Gases

Question 1

Biosphere

Answer 1

The part of the earth’s environment that supports life

Question 2

Carbon-oxygen cycle

Answer 2

The path taken by carbon and oxygen atoms as they react to form new compounds and move around the biosphere

Question 3

Greenhouse effect

Answer 3

A warming of the earth’s atmosphere due to the absorption of infrared radiation by gases such as carbon dioxide and water vapour

Question 4

Greenhouse gases

Answer 4

Gases which are able to absorb infrared radiation coming from the Earth’s surface, e.g. carbon dioxide and methane

Question 5

Ozone layer

Answer 5

A region in the atmosphere, 10-30 km above the earth’s surface, with a higher concentration of ozone than other regions of the atmosphere

Question 6

Nitrogen fixation

Answer 6

The conversion of nitrogen into nitrate and ammonium ions

Question 7

Nitrogen-oxygen cycle

Answer 7

The path taken by nitrogen and oxygen atoms as they react to form new compounds and move around the biosphere.

Question 8

Stratosphere

Answer 8

A region in the atmosphere beyond the troposphere where the temperature ranges from -25 C to 25 C

Question 9

Troposphere

Answer 9

A region in the inner atmosphere where the temperature ranges from 25 C to -25 C

Question 10

Ultraviolet radiation

Answer 10

A form of high-energy radiation coming from the sun

Question 11

Acid rain

Answer 11

Rainwater that has reacted with acidic emissions from industry and has a pH less than 5.5

Question 12

Acidic oxide

Answer 12

An oxide, generally of a non-metal, that either reacts with water to form an acid or reacts with a base

Question 13

Chloroflurocarbons

Answer 13

Synthetic compounds containing chlorine, fluorine and carbon atoms, e.g. CF2Cl2

Question 14

Fossil fuels

Answer 14

Coal, oil and natural gas; fuels derived from the remains of animal and plant matter

Question 15

Enhanced greenhouse effect

Answer 15

An increase in the temperature of the atmosphere due to an increased concentration of greenhouse gases such as carbon dioxide and water vapour

Question 16

Greenhouse gases

Answer 16

Gases which are able to absorb infrared radiation coming from the Earth’s surface, e.g. carbon dioxide and methane

Question 17

Global warming

Answer 17

The gradual increase of Earth’s temperature

Question 18

Haemoglobin

Answer 18

A protein in blood that transports oxygen around the body to the cells

Question 19

Halons

Answer 19

Synthetic compounds containing chlorine, bromine and carbon atoms

Question 20

Oxidised

Answer 20

When a substance has lost one or more electrons

Question 21

Ozone layer

Answer 21

A region in the stratosphere, 10-30 km above the Earth’s surface, with a higher concentration of ozone than other regions of the atmosphere

Question 22

Photochemical smog

Answer 22

Air pollution produced through the action of sunlight on oxides of nitrogen and unburnt hydrocarbons to form ozone and other pollutants

Question 23

Propellant

Answer 23

An unreactive gas that is compressed and used to disperse liquids

Question 24

Basic oxide

Answer 24

An oxide of a metal which either reacts with water to form hydroxide ions or reacts with H3O+ ions

Question 25

Catalyst

Answer 25

A substance that increases the rate of a reaction but are not consumed in that reaction

Question 26

Corrosion

Answer 26

The reaction of a metal with oxygen and other substances in its environment

Question 27

Decomposition

Answer 27

The breaking down of a compound to form two or more other compounds or elements

Question 28

Displacement

Answer 28

A process in which one substance replaces another

Question 29

Dry ice

Answer 29

Solid carbon dioxide

Question 30

Fermentation

Answer 30

The conversion of sugar solutions, in the presence of yeast, to form ethanol and carbon dioxide

Question 31

Fractional distillation

Answer 31

The separation of a mixture into different fractions, each containing a number of gases with similar boiling temperatures

Question 32

Noble gas

Answer 32

The unreactive gaseous elements of group 18 of the periodic table

Question 33

Absolute zero

Answer 33

-273 C or 0 K. Molecules and atoms have minimum kinetic energy at this temperature

Question 34

Avogadro's law

Answer 34

At the same temperature and pressure, equal volumes of all gases contain the same number of molecules

Question 35

Boyle's law

Answer 35

Pα 1/v at constant temperature

Question 36

Charles' law

Answer 36

V α T at constant temperature

Question 37

Combined gas equation

Answer 37

P1V1 / n1T1 = P2V2 / n2T2

Question 38

Elastic

Answer 38

Able to be stretched and then return to original shape when stretching force is removed

Question 39

General gas equation

Answer 39

pV=nRT

Question 40

Ideal gas

Answer 40

A gas that obeys the general gas equation at all temperatures and pressures

Question 41

Kelvin scale

Answer 41

The absolute temperature scale (K= C + 273)

Question 42

Kinetic energy

Answer 42

The energy that a particle or body has because of its motion

Question 43

Molar volume

Answer 43

The volume occupied by 1 mole of gas at a specified set of conditions. At SLC, the molar volume of gases is 24.5 L/mol

Question 44

Mole

Answer 44

The amount of substance that contains the same number of fundamental particles as there are atoms in 12 grams of Carbon 12, symbol n

Question 45

Pressure

Answer 45

The force exerted per unit area of a surface

Question 46

Partial pressure

Answer 46

The pressure exerted by one component of a mixture of gases

Question 47

Standard laboratory conditions (SLC)

Answer 47

Defined as 25C or (298 K) and 101.3 kPa pressure

Question 48

Standard temperature and pressure (STP)

Answer 48

Defined as 0C or (273 K) and 101.3 kPa pressure

Question 49

Volume

Answer 49

The amount of space that a substance requires