Ib Chemistry Hl Topic 15

1. Define and apply the terms lattice enthalpy and electron affinity.

Lattice enthalpy is the energy released when converting gaseous ions into a solid compound.

Electron affinity is the energy required to remove an electron from a negatively charged gaseous ion.

Lattice enthalpy is the energy needed to convert one mole of gas into a solid compound.

Attice enthalpy is the energy required to convertone mole of the solid compound into gaseous ions. The electron affinity is the enthalpy change when onemole of gaseous atoms or anions gains electrons to form amole of negatively charged gaseous ions.

About This Quiz

Explore advanced concepts in chemical equilibrium with this focused assessment, designed for IB Chemistry HL students. This quiz enhances understanding of dynamic equilibria, Le Chatelier's Principle, and reaction... see morequotients, crucial for academic success in higher-level chemistry. see less

2. Explain how the relative sizes and the charges of ions affect the lattice enthalpies of different ionic compounds.

The relative value of the theoretical lattice enthalpyincreases with higher ionic charge and smaller ionicradius due to increased attractive forces.

Higher lattice enthalpies are observed in ionic compounds with lower charges and larger radii.

The lattice enthalpy decreases when ions have opposite charges and larger radii.

Ionic compounds with similar charges and larger radii have higher lattice enthalpies.

3. State and explain the factors that increase the entropy in a system.

Entropy is a measure of the orderliness of a system

Increasing the temperature of a system decreases its entropy

An increase in pressure always leads to an increase in entropy

Entropy: The disorder of a system is measured as its entropy. Scattered marbles have a higher entropythan gathered marbles. Entropy change: The change in disorder of a system. When going from more moles of gas to lessmoles there is a decrease in entropy, and vice versa.
Increase Entropy:
Increase VolumeDecrease PressureSolid -> Liquid -> GasIncrease TemperatureIncrease Number of Particles / Moles
Decrease Entropy:
Decrease VolumeIncrease PressureGas -> Liquid - > Solid more compactDecrease tempDecrease Number of Particles / Moles

The correct answer explains that entropy is actually a measure of disorder, increasing pressure does not always increase entropy, and increasing temperature typically increases entropy.

Explanation

The correct answer explains that entropy is actually a measure of disorder, increasing pressure does not always increase entropy, and increasing temperature typically increases entropy.

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