Topic 2 Polymrs And Giant Cobalent Structures Flashcards
What are polymers
Lots of small units linked together to from a long molecule that has repeating sections
What are all the atoms in polymers joined together by
Covalent bonds
What are polymers drawn as
A display formula in brackets and the unit on the out side to show how many times the unit repeats
Why is more energy needed to break polymer molecules compared to simple covalent molecules
Because the intermolecular forces between polymers molecules is larger that between simple covalent molecules
What are most polymers at room temperature
Solids
What are the intermolecular forces still weaker than
Than the ionic or covalent bonds
What does having weaker intermolecular forces than ionic or covalent bonds mean
They generally have lower boiling points than ionic or giant molecular compounds
What are giant covalent structures
They are macromolecules
In giant covalent structures what are all the atoms bonded to each other by
Strong covalent bonds
Why does they have very high melting and boiling points
Because a lot of energy is required to break the covalent bonds
Why don’t they conduct electricity
Because they don’t contain charged particles and don’t even conduct electricity when molten ( except for exceptions such as graphite)
What 3 main examples of giant covalent structures should you know
Diamond
Graphite
Silicon dioxide
Structure of diamond
Each carbon forms 4 covalent bonds
In a very rigid giant covalent structure -lattice
Structure of graphite
Each carbon forms 3 covalent bonds
Create layers of hexagons (graphene)
Each carbon atom has one delocalised electron
Structure of silicon dioxide (silica)
What sand is made of - each grain is one giant structure of silicon and oxygen
4 covalent bonds
