Relationship between G, S and H Flashcards
(24 cards)
What does deltaG represent in thermodynamics?
DeltaG represents the change in Gibbs free energy during a process.
What does a negative deltaG indicate?
A negative deltaG indicates that a process is spontaneous and can occur without external energy.
What is the significance of deltaH in thermodynamics?
DeltaH represents the change in enthalpy, indicating the heat absorbed or released during a reaction.
Is deltaH positive or negative for an exothermic reaction?
DeltaH is negative for an exothermic reaction.
What does deltaS represent in thermodynamics?
DeltaS represents the change in entropy, which measures the disorder or randomness of a system.
True or False: A positive deltaS indicates an increase in disorder.
True
How are deltaG, deltaH, and deltaS related by the Gibbs free energy equation?
The relationship is given by the equation: deltaG = deltaH - T*deltaS.
What does a positive deltaG indicate?
A positive deltaG indicates that a process is non-spontaneous and requires energy input.
Fill in the blank: If deltaH is negative and deltaS is positive, then deltaG is __________ at all temperatures.
negative
What does it mean if deltaS is negative?
A negative deltaS indicates a decrease in disorder or an increase in order in the system.
In the context of Gibbs free energy, what does ‘spontaneous’ mean?
Spontaneous means that a process can occur naturally without external energy input.
What is the unit of measurement for deltaH?
The unit of measurement for deltaH is typically kilojoules per mole (kJ/mol).
True or False: An increase in temperature can affect the spontaneity of a reaction.
True
What happens to deltaG as temperature increases if deltaH is positive and deltaS is negative?
DeltaG will become more positive as temperature increases, making the reaction less spontaneous.
What does it mean for a reaction to be at equilibrium in terms of deltaG?
At equilibrium, deltaG is equal to zero.
Fill in the blank: For a reaction, if deltaH is positive and deltaS is positive, deltaG will be __________ at high temperatures.
negative
What is the physical interpretation of deltaS in a chemical reaction?
DeltaS indicates the change in the number of microstates or configurations available to a system.
True or False: DeltaH and deltaS can both determine the spontaneity of a reaction.
True
What does it mean for a process to be endothermic in terms of deltaH?
An endothermic process has a positive deltaH, meaning it absorbs heat from the surroundings.
What is the effect of a catalyst on deltaG?
A catalyst does not change deltaG; it only speeds up the rate of the reaction.
Fill in the blank: A reaction with a large negative deltaH and a large positive deltaS will likely have a deltaG that is __________.
negative
What role does temperature play in the Gibbs free energy equation?
Temperature affects the contribution of entropy (deltaS) to the Gibbs free energy change (deltaG).
In a spontaneous reaction, what is the relationship between deltaG and the equilibrium constant (K)?
A spontaneous reaction corresponds to a K value greater than 1, indicating that deltaG is negative.
True or False: DeltaH is always positive for reactions that require heat.
True
