Alkane Flashcards
What are saturated hydrocarbons?
Only contain single carbon-carbon bonds
What are unsaturated hydrocarbons?
Contains at least one double bond or triple bond
What is a functional group?
A group of atoms in a molecule that determines the reactivity if a molecule.
What is a homologous series?
A group of compunds that have the same functional group but a different number of CH2 groups.
How are molecules chemically reactive in a homologous series?
They have similar chemical reactions.
What are responsible for the physical properties of a substance?
The intermolecular forces.
The longer the carbon chain, the ____
its melting/boiling point…
Higher
This is because there are more electrons so higher melting point.
What is the general formula of an alkane?
CnH2n+2
What is a structural isomer?
Same molecular formula but different structural formula.
What is a chain isomer?
same functional group just a smaller carbon chain.
What is a positional isomer?
Two structural isomers that have the same type of functional groups in a different position in the compound.
What is a functional group isomer?
Same molecular formula but different type of functional group
what are the problems with CO2(g)
green house gas
What problem is there with H2O(g)?
greenhouse gas
What problem are there with CO(g)?
toxic
flammable
What problem are there with NO(g)
causes acid rain
respiratory issues
What problem are there with C(s)/soot?
smog
What problem are there with SO2(g)?
respiratory issues
causes acid rain
What problem are there with unburnt hydrocarbons
smog
how does SO2 form acid rain?
SO2 (g)+ H2O—-> H2SO3(l)
what did scientist do to reduce the amount of SO2?
at the top of factories there is a mesh coated with CaO with a large surface area.
SO2(g)+CaO(s)—->CaSO3(s)
How does NO(g) form?
in very high temperatures
N2(g)+O2(g)—>2NO(g)
forms
How does NO form acid rain?
2NO(g)+O2(g)—>2NO2(g)
4NO2(g)+O2(g)+2H2O(g)
—>4HNO3(l)
What did scientist do to reduce C(s) going into the atmosphere?
A filter is put into the car and stops it from going into the atmosphere.
What reactions occur inside a catalytic converter?
unburnt hydrocarbon + O2—> H2O(g)+CO(g)
2NO(g)+2CO(g)—>N2(g)+ 2CO2(g)
What does each fraction contain?
alkanes of similar properties
outline the process of fractional distillation.
- crude oil is heated in a furnace to make a vapour.
- the vapour passes through into the column.
3.the column has a negative temperature gradient so the fractions are separated by boiling point. - larger molecules condense near the bottom of the column.
What is the order of fraction?
Going from bottom to top:
1. Bitumen
2.lubricating oil
3.diesel oil
4.kerosene
5. Petrol
6.gases
What is cracking?
the process of taking longer chained carbons and breaking them into smaller more desirable carbon chains.
What are the two types of cracking?
Thermal and catalytic.
what are the conditions for thermal cracking?
700-1000degreess
1000KPa
What are the products formed by thermal cracking?
one alkane and one more alkenes
what are the conditions required for catalytic cracking?
525-700 degrees
100kPa
zeolite catalyst
What products are formed by catalytic cracking?
branched alkanes
aromatic compounds
cycloalkanes
what are the advantages of thermal crackling
produces alkenes which are used for plastics
what are the disadvantages of thermal cracking?
expensive due to high pressures and temperatures
what are the advantages of catalytic cracking?
the catalyst makes it a quicker and cheaper process
produces branched alkanes which can be used for car fuels.
what are the disadvantages of catalytic cracking?
can be expensive due to zeolites needing to be repaired.
