5.8 Predicting Whether A Reaction Will Be Spontaneous

Question 1

What is a spontaneous reaction?

Answer 1

One that occurs without any outside influence.

Question 2

What are the conditions for a reaction to be spontaneous?

Answer 2

The change in Gibbs free energy for the reaction must be negative.

Question 3

What is the equation for gibbs free energy?

Answer 3

delta G = delta H - TdeltaS

Question 4

What happens to the spontaneity of a reaction for which delta S is positive?

Answer 4

It will get more spontaneous as temperature increases. If delta S is positive - T delta S will be negative and will become more negative as T increases. This means that deltaG will become more negative as T increases.

Question 5

What amounts Gibbs free energy is there in the equilibrium mixture compared to the pure reactants or pure products?

Answer 5

The equilibrium mixture always have a lower Gibbs free energy the either the purchase products of pure reactants.

Question 6

What will the gibbs free energy be for a conversion of pure reactants or pure products into the equilibrium mixture?

Answer 6

Delta G will be negative so the process will be spontaneous.

Question 7

What does a more negative value of delta G mean for the equilibrium position?

Answer 7

The more negative delta G for a reaction the closer the potion of equilibrium lies towards products.

Question 8

What does a more positive value of delta G mean for the equilibrium position?

Answer 8

The more positive the value the closer the position of equilibrium lies towards the reactants.