Question

What types of experiments can be carried out to determine if a reaction is spontaneous? Does spontaneity have any relationship to the final equilibrium position of a reaction? Explain.

Short answer

ΔG needs to calculate to know the spontaneity of the reaction if ΔG is negative the reaction is spontaneous and if ΔG is positive then the reaction will be spontaneous in opposite direction.

At equilibriumΔG =0.

Step-by-step solution

Spontaneity of the Reaction

ΔG is the key term in determining the spontaneity of the reaction and ΔG of a reaction can be calculated using the given equation,

$\mathbf{\Delta G}\mathbf{=}\mathbf{\Delta H}\mathbf{-}\mathbf{T\Delta S}$

If ΔG of the reaction comes out to be negative the reaction is said to be spontaneous and if ΔG is comes out positive then the reaction will be spontaneous in opposite direction.

 Step 2: Spontaneity and Final Equilibrium

For a reaction to be at equilibrium ΔG is equal to zero. So, following relation is true for equilibrium,

$\begin{array}{l}\mathbf{\Delta G}\mathbf{=}\mathbf{\Delta H}\mathbf{-}\mathbf{T\Delta S}\mathbf{=}\mathbf{0}\\ \mathbf{\Delta H}\mathbf{=}\mathbf{T\Delta S}\end{array}$