Ionic Bonding Flashcards
What does the perfect ionic model state?
Ionic compounds are composed of perfectly spherical cations and anions arranged in a lattice.
What is ionic bonding?
Many strong electrostatic forces of attraction formed between oppositely charged ions (all the cations and anions) in a lattice.
What is the relationship between electrostatic forces of attraction and ionic bonding?
The stronger the attraction, the stronger the ionic bonding.
How would non-metals on their own be identified as?
How would you say these?
F⁻
Se²⁻
P³⁻
N³⁻
Br⁻
S²⁻
As³⁻
you add the suffix ‘-ide’ at then end of the substance name.
F⁻ > fluoride
Se²⁻ > selenide
P³⁻ > phosphide
N³⁻ > nitride
Br⁻ > bromide
S²⁻ > sulfide
As³⁻ > arsenide
What is a polyatomic ion? Give an example.
When an ion is made up of one or more atom.
MnO₄⁻ > manganate ion
What does empirical mean?
‘Experimental’
Describe why an ionic compound can or cannot carry charge in either solid, liquid or gas state.
Solid =
Ions are not free to move - cannot carry charge - can’t conduct electricity.
Liquid =
Ions are free to move - can carry charge - can conduct electricity.
Gas =
Ions are separated and exist as ion pairs - cannot carry charge - cannot conduct electricity.
What does the term ‘isoelectronic’ mean? Give examples.
When ions have an equal number of electrons.
E.G… these ions all have 10 electrons in total.
Na⁺
Mg²⁺
Al³⁺
N³⁻
O²⁻
F⁻
‘Iso’ is Greek for ‘equal’.
For isoelectronic ions, how can we identify the smallest ion?
The larger the nuclear charge, the smaller the ion.
Which ionic compound do we expect to have a higher melting point and why?
NaCl or KCl?
NaCl
because sodium has the same charge as potassium, but is smaller in size so there is a stronger electrostatic force of attraction and thus stronger ionic bonding, requiring more energy to overcome.
Draw a diagram to show the structure of an ionic compound.
Ionic lattice = (Need AT LEAST 9 ions)
Oppositely charged ions in a 9x9 structure.
Anions are bigger than cations.
Include 1+,2+ / 1-, 2- charges in the circles.
Label which circles are the metal / non-metal.
Draw a diagram to show the structure of a metallic substance.
Metallic lattice = (Need AT LEAST 9 ions)
9x9 positive ions next to each other.
Include 1+ / 2+ / 3+ in the circles.
For each ion, show the delocalised electrons around it.
E.G.
Mg2+ has 2 delocalised electron per ion. So in a 9x9 I would draw 18 electrons.
List everything about ionic bonding you can remember.
Metal & non-metal - forms cations/anions.
ALL ionic compounds form a GIANT IONIC CRYSTAL LATTICE structure.
MANY STRONG electrostatic forces of attraction.
Electrons are TRANSFERRED.
What are the properties of ionic compounds?
High melting / boiling point
Brittle
Soluble in water
Can conduct electricity when molten or aqueous
Cannot conduct electricity when solid.
Why do ionic compounds have high melting and boiling points? [2 marks]
There are MANY STRONG electrostatic forces of attraction BETWEEN oppositely charged ions in the IONIC LATTICE - needs a lot of energy to overcome these attractions.
Why are ionic compounds brittle? [2 marks]
When a horizontal FORCE is applied to lattice, the LAYERS of ions move and SLIDE over each other.
Ions of same charge are next to each other, so they REPEL each other and the crystal breaks up.
Why can ionic compounds conduct electricity when molten or in solution? [2 marks]
Ions are free to MOVE THROUGH the substance, meaning ions are able to carry CHARGE and conduct electricity.
Why are ions arranged in an ionic lattice structure?
To optimise the number of electrostatic forces of attraction.
How are cations formed?
When a metal loses an electron.
How are anions formed?
When a non-metal gains an electron.
Which cation is the only non-metal?
Ammonium (NH₄⁺)
What is a compound ion? Give examples.
An ion made up of a group of atoms.
E.G.
Ammonium
Sulfate
Nitrate
Carbonate
Hydroxide
What does ‘monoatomic’ mean?
Consisting of only 1 atom.
What is the definition of a ‘crystal’?
The ordered arrangement of ions in a material.
Ionic compounds are crystals.
