Lattice enthalpy Flashcards
What is enthalpy change?
The heat transferred in a reaction at a constant temperature.
What does a negative enthalpy value indicate?
An exothermic reaction.
What does a positive enthalpy value indicate?
An endothermic reaction.
What is lattice enthalpy?
When one mole of a solid ionic compound is formed from its gaseous ions under standard conditions.
What two factors lattice enthalpy?
Ionic charge and Ionic radius.
What does a higher ionic charge result in?
Stronger electrostatic attractions.
More energy is released.
More negative enthalpy.
What does a smaller ionic radius result in?
Higher charge density
Ions can pack together more closely.
Increases the electrostatic attractions between ions.
More negative enthalpies.
Is lattice enthalpy endothermic or exothermic?
Exothermic
What is entropy?
Measures the degree of disorder or randomness in a system.
What does a high entropy value indicate?
A high level of disorder.
Why do systems naturally tend toward states of higher entropy?
Increases entropy provides energetic stability.
What are the two factors affecting entropy?
Physical state and number of particles.
What happens to the entropy when the numbers of particles increases?
It increases as more particles allows for greater number of possible arrangements of particles.
What is gibbs free energy change?
The overall change in energy in a chemical reaction.
How do you calculate entropy change?
Entropy of products - entropy of reactants.
