Solid KClO 3 is taken in a container maintained at constant pressure of 1 atm . Upon heating following equilibria is set. 2 K Cl O 3 ( s ) → 2 K Cl ( s ) + 3 O 2 ( g ) If Δ H ∘ = 25 Kcal / mol a

Question

Solid KClO 3 ​ is taken in a container maintained at constant pressure of 1 atm . Upon heating following equilibria is set. 2 K Cl O 3 ​ ( s ) → 2 K Cl ( s ) + 3 O 2 ​ ( g ) If Δ H ∘ = 25 Kcal / mol and Δ S ∘ = 50 cal / K , at what temperature equilibrium will be establised in the container. (Ignore variation of Δ H 0 and Δ S 0 ​ with temperature.)

TestHub · Accepted Answer

To find the temperature at which equilibrium is established, we need to use the relationship between Gibbs free energy change ( $Δ G^{\circ}$ ), enthalpy change ( $Δ H^{\circ}$ ), and entropy change ( $Δ S^{\circ}$ ):

$Δ G^{\circ} = Δ H^{\circ} - T Δ S^{\circ}$

At equilibrium, $Δ G^{\circ} = 0$ . Therefore,

$0 = Δ H^{\circ} - T Δ S^{\circ}$

Solving for $T$ :

$T = \frac{Δ H ^{\circ}}{Δ S ^{\circ}}$

Given:

$Δ H^{\circ} = 25 k c a l / m o l = 25000 c a l / m o l$

$Δ S^{\circ} = 50 c a l / K - m o l$

$T = \frac{25000 c a l / m o l}{50 c a l / K - m o l} = 500 K$

Therefore, the equilibrium temperature is 500 K.

Final Answer: The final answer is $500 K$

Chemistry - Thermodynamics - II Question with Solution | TestHub

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