organic chemistry 1

Question 1

what are the fossil fuels

Answer 1

coal, natural gas and petroleum

Question 2

what is the main constituent of natural gas

Answer 2

methane

Question 3

what are hydrocarbons

Answer 3

compounds only containg hydrogen and carbon

Question 4

what is petroleum

Answer 4

a mixture of hydrocarbons

Question 5

how is petroleum seperated into useful fractions

Answer 5

through fractional distillation

Question 6

what are the changing characteristics from the bottom to the top of the fractionating column

Answer 6

decreasing chain length, higher volatility, lower boiling points, lower viscosity

Question 7

what is refinery gas used for

Answer 7

gas used in heating and cooking

Question 8

what is gasoline/petrol used for

Answer 8

fuel used in cars

Question 9

what is naptha used for

Answer 9

chemical feedstock

Question 10

what is kerosene/paraffin used for

Answer 10

jet fuel

Question 11

what is diesel oil/gas oil used for

Answer 11

fuel in diesel engines

Question 12

what is fuel oil used for

Answer 12

ships and home heating systems

Question 13

what is lubricating oil used for

Answer 13

lubricants, waxes and polishes

Question 14

what is bitumen used for

Answer 14

for making roads

Question 15

what is the order of products in the fractional distillation column bottom to top

Answer 15

bitumen, fuel oil, lubricating oil, diesel, kerosene, naphtha, petrol, refinery gas

Question 16

what is a homolegues series

Answer 16

family of similiar compounds which have similiar chemical properties and have the same functional group, same general formula, trend in physical properties, differ from one member to teh next by a CH2 unit

Question 17

what is the general formula of alkanes

Answer 17

Cn H2n+2

Question 18

what is the general formula of alkenes

Answer 18

Cn H2n

Question 19

what is a functional group

Answer 19

an atom or group of atoms that determine the chemical properties of a homologous series

Question 20

structural formula

Answer 20

an ambiguous description of the way the atoms in a molecule are arranged

Question 21

what is a saturated compound

Answer 21

has molecules in which all carbon carbon bonds are single bonds (alkanes)

Question 22

what is an unsaturated compound

Answer 22

has molecules which have at least one carbon carbon double bond (alkenesO

Question 23

what are fossil fuels

Answer 23

non renewable resources that when burned produce energy

Question 24

name the first 5 beginings of hydrocarbons

Answer 24

meth
eth
prop
but
pent

Question 25

what is isomerism

Answer 25

whem molecules have the same molecular formula but different displayed formula

Question 26

how can you distinguish between alkenes and alkanes

Answer 26

add browmine water, if it is an alkene goes from orange to colourless, else remains orange

Question 27

what happens when an alkane react with halogen

Answer 27

- only reacts with presence of UV light, (photochemical reaction) because it provides activation energy needed -one of the hydrogens of the alkane is substituted by the halogen, and in addition produces another product of only a hydrogen and the halogen used eg: H-Br -called substituion

Question 28

what happens when an alkene react with halogen

Answer 28

-no UV light needed -only has one product, both halogen atoms join onto hydrocarbon -called adition

Question 29

what is the bonding in alkanes + properties

Answer 29

single covalent and are saturated hydrocarbons generally unreactive except on terms of combustion and substiution with chlorine

Question 30

what is the bonding in alkenes

Answer 30

include a double carbon-carbon covalent bond and are unstaturated hydrocarbons

Question 31

describe properties of alkenes

Answer 31

react with bromineor aqueos bromine react with hydrogen in presence of nickel catalyst react with steam in presence of an acid catalyst in general more reactive than alkanes

Question 32

how are alkenes and hydrogen manufactured

Answer 32

by the cracking of larger alkane molecules using high temp and a catalyst

Question 33

what is combustion

Answer 33

scientific word for burning in presence of oxygen and light energy is released during it

Question 34

give the formula for complete combustion

Answer 34

hydrocarbon + oxygen -> carbon dioxide + water (both carbon and hydrogen are oxidised)

Question 35

what is incomplete combustion

Answer 35

combustion in the shortage of oxygen, instead of producing just carbon dioxide and water it produces carbon monoxide and/ or carbon (soot) also releases less energy

Question 36

what is carbon monoxide

Answer 36

a colourless and odourless gas, it is poisonous and binds irreversibly with haemoglobin in your blood reducing ability of it to carry oxygen.

Question 37

what is cracking

Answer 37

the process that splits long chain alkanes into shorter chain alkanes and lakenes useful becaus elong chain alkanes can be turned into short chain alkanes/alkenes that can be used for fuels or plastics

Question 38

what are the conditions for cracking to happen

Answer 38

very high temperature and aluminium oxide or ceramic catalyst