Other Helpful Definitions

Question 1

What is the definition of alcohols?

Answer 1

Carbon compounds whcich contain the hydroxyl functional group, -OH.

Question 2

What is the definition of aldehydes?

Answer 2

Carbon compounds which contain the -CHO functional group. They are formed by oxidation of primary alcohols and they oxidise to produce carboxylic acids.

Question 3

What is the definition of alkanals?

Answer 3

A homologous series of aldehydes, general formula Cn H2n O.

Question 4

What is the definition of alknoic acid?

Answer 4

A homologous series of carboxylic acids, general formula Cn H2n O2. The first memeber is methanoic acid, HCOOH.

Question 5

What is the definition of alkanones?

Answer 5

A homologous series of ketones, general formula Cn H2n O. The first memeber is propanone, Ch3 COCH3.

Question 6

What is the definition of an amide link?

Answer 6

Group of atoms formed by condensation polymerisation of amino acids in the formation of protein chains. The amide link is -CO-NH-.

Question 7

What is the definition of carbonyl group?

Answer 7

The functional group present in ketones, C=O. Also found in aldehydes as functional group -CHO as well as carboxylic acids functional group, -COOH.

Question 8

What is the definition of Carboxyl group?

Answer 8

The functional group in carboxylic acids, -COOH. The name derives from the fact that the carboxyl group contains a carbonyl and hydroxyl group.

Question 9

What is the definition of catalyst poisoning?

Answer 9

This occurs when a substance forms strong bonds with the surface of a catalyst thus reducing its efficency.

Question 10

What is the definition of a concentration?

Answer 10

The amount of solute dissolved in a given volume of solution . The usual units are moles per litre (mol/L).

Question 11

What is the definition of displacement?

Answer 11

A redox reaction where a metal high in the electrochemical series reacts with a compound of a metal lower in the electrochemical series.

Question 12

What is the definition of enthalpy change?

Answer 12

The difference in heat energy between reactants and products in a reaction.

Question 13

What is the definition of an enzyme?

Answer 13

A globular protein which is able to catalyse a specific reaction.

Question 14

What is the definition of esters?

Answer 14

Carbon compounds formed when alcohols react with carboxylic acids by condensation.

Question 15

What is the definition of fats?

Answer 15

Esters formed from one molecule of glycerol and three molecules of long chain carboxylic acids. The compounds have melting points highe enough to be solid at room temperature.

Question 16

What is the definition of fatty acids?

Answer 16

Carboxylic acids formed from the hydrolysis of fats and oils.

Question 17

What is the definition of glycerol?

Answer 17

Propan - 1,2,3 - triol. formed from the hydrolysis of fats and oils.

Question 18

What is the definition of hydrogen bonds?

Answer 18

Intermolecular forces of attraction. The molecules must contain highly polar bonds in which hydrogen atoms are linked to every electronegative nitrogen, oxygen or fluporine atoms. The hydrogen atoms are then left with a positive charge and are attracted to the electronegative atoms of other molecules. They atre a specific, stronger type of permanent dipole - permanent diplole interaction.

Question 19

What is the definition of hydrophillic?

Answer 19

A term used to describe molecules, or parts of a molecule, which are attracted to water. For example, the -OH in alcohols is hydrophillic.

Question 20

What is the definotion of hydrophobic?

Answer 20

A term used to describe molecules, or parts of a molecule, which repel water and will not bond to water. For example the long hydrocarbon chain in fats and oils are hydrophobic.

Question 21

What is the definition of Hydroxyl group?

Answer 21

The -OH group. It is found in alcohols.

Question 22

What is the definition of an indicator?

Answer 22

A chemical dye added to a titration to detect the end point.

Question 23

What is the definition of intermolecular bonds?

Answer 23

Bonds between molecules, such as London dispersion forces, permanent dipole - permanent dipole interactions and hydrogen bonds. They are much weaker than intramolecular bonds.

Question 24

What is the definition of intramolecular bonds?

Answer 24

Bonds within molecules, such as covalent and polar covalent bonds.

Question 25

What is the definition of an ion electron equation?

Answer 25

An equation that shows either the loss of electrons or the gain of electrons.

Question 26

What is the definition of isomers?

Answer 26

Compounds which have the same molecular formula but different structural formula.

Question 27

What is the definition of isotopes?

Answer 27

Atoms of the same element which have different number of neutrons. They have he same atomic number but different mass number.

Question 28

What is the definition of London dispersion forces?

Answer 28

The weak forces of attraction between all atoms and molecules, caused by temporary dipoles.

Question 29

What is the definition of miscibility?

Answer 29

The ability of liquids to mix perfectly together. In contrast, immiscible liquids form clearly defined layers with He denser liquid forming the lower layer.

Question 30

What is the definition of monatomic?

Answer 30

A term used to describe the noble gases since they are composed of individual atoms which do not bond to each other. They are held together by London dispersion forces in the liquid and solid state.

Question 31

What is the definition of permanent dipole - permanent dipole attractions?

Answer 31

The attraction between molecules which possess a permanent dipole because of the presence of polar bonds.

Question 32

What is the definition of polar covalent bonds?

Answer 32

Bonds formed between non-metallic atoms by sharing a pair of electrons. If the atoms have considerably different electronegativities, the electrons are not shared equally, the more electronegative atom becoming slightly negative in comparison with the other atom. As a result the bond is ‘polar’, for example H+ - Cl-.

Question 33

What is the definition of retention time?

Answer 33

He lengths time it takes a substance to reach the detector, in a chromatography experiment, after being injected into the chromatography column.

Question 34

What is the definition of soaps?

Answer 34

Sals of fatty acids e.g. sodium stearate. Soaps have an ionic head that is water soluble and a covalent tail which is soluble in oil.

Question 35

What is the definition of a spectator ion?

Answer 35

An ion which is present in a reaction mixture but does not take part in the reaction.

Question 36

What is the definition of a standard solution?

Answer 36

A solution of known concentration.

Question 37

What is the definition of temporary dipoles?

Answer 37

Formed in all atoms where an excess of electrons is formed at one part of the atom. Temporary dipoles are the basis for London dispersion forces.

Question 38

What is the definition of triglyceride?

Answer 38

The molecules found in fats and oils. They are formed from one glycerol molecule joining to three fatty acid molecules.

Question 39

What is the definition of viscosity?

Answer 39

A description of how thick a liquid is, for example, engine oil is thicker than petrol.

Question 40

What is the definition of a variable?

Answer 40

Something that can be changed in a chemical reaction such as temperature, particle size, concentration, etc.