Topic 8&9 (ionic and covalent bonding) Flashcards
What is an ionic bond?
A bond between oppositely charged ions, where an electron is transferred.
What forces are ions attracted with?
Electrostatic forces
What is the arrangement of ionic compounds?
Giant ionic lattice
Why do ionic compounds have high melting points?
Ionic compounds are arranged in giant ionic lattices. A lot of energy is required to overcome the strong electrostatic forces of attraction between oppositely charged ions, so they have high melting points.
Are ionic compounds soluble in water and organic solvents?
Ionic compounds are usually soluble in water and insoluble in organic solvents.
Do ionic compounds conduct electricity in the solid state?
No. In solid state, the ions are fixed in position in the giant ionic lattice structure by strong electrostatic forces, so there are no mobile charge carriers/
Do ionic compounds conduct electricity in the molten and aqueous states?
Yes. In molten and aqueous states, the ions break free from the giant ionic structure and are free to move and conduct electricity.
What is a covalent bond?
Covalent bonds are bonds formed when two atoms share pairs of electrons.
Compare the bonds between chlorine, oxygen and nitrogen.
Chlorine atoms share one pair of electrons. (single covalent bond)
Oxygen atoms share two pairs of electrons. (double covalent bond)
Nitrogen atoms share three pairs of electrons. (triple covalent bond)
Why do simple molecular substances have low melting and boiling points?
Simple molecular substances have weak intermolecular forces of attraction between the molecules. Little energy is needed to overcome these forces of attraction, so they have low melting and boiling points.
Why do simple molecular substances not conduct electricity?
Simple molecular substances exist as neutral molecules so there are no mobile charge carriers to conduct electricity.
Are simple molecular compounds soluble in water and organic solvents?
Simple molecular compounds are usually insoluble in water and soluble in organic solvents.
Why does magnesium oxide have a higher boiling point than sodium oxide?
Magnesium oxide has two electrons being transferred, while sodium oxide only has 1. Therefore, the ionic bond between magnesium and oxide ions is stronger.
What bonds are present in ammonium chloride?
Both ionic and covalent bonds
