equilibrium and the partial pressure of NH3 is 2 atm. What is the value of the equilibrium constant?

The answer to the question is

The value of the equilibrium constant = 2.16×10⁻¹

Explanation:

To solve the question we write out the equation as follows

N₂ (g)+ H₂ (g) → 2NH₃ (g)

Given that

Partial pressure of N₂ (g), PN₂ = 3 atm

Partial pressure of H₂ (g) PH₂= 5 atm

and Partial pressure of NH₃ (g), PNH₃ = 2 atm

Given the partial pressures of the reacting gases at equilibrium such that the partial pressure of N₂ is given by PN₂ and the partial pressure of H₂ is given by PH₂ while the partial pressure of NH₃ is given by PNH₃  the expression for equilibrium constant in terms of partial pressure kp can be written as

  Hence we have

Kp = 2²/(5×3) = 2.16×10⁻¹  

Therefore the equilibrium constant = 2.16×10⁻¹

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.