AL Vocabulary Flashcards Preview

AS & AL Chemistry Vocab > AL Vocabulary > Flashcards

Flashcards in AL Vocabulary Deck (31):
1

acid-base indicator

a substance that changes colour over a narrow range of pH values

2

acid dissociation constant, Ka

the equilibrium constant for a weak acid
Ka = [H+][A-] / [HA]

3

activation energy

the minimum energy that colliding particles must possess for a successful collision that results in a reaction to take place

4

active site (of an enzyme)

the 'pocket' on an enzyme surface where the substrate binds and undergoes catalytic reaction

5

acyl chloride

a reactive organic compound related to a carboxylic acid, with the OH group in the acid replaced by a Cl atom, e.g. CH3COCl

6

addition polymerisation

the reaction in which monomers containing carbon-to-carbon double bonds react together to form long-chain molecules called polymers

7

addition reaction

an organic reaction in which two reactant molecules combine to give a single product molecule

8

adsorption (in catalysis)

the first stage in heterogeneous catalysis - molecules of reactants (usually gases) form bonds with atoms on the surface of the catalyst

9

Allotrope

Different crystalline or molecular forms of the same element. Graphite and diamond are allotropes

10

Alloy

A mixture of two or more metals or a metal with a non-metal

11

Amino acid residue

An amino acid unit within a polypeptide chain

12

Amphoteric

Able to behave as both an acid and a base. Aluminium oxide is amphoteric

13

Arene

Hydrocarbon containing one or more benzene rings

14

Atomic orbitals

Regions of space outside the nucleus that can be occupied by one or, at most, two electrons. Orbitals are named s, p, d, f. They have different shapes

15

Average bond energy

A general bond energy value used for a particular bond, when exact bond energy is not required. Strength of bond is slightly different in different compounds, depending on the environment of the bond

16

Azo dye

Coloured compounds formed on the addition of phenol or another aryl compound to a solution containing a diazonium ion. They contain -N=N- group.

17

acid

a proton (hydrogen ion) donor

18

base

a proton (hydrogen ion) acceptor

19

bidentate

ligands that can form two co-ordinate bonds from each ion or molecule to the central transition metal ion

20

biofuels

renewable fuels, sourced from plant or animal materials

21

boiling point

the temperature at which the vapour pressure is equal to the atmospheric pressure

22

boltzmann distribution

a graph showing the distribution of energies of the particles in a simple at a given temperature

23

bond energy/bond enthalpy

the energy needed to break 1 mole of a particular bond in 1 mole of gaseous moleculs

24

born-haber cycle

a type of enthalpy cycle used to gaseous lattice enargy

25

bronsted-lowry theory of acids

acids are proton donors are bases are proton acceptors

26

buffer solution

a solution that minimises change in pH when moderate amounts of acid or base are added. Common forms of buffer consist of either a weak acid and its conjugate base or a weak base and its conjugate acid

27

carbocation

an alkyl group carrying a single positive change on one of its carbon atom. e.g,+CH2 CH3

28

catalyst

a substance that increases the rate of a reaction but remains chemically unchanged itself at the end of the reaction

29

cathode

the negative electrode

30

cation

a positively change ion

31

chiral centre

a carbon atom