# How do i determine whether a reaction occurs spontaneously

• afcwestwarrior
In summary, spontaneous processes are determined by the change in Gibbs Free Energy (ΔG), which must be negative for a reaction to be spontaneous. This can be calculated using the equation ΔG = ΔH - T * ΔS, where ΔH is the change in enthalpy, ΔS is the change in entropy, and T is the temperature. Both exothermic and endothermic reactions can be spontaneous as long as ΔG is negative.
afcwestwarrior
how do you determine this, do you hve to take exothermic or endothermic reactions into acount or what

well I've anshttp://www.csun.edu/~psk17793/G%20Chemistry/spontaneous_processes.htmwered the question myself, and if u need help here's a link

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Spontaneous processes result in the lowering of the total Gibbs Free Energy (G).

For a chemical reaction to be spontaneous, ΔG must be negative.
It is possible to have both exothermic (ΔH < 0) as well as endothermic (ΔH > 0) spontaneous reactions.

ΔG = ΔH – T * ΔS
Where ΔG is the change in the Gibbs Free Energy, ΔH is the change in enthalpy, ΔS is the change in entropy, and T is the temperature the reaction occurs at (in Kelvin).

## What factors determine whether a reaction occurs spontaneously?

The spontaneity of a reaction is determined by two main factors: the change in Gibbs free energy (ΔG) and the change in entropy (ΔS). If ΔG is negative and ΔS is positive, then the reaction is spontaneous.

## How do I calculate the change in Gibbs free energy (ΔG) for a reaction?

The change in Gibbs free energy can be calculated using the equation ΔG = ΔH - TΔS, where ΔH is the change in enthalpy (heat content) and ΔS is the change in entropy. A negative value for ΔG indicates a spontaneous reaction.

## What role does temperature play in determining spontaneity of a reaction?

The temperature affects the value of ΔG, and thus plays a crucial role in determining the spontaneity of a reaction. In general, as temperature increases, a reaction becomes more likely to be spontaneous, since the increase in temperature increases the value of TΔS in the ΔG equation.

## Can a non-spontaneous reaction be made spontaneous?

Yes, a non-spontaneous reaction can be made spontaneous by altering the conditions of the reaction. This can be achieved by changing the temperature, pressure, or concentrations of reactants and products. The goal is to change the values of ΔG and ΔS to make the reaction spontaneous.

## What is the relationship between spontaneity and equilibrium?

In a spontaneous reaction, the reactants are converted into products until equilibrium is reached. At equilibrium, the forward and reverse reactions occur at equal rates, and there is no further change in the concentrations of reactants and products. However, not all spontaneous reactions reach equilibrium, as some may go to completion (all reactants are converted to products) or reach a state of dynamic equilibrium (where the concentrations of reactants and products remain constant).

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