organic chemistry Flashcards
organic
compounds containing carbon as the main component (also H,O)
hydro carbons
compounds containing carbon and hydrogen only
homoglous series
groups of chemicals with the same general formula, a pattern of physical properties, similar properties.
what is an alkane
it is a hydrocarbon containing only single bonds
what is the general formula for an alkane
CnH2n+2
how do you know how many carbons there are in an alkane
the root of the name tells us
no. of carbons in alkanes:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
root in alkane name
meth
eth
prop
but
pent
hex
hept
oct
non
dec
physical properties of an alkane
covalent discrete
- are oils
- the larger the molecules the more IMFs so the higher the tempreture
- viscosity, larger molecules are more viscous
-volatility, smaller the molecules the more volatile
- colour: small= colourless, medium=yellow, large=black
what is viscosity
the resistance to flow
what is volatility
the ease of turning into a gas
empirical formula
the lowest ratio of elements within a compound
molecular
the number of atoms of each element in a molecule
structural
the atoms connected to each C atom, listed in order
displayed
the exact bonds connecting each atom in a molecule
general
the mathematical equation that can be used to determine the number of one element compared to another
isomers
compounds with the same molecular formula but a different arrangement of atoms (different structural formula) and different physical properties
what is the root in isomers
the longest chain of carbons
measuring enthalpy change of HCL + Mg
- measure 10cm3 of HCL into a calorimeter
- measure 0.30g - 0.50g of Mg
- record initial temp. of acid
- add Mg to HCL and start timing
- record temp. every 15s until it has been decreasing for 45s
what 3 types of reactions do alkanes undergo
substitution
decomposition
combustion
why are alkanes generally unreactive
they contain only strong covalent bonds (saturated). energy need to be provided to cause a reaction (Ea)
how can energy be provided as for alkanes reactions
heat
light
electricity
substitution with halogens
requires UV light
alkane + halogen —-> haloalkane + hydrogen halide
complete combustion reaction
alkane + oxygen —-> carbon dioxide + water
incomplete combustion reaction
alkane + oxygen —> carbon monoxide + water
decomposition (cracking)
heat - 300c
catalyst - Al2O3
SiO2
C16H34 —-> C9H20 + C7H14
general formula for an alkene
CnH2n
alkene
hydrocarbons containing atleast one C=C
Physical properties of an alkene
same as alkane
only the mpt/bpt is lower because they have fewer IMFs
chemical properties of an alkene
bonding a is strong whereas bonding b is weak in a double bond. this causes the bonding b to break easily allowing addition reactions to take place.
what is polymerisation
is a reaction involving alkenes
addition reaction
ethene —> polyethene
product does not have any c=c
physical properties of polymers
low mpt.
discrete covalent
do not conduct
insoluble in water
soluble in oil
chemical properties of polymers
unreactive (saturated) except for substitution or decomposition
method 1 of manufacturing ethanol
direct hydration of ethene
ethene + water —> ethanol
addition/hydration reaction
what is ethanol used for
disinfectant
as a solvent
advantages of method 1 of manufacturing ethanol
continuous process (continues to the product)
makes the pure product, no separation required
disadvantages of method 1 of manufacturing ethanol
high energy demand
non-renewable
ethene needs manufacturing
expensive
method 2 for manufacturing of ethanol
fermentation of sugars
sugar —(yeast)—>ethanol + CO2
we use fruits for the sugar
advantages for method 2 for manufacturing of ethanol
low energy required
can drink, because it has fermented sugars in it (not pure, flavoured ethanol
renewable
disadvantages method 2 for manufacturing of ethanol
batch process (opposite of continuous)
not pure ethanol, if it is above 15% then it kills the yeast (distillation can be used to increase the concentration)
what is crude oil
is a mixture of alkanes which formed from the remains of sea creatures which have reacted to form organic compounds
it is a mixture of 1000s of miscible substance all with different boiling points
laboratory separation
fractional distillation
heat in intervals of 40 degrees
otherwise it takes to long to separate them all
this separates them into mixtures with similar bpt.
what does R represent in a compound
any chemical
what is a reflux
to oxidide an alcohol you need to heat it up using a reflux. this stops the alcohol evaporation. this is so it has time to react
what are polymers
long chain of 1000s of small alkene molecules joined together
often used as plastic
how do alkenes react
by breaking the weakest bond in the double bond
how do you dispose plastic
in a landfill
of by burning
but best is to recycle
what makes alcohols different from alkanes
contain OH
how do we make alcohols
alkene + water
what does the capital R represent in a displayed formula
any chemical
how are esters formed
by reacting alcohols with carboxylic acids
reaction is called condensation
two molecules are made and one water molecule is removed
how to name esters
name of alcohol but prefix (yle) + name of acid but with suffix oate
how can u increase esterification
using a catalyst= concentrated H2SO4
increase the temp(70)
use reflux for temp
how do you make polyesters
dicarboxylic acid + dialcohol
(diol) (dioic)
how are condensation polymers formed
from two types of monomers
