What factors affect the value of lattice enthalpy?

The factors affecting lattice enthalpy values are:

  1. Ionic charge.
  2. Ionic radius.


Lattice enthalpy becomes more negative as ionic charge increases and ionic radius decreases.

Answer in your head, out loud, or on paper, then tap the card to flip.

What is the link between ionic bond strength and lattice enthalpy?

The more negative the lattice enthalpy value, the stronger the ionic bonding.

Answer in your head, out loud, or on paper, then tap the card to flip.

What is the equation that represents the enthalpy change of atomisation of chlorine?

12\frac{1}{2}Cl2(g) ➔ Cl(g)

Answer in your head, out loud, or on paper, then tap the card to flip.

What is the equation for the first electron affinity of sulfur?

S(g) + e- ➔ S-(g)

Answer in your head, out loud, or on paper, then tap the card to flip.

Why are first ionisation energies endothermic?

First ionisation energies are endothermic because energy must be supplied to overcome the electrostatic attraction between the nucleus and the electron being removed.

Answer in your head, out loud, or on paper, then tap the card to flip.

Define the term Brønsted-Lowry base.

A Brønsted-Lowry base is a proton acceptor. 


For example, NH3 acts as a Brønsted-Lowry base according to the equation:

NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH-(aq)

Answer in your head, out loud, or on paper, then tap the card to flip.

Define lattice enthalpy (ΔH⦵latt).

Lattice enthalpy is the enthalpy change that occurs when one mole of an ionic compound is formed from its gaseous ions under standard conditions.


For example, the equation for the lattice enthalpy of formation of NaCl is:

Na+(g) + Cl-(g) ➔ NaCl(s)

Answer in your head, out loud, or on paper, then tap the card to flip.

Explain whether lattice enthalpies have positive or negative values.

Lattice enthalpies always have negative values because the process is exothermic, as new bonds are formed between the oppositely charged ions.

Answer in your head, out loud, or on paper, then tap the card to flip.