13.1.2 Factors Affecting Lattice Enthalpy

• What is the definition of lattice enthalpy?

  Energy to separate gaseous ions
• Higher ionic charges lead to stronger electrostatic attractions
• Larger ionic radii result in weaker electrostatic attractions.
• What is the formula relating lattice enthalpy to ionic charge and distance?

  $U =$$\frac{kQ_{1}Q_{2}}{d}$
• In the formula for lattice enthalpy, $k$ is a constant
• Lattice enthalpy depends on the charge and ionic radii of the ions.
• Why do higher ionic charges increase lattice enthalpy?

  Stronger electrostatic attractions
• Larger ionic radii result in weaker electrostatic attractions due to increased distance
• The relationship between lattice enthalpy and ionic factors is expressed by the formula U = \frac{kQ_{1}Q_{2}}{d}</latex>
• What are the two key factors affecting lattice enthalpy?

  Charge and ionic radius
• Higher ionic charges create stronger electrostatic attractions, increasing the energy required to separate
• What is the relationship between lattice enthalpy and ionic charge?

  Directly proportional
• MgO has a higher lattice enthalpy than NaCl due to its higher ionic charges.
• MgO has a higher lattice enthalpy because its ions have a charge of +2
• Match the ionic compound with its approximate lattice enthalpy:

  NaCl ↔️ -787 kJ/mol

  MgO ↔️ -3795 kJ/mol
• What are the two main factors affecting lattice enthalpy?

  Charge and ionic radius
• Higher ionic charges increase lattice enthalpy due to stronger electrostatic attractions
• Larger ionic radii decrease lattice enthalpy.
• What is the definition of lattice enthalpy?

  Energy to separate ions
• Higher charges increase lattice enthalpy due to stronger electrostatic attractions
• Larger ionic radii increase lattice enthalpy

  False
• Match the factor with its effect on lattice enthalpy:

  Charge ↔️ Increases

  Ionic Radius ↔️ Decreases
• Higher ionic charges result in stronger electrostatic attractions
• Lattice enthalpy is directly proportional to the product of the ion charges
• Why does MgO have a much higher lattice enthalpy than NaCl?

  Higher charges
• Order the following ionic compounds based on their lattice enthalpy, from lowest to highest:

  1️⃣ NaCl (-787 kJ/mol)

  2️⃣ MgO (-3795 kJ/mol)
• Larger ionic radii weaken electrostatic attractions
• Lattice enthalpy is inversely proportional to the distance between ions
• What happens to the lattice enthalpy as ionic radius increases from LiF to NaCl?

  Decreases
• What is lattice enthalpy defined as?

  Energy to separate gaseous ions
• The electrostatic attraction in lattice enthalpy is described by the formula $U =$$\frac{kQ_{1} Q_{2}}{d}$
• Higher ionic charge increases lattice enthalpy.
• What effect does a larger ionic radius have on lattice enthalpy?

  Decreases it
• Match the factor with its effect on lattice enthalpy:

  Ionic Charge ↔️ Increases lattice enthalpy

  Ionic Radius ↔️ Decreases lattice enthalpy
• Higher ionic charges result in stronger electrostatic attractions, requiring more energy
• Why does MgO have a higher lattice enthalpy than NaCl?

  Greater ionic charges
• Lattice enthalpy is inversely proportional to the distance
• What happens to the lattice enthalpy as the ionic radius increases from LiF to NaCl?

  Decreases
• Why does MgO have a higher lattice enthalpy than NaCl?

  Greater ionic charges
• Higher ionic charges increase electrostatic attractions, raising the lattice enthalpy.