Key Terms Paper 2

Question 1

Define catalyst

Answer 1

Substance which speeds up the ROR
by lowering its activation energy
without itself being altered or used up

Question 2

Define alkane

Answer 2

Saturated hydrocarbon containing only hydrogen and carbon atoms

Question 3

Define alkene

Answer 3

Unsaturated hydrocarbon with a C=C double bond

Question 4

Define exothermic

Answer 4

When energy is transferred to the surroundings
(Energy EXits)
More energy released in making bonds than used to break them (MEXO) - net energy decrease

Question 5

Define endothermic

Answer 5

When energy is absorbed from the surroundings
More energy needed to break bonds than released when bonds are made (BENDO) - net energy increase

Question 6

Define bitumen

Answer 6

The most viscous fraction of crude oil used to surface roads

Question 7

Define kerosene

Answer 7

A relatively light fraction of crude oil
obtained through fractional distillation
used as a fuel in aviation

Question 8

Define saturated

Answer 8

Molecule containing only single bonds
e.g. Alkanes

Question 9

Define unsaturated

Answer 9

Molecule containing at least one double bond
e.g. Alkenes

Question 10

Define allotrope

Answer 10

Different physical forms of the same element in the same physical state but with different structure and properties
e.g. Diamond and Graphite and carbon allotropes

Question 11

Define carbon allotrope

Answer 11

A different form of carbon that has the same chemical composition but different chemical properties

Question 12

Define activation energy

Answer 12

minimum amount of energy required for a chemical reaction to occur

Question 13

Define covalent bond

Answer 13

A shared pair of electrons between two non-metal atoms

Question 14

Define turbidity

Answer 14

Measure of a liquid’s transparency
e.g. when the ‘x’ is covered as adding sodium thiosulphate to HCl causes the solution to go cloudy (have a higher turbidity)

Question 15

Define polymer

Answer 15

A large molecule made up of repeating units called monomers

Question 16

Define addition polymerisation

Answer 16

Chemical reaction in which monomers with a C=C join to form a single large molecule (a polymer)
No byproducts

Question 17

Define condensation polymerisation

Answer 17

when two monomers with two functional groups (e.g. diols and dicarboxylic acids) react to form a long polymer chain, releasing small molecules like water as byproducts

Question 18

Define cracking

Answer 18

Process in which a long-chain hydrocarbon is broken down into shorter, more useful hydrocarbons - an alkane and an alkene

Question 19

Define fractional distillation

Answer 19

Process of separating different lengths of hydrocarbons found in the mixture crude oil

Question 20

Define catalytic cracking

Answer 20

Method of breaking long-chain alkanes in the presence of a (zeolite) catalyst at 550°C

Question 21

Define steam cracking

Answer 21

Method of breaking long-chain alkanes without a catalyst at over 800°C

Question 22

Define zeolite catalyst

Answer 22

The catalyst used to break down long-chain alkanes in catalytic cracking

Question 23

Define soot

Answer 23

Carbon particulates as a result of incomplete combustion

Question 24

Define ‘in excess’

Answer 24

There will always be some of that reactant left over as the other reactant is the limiting factor
More is present than is needed to react fully with other reactants

Question 25

Define precipitate

Answer 25

**An insoluble solid** which forms when two soluble substances are mixed

Question 26

Define solution

Answer 26

A mixture of two or more substances where one has dissolved into another

Question 27

Define monomer

Answer 27

A **small**, reactive **molecule** that can **bond with other identical molecules** to form a larger molecule called a **polymer** A monomer is a **small, reactive unit (molecule)** which can bond with others to form a polymer through polymerisation - in a polymer, monomers are repeating units ##Footnote## Preferably, write molecule bc it’s more accurate

Question 28

Define intermolecular forces

Answer 28

**Weak**, attractive forces between molecules ## Footnote Inter - think interfaith dialogue

Question 29

Define nanotubes

Answer 29

Very small Cylindrical fullerenes resembling graphene

Question 30

Define fullerene

Answer 30

Hollow, spherical or cylindrical carbon molecules

Question 31

Define functional group

Answer 31

A group of atoms which determines the chemical properties of a homologous series ## Footnote Functional group of alcohols -OH Functional group of carboxylic acids -COOH Functional group of esters -COO Functional group of alkenes C=C

Question 32

Define alcohol

Answer 32

An organic compound with a hydroxyl functional group (-OH) ## Footnote Organic compound - a carbon-based compound Compound - two or more different elements chemically bonded

Question 33

Define carboxylic acid

Answer 33

A carboxylic acid is an **organic compound** with a **carboxyl functional group** (**-COOH**) They are **weak acids** because their **ions only partially dissociate in water**

Question 34

Define ester

Answer 34

**Compounds** with the functional group **-COO-** formed by a **condensation reaction** between a carboxylic acid and an alcohol

Question 35

Define giant covalent structure

Answer 35

A large number of atoms joined by strong covalent bonds

Question 36

Define diamond

Answer 36

A giant covalent structure of carbon in a rigid lattice structure ## Footnote Carbon atoms form 4 bonds Not a fullerene because its not hollow

Question 37

Define graphite

Answer 37

A giant covalent structure of carbon atoms arranged in hexagons in sheets ## Footnote Carbon atoms form 3 bonds

Question 38

Define graphene

Answer 38

One layer of graphite A giant covalent structure of carbon

Question 39

Define halogen

Answer 39

A non-metal element in group 7 of the periodic table

Question 40

Define halide ion

Answer 40

A negative ion formed when a halogen gains an electron

Question 41

Define alkali metal

Answer 41

Group 1 elements

Question 42

Define noble gas

Answer 42

Inert group 0 elements

Question 43

Define hydrocarbon

Answer 43

A compound **only** made of **hydrogen** and **carbon** atoms

Question 44

Define crude oil

Answer 44

A mixture of hydrocarbons formed from the remains of ancient organisms

Question 45

Define solute

Answer 45

A substance that dissolves in a solvent to form a solution

Question 46

Define solvent

Answer 46

The liquid in which a substance (the solute) dissolves

Question 47

Define molecule

Answer 47

Two or more atoms chemically bonded ## Footnote e.g. O2 All compounds are molecules but not all molecules are compounds

Question 48

Define compound

Answer 48

Two or more different elements held together by chemical bonds ## Footnote All compounds are molecules (But not all molecules are compounds)

Question 49

Define organic compound

Answer 49

A carbon based compound ## Footnote Compound - Two or more different elements held together by chemical bonds

Question 50

Define simple molecular substance

Answer 50

**small molecules** (two or more atoms held together by **strong covalent bonds**) **forming a substance** with **low melting and boiling points** due to **weak intermolecular forces** between these molecules ## Footnote Always covalent

Question 51

Define homologous series

Answer 51

A group of **compounds** with the **same general formula** and the **same functional group** meaning they have **similar chemical properties**