At 25°C, gaseous decomposes to and to the extent that 14.5% of the original (by moles) has decomposed to reach equilibrium. The total pressure (at equilibrium) is 0.670 atm. Calculate the value of for this system.

The value of Kp for the system = 0.0128 atm

Explanation:

Let, the gaseous substance is SO₂Cl₂

                               SO₂Cl₂     ⇄        SO₂       +        Cl₂

Initially                      x                            0                   0

At equilibrium   (x - 14.5%x)                14.5%x           14.5%x

                        = 85.5 % x

Total moles of gases at equilibrium

                = 85.5 % x + 14.5%x + 14.5%x

                = 114.5 % x

Partial pressure of SO₂ () =

Partial pressure of Cl₂

Partial pressure of SO₂Cl₂

So,

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.