Question

Born-Haber cycle is used to determine (1) lattice energy (2) electron affinity (3) tonisation energy (4) any of these

Short answer

The Born-Haber cycle is used to determine lattice energy, ionization energy, and electron affinity.

Step-by-step solution

- Understand the Born-Haber Cycle

The Born-Haber cycle is a thermochemical cycle used to analyze the formation of an ionic compound from its constituent elements.

- Identify the Components Involved

The cycle involves several steps including the sublimation of the metal, the ionization of the metal atoms, the dissociation of the non-metal molecules, and the electron affinity of the non-metal atoms.

- Recognize the Lattice Energy

The lattice energy is derived from the Born-Haber cycle as it represents the energy released when the ions come together to form the ionic solid.

- Determine What the Cycle Can Calculate

The Born-Haber cycle is used to determine the lattice energy of an ionic compound. It is also crucial in calculating other thermodynamic quantities such as ionization energy and electron affinity.

- Answer the Question

Given the components and purposes of the Born-Haber cycle, it can be concluded that it is used to determine lattice energy, ionization energy, and electron affinity.

Key concepts

Lattice Energy

Lattice energy is the energy released when oppositely charged ions come together to form a solid. This concept is essential in understanding ionic compounds as it shows how strong the bonds are within the compound. To calculate lattice energy using the Born-Haber cycle, you need several steps and intermediate values:

• Sublimation energy: Energy required to convert a solid metal into gaseous atoms.
• Bond dissociation energy: Energy to break the bond in a non-metal molecule.
• Ionization energy: Energy to remove an electron from metal atoms.
• Electron affinity: Energy change when non-metal atoms gain electrons.

Lattice energy is always a large negative value because it's an exothermic process. High lattice energy means a more stable ionic compound.
The Born-Haber cycle helps us visualize these energy changes, giving a clearer picture of how ionic compounds form and why they are so stable.

Electron Affinity

Electron affinity is the energy change that occurs when an electron is added to a neutral atom. This process is usually exothermic as atoms release energy when gaining an electron to achieve a stable electron configuration.

• First Electron Affinity: Energy change when one electron is added.
• Second Electron Affinity: Additional energy change when another electron is added.

For example, when a chlorine atom gains an electron to form a chloride ion, the electron affinity is negative because energy is released. In the Born-Haber cycle, electron affinity is a crucial step as it represents the electron gain by the non-metal part of the ionic compound.
Understanding electron affinity helps you predict how atoms will interact, showing the tendency of atoms to form anions in ionic compounds.

Ionization Energy

Ionization energy is the energy needed to remove an electron from an atom, creating a cation. It is usually endothermic, meaning the process consumes energy. The Born-Haber cycle uses ionization energy to understand the formation of metal cations in ionic compounds.

• First Ionization Energy: Energy to remove the first electron from a neutral atom.
• Second Ionization Energy: Energy required to remove a second electron from a +1 cation.

Metals typically have low ionization energies, making them more likely to lose electrons and form cations. This property is essential in forming ionic bonds, as the energy provided to remove the electron is later compensated by forming the ionic compound.
By analyzing ionization energies, you can predict how easily an element will form a positive ion, which is integral in completing the Born-Haber cycle.