As Chemistry Unit 1 Module 1

Front 1

Isotopes

Back 1

Are atoms of the same element with different numbers of neutrons.

Front 2

Relative isotopic mass

Back 2

Is the mass of an atom of an isotope compared with one-twelfth of the mass of an atom of carbon-12.

Front 3

Relative atomic mass (Ar)

Back 3

Is the weighted mean mass of an atom of an element compared with one-twelfth of the mass of an atom of carbon-12.

Front 4

Relative molecular mass (Mr)

Back 4

Is the weighted mean mass of a molecule compared with one-twelfth of the mass of an atom of carbon-12.

Front 5

Relative formula mass

Back 5

Is the weighted mean mass of a formula unit compared with one-twelfth of the mass of an atom of carbon-12.

Front 6

Amount of substance

Back 6

1 mole. (Is the quantity whose unit is the mole)

Front 7

The Avogadro constant (NA)

Back 7

Is the number of atoms per mole of the carbon-12 isotope (6.02 x 1023 mol-1)

Front 8

A mole

Back 8

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

Front 9

Molar mass (M)

Back 9

Is the mass per mole of a substance (gmol-1)

Front 10

The empirical formula

Back 10

Is the simplest whole-number ratio of atoms of each element present in a compound.

Front 11

The molecular formula

Back 11

Is the actual number of atoms of each element in a molecule.

Front 12

Molar volume

Back 12

Is the volume per mole of a gas. (dm3 mol-1) / (24.0dm3 mol-1)

Front 13

A standard solution

Back 13

Is a solution of known concentration.

Front 14

A species

Back 14

Is any type of particle that takes part in a chemical reaction.

Front 15

Stoichiometry

Back 15

Is the molar relationship between the relative quantities of substances taking part in a reaction.

Front 16

An acid

Back 16

Is a species that is a proton donor.

Front 17

A base

Back 17

Is a species that is a proton acceptor.

Front 18

An alkali

Back 18

Is a type of base that dissolves in water forming hydroxide ions.

Front 19

A salt

Back 19

Is any chemical compound formed from an acid when a H+ ion from the acid has been replaced by a metal ions or another positive ion, such as the ammonium ion NH4+.

Front 20

A cation

Back 20

Is a positively charged ion.

Front 21

An anion

Back 21

Is a negatively charged ion.

Front 22

Hydrated

Back 22

Refers to a crystalline compound containing water molecules.

Front 23

Anhydrous

Back 23

Refers to a substance that contains no water molecules.

Front 24

Water of crystallisation

Back 24

Refers to water molecules that form an essential part of the crystalline structure of a compound.

Front 25

An oxidation number

Back 25

Is a measure of the number of electrons that an atom uses to bond with atoms of another element.

Front 26

Oxidation

Back 26

Is loss of electrons or an increase in oxidation number.

Front 27

Reduction

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Is gain of electrons or a decrease in oxidation number.

Front 28

A redox reaction

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Is a reaction in which both reduction an oxidation take place.

Front 29

A reducing agent

Back 29

Is a reagent that reduces another species.

Front 30

An oxidising agent

Back 30

Is a reagent that oxidises another species.