Definitions

Question 1

Amount of substance

Answer 1

The quantity that has moles as its units, used as a way of counting atoms

Question 2

What does anhydrous mean

Answer 2

Containing no water molecules

Question 3

Mole

Answer 3

The amount of any substance containing as many elementary particles as there are carbon atoms in exactly 12g of the carbon-12 isotope

Question 4

Avogadro Constant

Answer 4

6.02x10^23 per mole - the number of atoms per mole of carbon - 12

Question 5

Relative atomic mass

Answer 5

The weighted mean mass of an atom of an element compared with 1/12 of the mass of an atom of carbon 12

Question 6

Relative Formula Mass

Answer 6

The weighted mean mass of the formula unit of a compound compared with 1/12 of the mass of an atom of carbon-12

Question 7

Relative isotopic mass

Answer 7

The mass of an isotope compared with 1/12 of the mass of an atom of carbon-12

Question 8

Relative Molecular mass

Answer 8

The weighted mean mass of a molecule of a compound compared with 1/12 of the mass of an atom of carbon -12

Question 9

First ionisation energy

Answer 9

The energy required to remove one electron from each atom in one mole of gaseous atoms of an element to form one mole of gaseous 1+ ions

Question 10

Molar Mass

Answer 10

Ther mass per mole of a substance measured in grams per mole

Question 11

Mass number

Answer 11

The sum of the number of protons and neutrons in the nucleus

Question 12

Molecular Formula

Answer 12

A formula that shows the number and type of atoms of each element present in a molecule

Question 13

Empirical Formula

Answer 13

The simplest whole-number ratio of atoms of each element in a compound

Question 14

Hydrated

Answer 14

A crystalline compound containing water molecules

Question 15

Water of crystallisation

Answer 15

Water molecules that are bonded into a crystallise structure of a compound

Question 16

Second ionisation energy

Answer 16

The energy required to remove one electron from each ion in one mole of gaseous 1+ ions of an element to form one mole of gaseous 2+ ions

Question 17

Standard Solution

Answer 17

A solution of known concentration

Question 18

Concentration of a solution

Answer 18

The amount of solute, in moles, dissolved in each 1dm^3 of solution

Question 19

Molar gas volume

Answer 19

The volume per mole of gas molecules at a stated temperature and pressure

Question 20

How can you convert from dm^3 to m^3?

Answer 20

x10^-3

Question 21

How to convert from cm cubed to m cubed

Answer 21

X10^-6

Question 22

How to convert from kPa to Pa

Answer 22

x10^3

Question 23

How to convert from °C to K

Answer 23

+273

Question 24

Stoichiometry

Answer 24

The ratio of the amount, in moles, of each substance in a chemical reaction

Question 25

Theoretical yield

Answer 25

The yield resulting from the complete conversion of reactants into products - in other words the maximum possible amount of product

Question 26

Actual Yield

Answer 26

The amount of product obtained from a reaction

Question 27

Percentage yield

Answer 27

Actual yield ————————————— X 100 Theoretical yield of product

Question 28

Periodicity

Answer 28

A repeating trend in properties of the elements across each period of the periodic table

Question 29

Limiting reagent

Answer 29

The reactant that is not in excess, which will be used up first and stop the reaction

Question 30

Atom economy

Answer 30

A measure of how well atoms have been utilised - (sum of molar masses of desired products) /(sum of molar masses of all product) x100

Question 31

Lone pair

Answer 31

An outer shell pair of electrons that is not involved in chemical bonding

Question 32

What is a bond angle?

Answer 32

The angle between two bonds

Question 33

Dipole

Answer 33

A separation in electrical charge so that one atom of a polar covalent bond, or one end of a polar molecule, has a small positive charge and the other has a small negative charge

Question 34

Electronegativity

Answer 34

A measure of the attraction of a bonded atom for the pair of electrons in a covalent bond

Question 35

Dipole-dipole force

Answer 35

An attractive force between permanent dipoles in neighbouring polar molecules

Question 36

Polar molecule

Answer 36

A molecule with an overall dipole, having taking taken into account any dipoles across bonds and the shape of the molecule

Question 37

Polyatomic ion

Answer 37

An ion containing more than one atom

Question 38

Permanent dipole

Answer 38

A small charge difference that does not change across a bond, with positive and negative partial charges on the bonded atoms on the bonded atoms: the result of the bonded atoms having different electronegativities

Question 39

Permanent dipole-dipole interactions

Answer 39

Attractive forces between the permanent dipole in different molecules

Question 40

Dipole-dipole force

Answer 40

An attractive force between permanent dipoles in neighbouring polar molecules

Question 41

What is a binary compound?

Answer 41

A compound which contains only two elements

Question 42

What is a mass spectrum?

Answer 42

The output from a mass spectrometer that shows the different isotopes that make up an element

Question 43

What is the function of a mass spectrometer?

Answer 43

It accurately determined the mass and abundance of separate atoms or molecules, helping us to identify them