Ionic Bonding

Question 1

Iconic Compounds

Answer 1

Crystals made up of metal and non-metal atoms chemically joined by an ionic bond.

• An ionic bond results when metallic atoms combine with non-metallic atoms to form an ionic lattice.
• A metallic bond results when metallic atoms combine to form a metallic lattice.
• A covalent bond results when non-metallic atoms combine to form either molecules or covalent lattices.

Question 2

How do ionic bonds form

Answer 2

Metallic ions are low in electronegativity and will lose electrons to become stable. Non-metallic ions have high electronegativities and will gain electrons to become stable.

Question 3

Electronegativity Trends

Answer 3

electronegativity generally increases as you move from left to right across a period and decreases as you move down a group. Most electronegative is top left (fluorine), least electronegative is bottom right (francium)

Question 4

Ionic bonds

Answer 4

Formed by the strong force of attraction between positive and negative ions. The bonded form is more stable that unbonded ions, with completely different properties from the original elements. Sodium is highly reactive, while chloride is a poisonous gas, however sodium chloride is salt. The chemical formula given for an ionic compound is the empirical formula as it is the simplest ratio of ions in the lattice.

Question 5

Structure of ionic lattices

Answer 5

Ionic compounds form crystals that are composed of three-dimensional arrays of positive metal ions and negative non-metal ions.

These arrays are called ionic network lattices and are held together by the strong electrostatic attraction — the ionic bond

The ions are arranged in a regular repeating pattern throughout the crystal to achieve the most stable arrangement. Each cation to anions and vice versa.

Question 6

Properties of ionic compounds

Answer 6

The electrostatic forces of attraction holding them together are strong. Therefore:

• Ionic compounds are are usually crystalline solids due to the lattice structure
• have high melting and boiling points, because a large amount of energy is needed to break ionic bonds
• do not conduct electricity in solid form as there are no free moving electrons (carriers of charge)
• are hard/durable due to the strong ionic bonds holding ions together
• dissolve in water to form ions (dissociate) as water molecules move between ions and disrupt the rigid crystal structure
• conduct electricity when molten or in aqueous solution as ions dissociate from the lattice and can move freely to conduct an electric current. The solution is called an electrolyte

Question 7

Brittleness of Ionic compounds

Answer 7

• Ionic compounds are brittle. When a force is applied, this causes repulsion between like charges which shatters the crystal, but a clean split can be achieved if made along the plane.

Question 8

Answer 8

Question 9

Polyatomic ions

Answer 9

Regular ions are monoatomic ions formed from a single atom while polyatomic ions are ions formed from a group of two or more atoms covalently bonded.

Question 10

Answer 10

Question 11

Ions with Variable Charge

Answer 11

a.) Name the compound CuO
Ans: copper (II) oxide In order to determine the charge on the metal ion, we need to work backwards from the known charge on the anion.
The charge on the oxide ion is 2–.
Therefore, for a net charge of zero, the charge on the Cu ion must be 2+. The compound is, therefore, named copper(II) oxide.