Key terms of head start

Question 1

Accuracy

Answer 1

How close measurements are to their true value

Question 2

Activation energy

Answer 2

The minimum energy required by reactants in order for a chemical reaction to occur

Question 3

Aliquot

Answer 3

The liquid from the pipette (sub-sample taken from the original sample)

Question 4

Burette

Answer 4

A graduated glass tube for delivering known volumes of a liquid, especially in titrations

Question 5

Combustion

Answer 5

A chemical reaction between substances, usually including oxygen and usually accompanied by the generation of heat and light in the form of flame.

Question 6

Concordant titres

Answer 6

Measurements that are within a defined volume of each other (0.1mL)

Question 7

Condensation reaction

Answer 7

Molecules react and link together by covalent bonding with the elimination of a small molecule e.g. water or HCl from the bond formed

Question 8

Dipole-dipole

Answer 8

Force between the positive end of a polar molecule and the negative end of a polar molecule e.g. H2O and HCl (difference in electronegativity)

Question 9

Dispersion force

Answer 9

Present between all molecules despite polarity e.g. Cl and Cl

Question 10

Electrolyte

Answer 10

Liquids that can conduct electricity

Question 11

End point

Answer 11

Point where the indicator changes colour

Question 12

Equivalence point

Answer 12

Exact mole ratio of reactants are present so acids and bases are equal in concentration and neither is in excess

Question 13

Endothermic reaction

Answer 13

Energy is absorbed from the surroundings

Question 14

Exothermic reaction

Answer 14

Energy is released to the surroundings

Question 15

Flashpoint

Answer 15

The temperature at which a particular organic compound gives off sufficient vapour to ignite in the air

Question 16

Half equation

Answer 16

Change in oxidation states in a redox reaction

Question 17

Hydrogen bond

Answer 17

Intermolecular force that is a special type of dipole-dipole force when a hydrogen atom bonds to a highly electronegative atom (NOF)

Question 18

Hydrolysis reaction

Answer 18

The chemical breakdown of a compound due to reaction with water

Question 19

Ion-dipole reaction

Answer 19

Attractive force that results from the electrostatic attraction between an ion and a neutral molecule that has a dipole

Question 20

Isomers

Answer 20

Have the same number of atoms but vary structurally

Question 21

Metabolism

Answer 21

The chemical processes that occur within a living organism in order to maintain life

Question 22

Miscible

Answer 22

Two liquids that can dissolve and form a single layer when mixed e.g. not oil and water

Question 23

Non-renewable

Answer 23

Resources that are being used at a faster rate than they can be replenished

Question 24

Oxidant

Answer 24

Electron acceptor (undergo reduction)

Question 25

Oxidation

Answer 25

An increase in oxidation number and loss of electrons

Question 26

Oxidation number

Answer 26

Used to find oxidising and reducing agents by a change in their perceived valency

Question 27

Oxidised

Answer 27

To convert an element into an oxide by combining with oxygen or removing hydrogen

Question 28

Pipette

Answer 28

A slender tube for transferring or measuring small quantities of liquid

Question 29

Precision

Answer 29

How close measured values are to each other

Question 30

Rate of reaction

Answer 30

The speed at which a chemical reaction occurs

Question 31

Reductant

Answer 31

Electron donors (undergo oxidation)

Question 32

Reduced

Answer 32

Decreasing oxygen or increasing hydrogen

Question 33

Reduction

Answer 33

A decrease in oxidation numbers or a gain of electrons

Question 34

Reliability

Answer 34

Experiment is able to produce consistent results even in varying conditions then by repeating and averaging the results gathered

Question 35

Renewable

Answer 35

Resources that are produced/replenished faster than they are used

Question 36

Saturated

Answer 36

Contain only carbon to carbon single bonds

Question 37

Sustainable

Answer 37

The ability to meet the needs of the current generation without compromising the ability of future generations to meet their own needs

Question 38

Thermochemical equation

Answer 38

A balanced stoichiometric chemical equation that includes the enthalpy change

Question 39

Unsaturated

Answer 39

Contain at least one carbon to carbon double bond

Question 40

Validity

Answer 40

Whether or not the experiment is suitable to address the aim and hypothesis of the research

Question 41

Reproducibility

Answer 41

Closeness of results from repeated experiments using the same method under different conditions

Question 42

Repeatability

Answer 42

Closeness of results obtained using the same method, materials and under the same conditions