organic chem Flashcards
use of paraffin oil
fuel for heating and cooking and for aircraft
general formula of alcohol
CnH2n+1OH
use of naphtha
feedstock for chemical industry
general formula of alkane
CnH2n+2
general formula of carboxylic acid
CnH2n+1COOH
define homologous series
a family of organic compounds with a general formula, having similar chemical properties and showing a gradation in physical properties
does boiling point increase/decrease down the series?
increase
use of diesel oil
fuel for diesel engines
how many carbon in prop
3
use of petrol
fuel in cars
use of lubricating oil
lubricants, making waxes and polishes
physical state of alkane and alkene
gas
use of petroluem
fuel for cooking
how many carbon in eth
2
use of bitumen
making road surfaces
does density increase/decrease down the series?
increase
does flammability increase/decrease down the series?
decrease
how many carbon in meth
1
what test is used to differentiate alkane and alkene?
bubble the gas through aqueous bromine
what colour change is observed when aqueous bromine is added to an alkene
aqueous bromine changes from reddish brown to colourless
what colour change is observed when aqueous bromine is added to an alkane
aqueous bromine remains reddish brown
does viscosity increase/decrease down the series?
increase
general formula of alkene
CnH2n
what is a functional group?
an atom or group of atoms that gives a molecule its characteristic properties
what is the functional group of alkane
no functional group
what is the functional group of alkene
carbon carbon double bond (- c=c -)
what is the functional group of alcohol
hydroxyl group (O-H)
what is the functional group of carboxylic acid
carboxyl group
O
II
—C —O—H
are alkanes saturated or unsaturated
saturated
are alkenes saturated or unsaturated
unsaturated
products formed when alkanes and alkenes burn completely in oxygen (complete combustion)
carbon dioxide and water
products formed when alkanes and alkenes burn in insufficient oxygen
soot and carbon monoxide
define substitution reaction
a hydrogen atom in an alkane is replaced by a halogen atom
define addition reaction
a reaction in which an UNSATURATED organic compound combines with another substance to form a SINGLE new compound
what kind of reaction is (methane + chlorine) ?
substitution reaction
products formed when (methane + chlorine )
chloromethane and hydrogen chloride
conditions needed for substitution reaction
sunlight/ultraviolet light
ethene + hydrogen is what kind of reaction
addition reaction with hydrogen (hydrogenation)
coverts unsaturated to saturated compound
products formed when ethene + hydrogen
ethane
define monomer
small molecules of alkene
define polymer
long chain molecule formed when alkene molecules join together
conditions needed for addition polymerisation of alkenes
-high temperature (600 °C)
-high pressure
-presence of catalyst
advantages of plastics
there are 5
- easily molded into different shapes
- waterproof
-durable
-corrosion resistant
-complete combustion of plastic produce CO2 + H20, hence no solid residue is formed minimising waste produced
disadvantages of plastics
there are 3
-flammable
-produces poisonous gas (eg. CO) when burned hence contributing to air pollution
-non biodegradable (have to dispose in landfills which takes up space and causes land pollution)
can polymers conduct electricity? why or why not?
polymers CANNOT conduct electricity because it is a covalent molecule and has NO IONS to carry electric current
define cracking
breaking down of long chain hydrocarbons into smaller molecules
describe process and conditions needed for cracking of petroleum
- pass the petroleum fraction containing long chain alkanes over a heated catalyst at about 600 °C
- catalysts are aluminium oxide and silicon dioxide
importance of cracking
there are 3
- to produce short chain alkenes such as ethene and propene used for making ethanol and plastics
- to produce hydrogen
- to produce petrol used as fuel for cars
why can alkenes be polymerized?
alkene contains c=c double bonds that can be broken and more atoms can be added to it
physical state of alcohol and carboxylic acid
liquid
what temperature is the mixture kept at during fermentation of glucose?
37 °C
why must the mixture be kept at 37 °C during fermentation of glucose?
beyond 37 °C -> enzyme will denature
below 37 °C-> fermentation will slow down
conditions for fermentation of glucose
- catalyst: yeast
- temp at 37 °C
-absence of oxygen
conditions needed for oxidation of ethanol
warm the mixture of ethanol + acidified potassium manganate (VII)
