Energy Talbot vocabulary

Question 1

Embodied energy

Answer 1

the energy used during the entire life cycle of a product, including its manufacture, transportation, and disposal, as well as the inherent energy captured within the product itself

Question 2

fractional distillation

Answer 2

This process of separating out the oil by boiling point

Question 3

fractionating column

Answer 3

vessel in which the vapor is injected

The vapours rise up the column. As they get further from the heat source at the base of the column, the temperature falls. Gradually, each fraction condenses out of the vapour mixture. Heavy points condense first, close to the bottom of the column. As the column is ascended, successively lighter, shorter chain fractions condense. At the top of the column some very short-chain molecules are still in the vapour phase and are collected as refinery gas.

Question 4

octane number

Answer 4

• The measure of resistance to pre-ignition
• A value used to indicate the resistance of a motor fuel to knock, based on a scale on which isooctane is 100 (minimal knock) and heptane is 0 (bad knock)

Question 5

Zeolites

Answer 5

• -> natural or synthetic hydrated aluminosilicate with an open three-dimensional structure, in which water molecules are held in cavities in the lattice
• naturally occurring minerals containing aluminium, silicon and oxygen, are also very good catalysts for this process as their crystal structures contain an extensive network which offers the hydrocarbons a large surface area for reaction
• The term zeolite is derived from the Greek words zeo, meaning to boil, and lithos, meaning stone. Zeolites release large amounts of steam when heated.
• Major uses are in catalytic cracking, ion-exchange (water softening and purification) and the separation and removal of gases and solvents.

Question 6

reforming

Answer 6

• -> cyclization of straight-chain hydrocarbons from

crude oil by heating under pressure with a catalyst

Question 7

Izomerization

Answer 7

• chemical process carried out in a refinery that involves a rearrangement of atoms and bonds within a molecule, without changing the molecular formula
• from straight chains -> branched chains, which are used as fuel additives

Question 8

cyclization

Answer 8

formation of a cyclic compound from an open- chain compound

Question 9

aromatization

Answer 9

the process by which a compound forms an

aromatic ring

Question 10

• chlorophyll

Answer 10

green pigment found in plants involved in absorbing light for photosynthesis; a magnesium-based porphyrin

Question 11

pigment

Answer 11

substance that has a colour resulting from selective colour absorption

Question 12

Porphyrins

Answer 12

molecules featuring four pyrrole groups joined together by alternating carbon–carbon single and double bonds. Chlorophylls are examples of porphyrins

Question 13

Pyrrole

Answer 13

a five-membered ring containing four carbon atoms and one nitrogen atom. Pyrrole itself (C4H4NH) is a colourless, volatile liquid. Many naturally occurring larger molecules contain pyrrole rings

Question 14

tetrapyrroles

Answer 14

natural pigments containing four pyrrole

rings joined by one-carbon units linking position 2 of

one pyrrole ring to position 5 of the next

Question 15

zymase

Answer 15

• -> a mixture of enzymes found in yeast involved in fermentation (a form of anaerobic respiration)
• Fermentation is carried out by single-celled fungi called yeasts, which use an enzyme called zymase to convert glucose molecules into ethanol molecules, with production of carbon dioxide.

Question 16

lipids

Answer 16

group of organic compounds that contain carbon, hydrogen and oxygen; includes fats, oils, waxes, sterols, and triglycerides, which are insoluble in water but soluble in non-polar organic solvents, for example, ethanol (alcohol)

Question 17

fatty acid

Answer 17

a group of long monobasic acids, found in animal and vegetable fats and oils, having the general formula CnH2n+1COOH and containing an even number of carbon atoms

Question 18

transesterification

Answer 18

animal and plant fats and oils (made of triglycerides which are esters of free fatty acids with glycerol) and an alcohol (methanol or ethanol) are converted into ethyl esters and glycerol with the help of a base catalyst, usually sodium hydroxide

Question 19

loss of biodiversity

Answer 19

• a term describing the variety of life present in a particular ecosystem. ‘Loss of biodiversity’ usually describes the way in which human impact on the ecosystem affects the natural interdependence of species, leading to many organisms being displaced or dying out
  *

Question 20

peer-reviewed journal

Answer 20

a publication in which new scientific research is published. The editorial process involves each article being checked and reviewed by other experts in the specific fields involved

Question 21

Anode

Answer 21

where oxidation (the loss of electrons) occurs during an electrochemical process; in an electrolytic cell the anode is the positive electrode

Question 22

Cathode

Answer 22

where reduction (the gain of electrons) occurs during an electrochemical process; in an electrolytic cell the cathode is the negative electrode

Question 23

battery

Answer 23

• -> a group of voltaic cells connected together in series or in parallel
• The word battery has come to mean any portable device which offers a self- contained source of electricity.

There are three main types of cells or batteries: primary cells, secondary cells, and fuel cells.

Question 24

Primary cell

Answer 24

Disposable batteries used for household items such as torches, clocks and toys are primary cells. A primary cell contains a chemical mixture that uses an electrochemical reaction to generate an EMF when connected in a circuit When the chemicals have ‘run out’ the battery is exhausted and is thrown away. Such batteries are referred to as dry cells because they use an almost dry paste, rather than a liquid, as the electrolyte. This lowers the chance of toxic chemicals leaking from the battery.

Question 25

dry cell

Answer 25

* also called primary cells * they use an **almost dry paste**, rather than a liquid, as the electrolyte. This lowers the chance of toxic chemicals leaking from the battery.

Question 26

Secondary cells

Answer 26

Secondary cells are more commonly known as rechargeable batteries. They differ from primary cells in that once they are exhausted, a current can be passed through them which reverses the chemical reaction and returns the chemical mixture to its initial state. Secondary cells can be used many times and can be thought of as a way of storing electricity, rather than simply generating it. Three common types of secondary cells are the lead-acid cell, the nickel–cadmium celland the lithium-ion cell. These have different strengths and weaknesses and find different applications.

Question 27

lead-acid cell

Answer 27

* a series of secondary (rechargeable) cells in which the anode is lead, the cathode is lead coated with lead(iv) oxide and the electrolyte is moderately concentrated sulfuric acid * CAR BATTERIES

Question 28

nickel–cadmium cell

Answer 28

cell a secondary (rechargeable) cell consisting of a cadmium anode and a nickel(iii) hydroxide cathode, combined with a potassium hydroxide electrolyte. The cell reaction involves the oxidation of cadmium to cadmium(ii) and the reduction of nickel(iii) to nickel(ii)

Question 29

lithium-ion cell

Answer 29

a secondary (rechargeable) cell in which lithium ions are intercalated in a graphite lattice. The cell reaction involves the migration of lithium ions out of the graphite electrode while their electrons enter the external circuit

Question 30

intercalated

Answer 30

the term intercalation denotes a process in which a molecule or an ion (guest) is placed into a host lattice. The structure of the host remains unchanged or is only slightly altered in the guest–host complex that is in the intercalation compound (intercalate)

Question 31

Doping

Answer 31

incorporation of impurities within the crystal lattice of silicon so as to increase its conductivity