Ionic bonding Flashcards
what are ionic compounds?
metals and non-metals bonded together
what are common properties of ionic compounds?
High melting and boiling points (solids at room temperatures).
Crystalline solid.
Conducts electricity when melted or dissolved in water but not when solid.
Hard but brittle (not malleable or ductile).
Vary in solubility in water.
what is ionic bonding?
a strong electrostatic bond between the cations and anions called ionic bonding
what do ionic compounds form?
crystalline lattices resulting in a regular 3D arrangement.
The arrange themselves in a stable configuration with oppositely charged ions together.
what does the strength of the bonding depend on?
the size of the ions and the change on the anions and cations
why do they have high melting and boiling points?
Large amounts of energy are needed to break the strong electrostatic forces of attraction (ionic bonds).
why are they hard and brittle?
The surface is not easily scratched as a strong force is needed to disrupt the strong electrostatic forces.
The crystal is hard because of this.
If a strong force is applied it will shatter.
This is because the distortion of the crystal causes like charges to come together causing the crystal to shatter.
why do they conduct electricity?
Conduct when molten or aqueous but not when solid.
For conductivity the charged particles must be free moving and in molten and aqueous states this is true.
A solution or molten substance that conducts electricity is called an electrolyte.
what is their solubility?
There are a large range.
To be soluble the ions must be able to break away from the lattice and mix with water.
Solubility depends on the strength of the forces of attraction between the positive and negative ions and water molecules and the ions.
what are uses for ionic compounds?
Calcium phosphate is a constituent of bone tissue that gives it strength- hardness.
Magnesium oxide is used to line furnaces- high melting and boiling points.
Ammonium chloride is used as an electrolyte in dry cell batteries- electrical conductivity.
Sodium hydrogen carbonate makes cakes rise.
Sodium chloride is a flavouring agent.
Sodium hypochlorite is used in swimming pools to kill microorganisms.
how do you write chemical formula?
Write the cation first with its electrovalency.
Write the anion with its electrovalency.
Determine the number of each ion required to produce an overall charge of zero on the compound (use swap and drop). There should be no charges.
Write the formula using subscripts only.
monatomic
one element
polyatomic
the ion has more than one element. If more than one is needed in a formula, brackets are needed.
ide
monoatomic
ite
compound with the lower amount of oxygen
