Basics/definitions

Question 1

Describe covalent bonding

Answer 1

Atoms share a pair of electrons in their outer shells. As a result the outer shell of both atoms is filled and and a stable compound called a molecule is produced.

Question 2

Describe ionic bonding

Answer 2

One atom gains electrons and the other loses electrons to form ions. Ions with opposite charges attract one another. This creates electrostatic attraction which forms ionic bonds.

Question 3

Describe hydrogen bonding

Answer 3

• Molecules that are polarised have an uneven distribution of charge as electrons tend to spend more time in certain positions.
• The negative region of one polarised molecule and the positively charged region of another attract each other and a weak electrostatic hydrogen bond is formed.

Question 4

Define polymer

Answer 4

A substance or material consisting of very large macromolecules that are composed of many repeating subunits called monomers.

Question 5

Define monomer

Answer 5

A small molecule/subunit that can react with other monomer molecules to form a large polymer chain or 3-dimensional network in a process called polymerisation.

Question 6

Define polymerisation

Answer 6

A chemical reaction where monomer molecules join together to form polymer chains or three-dimensional networks.

Question 7

Define condensation reaction

Answer 7

Any reaction that produces water as a by-product of two molecules combining to form a larger molecule.

Question 8

Define hydrolysis

Answer 8

Any reaction in which a molecule of water breaks one or more covalent bonds.

Question 9

Define monosachharide

Answer 9

A single saccharide/sugar monomer. They are not decomposable to simple sugars by hydrolysis as they are already in their simplest form.

Question 10

Define disaccharide

Answer 10

Any substance composed of two molecules of simple sugars (monosaccharides) linked to each other.

Question 11

Define polysaccharide

Answer 11

Polysaccharides are polymers that consist of many monosaccharides joined by glycosidic bonds in a condensation reaction.

Question 12

Define reducing sugar

Answer 12

A reducing sugar is a sugar that can donate electrons to reduce another chemical.

Question 13

Define glycosidic bond

Answer 13

The bond that forms between a carbohydrate molecule and another molecule that may or may not be a carbohydrate.

Question 14

Define mole

Answer 14

A mole of a substance contains the same number of particles as there are in 12g of carbon-12 atoms (6.022 x 10^23 atoms in 12g of carbon twelve)

Question 15

Define molar solution

Answer 15

A solution that contains one mole of solute in each litre of solution.