C2 - Polymers And Giant Covalent Structures

Question 1

What do polymers and giant covalent structures have in terms of bonding?

Answer 1

Covalent bonds

Question 2

What are all atoms of polymer joined by?

Answer 2

Strong covalent bonds

Question 3

TIP FOR DRAWING OUT POLYMER (NO NEED TO REMEMBER)

Answer 3

Instead of drawing out a whole long polymer molecule (which can contain thousands or even milions of atoms), you can draw the shortest repeating section, called the repeating unit

(CHECK CGP PAGE 117 FOR THIS)

Question 4

How do you find the molecular formula of a polymer?

Answer 4

Write down its molecular formula of the repeating unit in brackets and put an ‘n’ outside

So for polyethene the molecular formula of the polymer is (C2H4)n

Question 5

How strong are the intermolecular forces between polymer molecules?

Answer 5

The intermolecular forces between polymer molecules are larger than between simple covalent molecules, so more energy is needed to break them.This means most polymers are solid at room temperature.

Question 6

What bonds are polymers intermolecular forces weaker than?

Answer 6

Ionic or covalent bonds, so they generally have lower boiling points than ionic or giant molecular compounds

Question 7

What are polymers?

Answer 7

Long chains of repeating units

Question 8

What are giant covalent structures?

Answer 8

Macromolecules

Question 9

How are giant covalent structures bonded?

Answer 9

All atoms are bonded to each other by strong covalent bonds

Question 10

What is the melting and boiling point of giant covalent structures?

Answer 10

They have very high melting and boiling points as lots of energy is needed to break the covalent bonds between the atoms

Question 11

What do most giant covalent structures not contain?

Answer 11

They don’t contain charged particles, so they don’t conduct electricity - not even when molten (except for a few weird exceptions such as graphite)

Question 12

What materials/substances are purely made from carbon atoms only?

Answer 12

Diamond,graphite and silicon dioxide (silica)

Question 13

Structure of diamond(in terms of atoms)

Answer 13

Each carbon atom forms four covalent bonds in a very rigid giant covalent structure

Question 14

Structure of graphite(in terms of atoms)

Answer 14

Each carbon atom forms three covalent bonds to create layers of hexagons. Each carbon atom also has one delocalised (free) electron

Question 15

Structure of silicon dioxide(in terms of atoms)

Answer 15

Sometimes called silica, this is what sand is made of,Each grain of sand is one giant structure of silicon and oxygen