defenitions

Question 1

Empirical Formula

Answer 1

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

Question 2

Functional Group

Answer 2

an atom or group of atoms present in a molecule that is responsible for its chemical characteristic properties

Question 3

General Formula

Answer 3

the simplest algebraic formula of a member of a homologous series

Question 4

Skeletal Formula

Answer 4

simplified organic formula, with the hydrogens removed, leaving just the carbon skeleton

Question 5

Structural Formula

Answer 5

minimal detail that shows the arrangement of atoms in a molecule

Question 6

Saturated

Answer 6

only contains single bonds so no more atoms can be added

Question 7

Unsaturated

Answer 7

contains at least one carbon-carbon double bond so more atoms can be added

Question 8

Mechanism

Answer 8

sequence of steps showing the path an electron takes

Question 9

Initiation

Answer 9

the first step in radical substitution, free radicals are produced by the presence of UV light

Question 10

Propagation

Answer 10

two repeated steps building up the products of a chain reaction

Question 11

Radical Substitution

Answer 11

type of reaction where a radical replaces an atom or group of atoms

Question 12

Termination

Answer 12

the end step in which radicals combine to form a molecule

Question 13

Homolytic Fission

Answer 13

the breaking of a bond in which one electron goes to each atom

Question 14

Heterolytic Fission

Answer 14

breaking of a bond in which all electrons go to one atom

Question 15

What is an ionic bond?

Answer 15

an ionic bonds is the electrostatic attraction between positive and negative ions.

Question 16

What is a covalent bond?

Answer 16

strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms.

Question 17

What is a dative (co-ordinate) covalent bond?

Answer 17

a covalent bond in which both electrons come from the same atom.

Question 18

What is the octet rule?

Answer 18

All atoms want to have a full outer shell and they lose or gain electrons in order to have the same electronic configuration of a noble gas.

Question 19

What are isotopes?

Answer 19

atoms of the same element with a different number of neutrons and different masses

Question 20

What is the relative isotopic mass?

Answer 20

the mass of an atom of an isotope of an element compared to one twelfth of carbon twelve which is exactly 12.

Question 21

What is the relative atomic mass?

Answer 21

the weighted mean mass of an atom of an element compared to one twelfth of carbon 12 which is exactly 12.

Question 22

Define anhydrous.

Answer 22

a substance that doesn’t contain water molecules

Question 23

Define hydrous

Answer 23

a substance that contains water molecules.

Question 24

What is the molecular formula?

Answer 24

the number and type of atoms of each element in a molecule.

Question 25

Define water of crystallisation.

Answer 25

if a solid material has been made form an aqueous solution then the product will frequently contain water.

Question 26

Acid

Answer 26

a proton donor

Question 27

Base

Answer 27

a proton acceptor

Question 28

alkali

Answer 28

a chemical that is soluble in water and releases hydroxide ions (a soluble base)

Question 29

electronegativity

Answer 29

a measure of the tendency of an atom to attract a bonding pair of electrons in a covalent bond

Question 30

enthalpy

Answer 30

the energy required to break a bond between two atoms

Question 31

lone pair

Answer 31

a pair of electrons not used within a covalent bond and give a concentrated region of negative charge.

Question 32

homologous series

Answer 32

a series of organic compounds that have the same functional group with successive members differing by CH2

Question 33

structural isomerism

Answer 33

same molecular formula but different structural formula

Question 34

stereoisomerism

Answer 34

same molecular formula but atoms occupy different positions in space