Ionic bonding

Question 1

ionic bonding

Answer 1

• the electrostatic force of attraction between two oppositely charged ions.
• occurs between a metal and a non-metal.
• the metal cation and non-metal anion attract each other.
• electrons are transferred from the metal to the non-metal.

Question 2

formation of ionic bonds

Answer 2

METALS:
- lose their outermost electrons to form positively charge ions.
- become isoelectronic (same electron configuration) with the last noble gas.

NON METALS:
- gain electrons to form negatively charged ions.
- become isoelectronic with the next noble gas.

They become ENERGETICALLY STABLE.

Question 3

The nature and structure of ionic bonds

Answer 3

• every ion in the lattice is attracted to every other oppositely charge ion.
• the charge of an ion acts in all directions
• they are non-directional bonds.
• equal in strength in all directions

Structure :

• the ion with the smallest number of shells will be represented as a small sphere.
• coordination number ~ how many ions of the opposite charge an ion is surrounded by.
• form a repeating pattern leading to the formation of a lattice structure.

ionic bonds have a GIANT IONIC LATTICE structure.

• giant structures ~ the number of ions is unknown

Question 4

Properties of ionic bonding

Answer 4

HIGH MP & BP:
A great deal of energy needed to overcome the strong electrostatic forces of attraction and therefore high temperatures are required.

The greater the charges of ions and the SMALLER the ionic radii, the greater the electrostatic force of attraction, therefore more energy and higher temperatures required.

SOLUBLE IN POLAR SOLVENTS:
- ions are stabilised by the electrostatic forces of attraction with water molecules.

• water molecules have partial charges , H delta + and O delta - ,due to being a polar molecule.
• water molecules surround the ions which overcome the electrostatic attraction between ions.
• if the charge of the ions increase, the solubility decreases ~ the water molecules can no longer overcome the electrostatic forces of attraction.

DO NOT CONDUCT ELECTRICITY AS SOLIDS:

• ions are locked in place by the electrostatic forces of attraction ~ cannot carry the charge.
• if melted or dissolved in water they can now conduct as the ions are free to move.

BRITTLE:
ions of the same charge are placed opposite one another when a force is applied and the planes of ions then repel each other.

Question 5

ionic equations

Answer 5

METALS:
x ——– x+ + e-
lose electrons to become positively charged.

NON-METALS:
x + e- ——– x-
gain electrons to become negatively charged.