Organic Chemistry Introduction Flashcards
Define empirical formula.
Define empirical formula.
Simplest whole number ratio of atoms in a molecule
Define molecular formula.
Define molecular formula.
Gives the actual number of atoms of different elements in a molecule
Define displayed formula
Define displayed formula
Shows every atom and every bond in a molecule
Define structural formula
Define structural formula
Shows arrangement of atoms in a molecule without showing every bond
Define skeletal formula
Define skeletal formula
Drawn as lines with each vertex being a carbon atom. Carbon atoms not drawn, assumed each C atom has all unspecified bonds as C-H
Give the prefixes for: Give the prefixes for:
a) CH3 group
b) C2H5 group
c) C3H7 group
d) C4H9 group
e) Cl group
f) Br group
g) I group
Give the prefixes for:
a) CH3 group methyl-
b) C2H5 group ethyl-
c) C3H7 group propyl-
d) C4H9 group butyl-
e) Cl group chloro-
f) Br group bromo-
g) I group iodo-
www. pmt.e
What is functional group isomerism?
What is functional group isomerism?
Same atoms but a different functional group due to a different arrangement of atoms
www.pmt.educa
What is chain isomerism?
What is chain isomerism?
Hydrocarbon chain organised differently e.g. branched chains
Define stereoisomerism.
Define stereoisomerism.
When molecules have the same structural and molecular formula, but have a different arrangement of atoms in space
What is E-Z isomerism and how are the E and Z isomers decided?
What is E-Z isomerism and how are the E and Z isomers decided?
E-Z isomerism is caused by the limited rotation about C=C double bonds
If the two substituents with the highest molecular mass are on the same side of the double bond, it is the Z (zusammen) isomer
If they are on different sides, it is the E (entgegen) isomer
What is an alkane?
What is an alkane?
A saturated hydrocarbons containing C-H bonds only
Are their bonds polar? Why/why not?
Are their bonds polar? Why/why not?
Nonpolar- carbon and hydrogen have similar electronegativities
Intermolecular forces? Why?
Intermolecular forces? Why?
Only van der Waals forces of attraction - bonds are non-polar
Solubility in water? why?
Solubility in water? why?
Insoluble because hydrogen bonds in water are stronger than alkanes’ van der Waals forces of attraction
How reactive are alkanes?
How reactive are alkanes?
Very unreactive
Which reactions will alkanes undergo?
Which reactions will alkanes undergo?
Combustion and reaction with halogens
What is crude oil? How is it formed? Is it renewable? Why?
What is crude oil? How is it formed? Is it renewable? Why?
Mixture of fractions (hydrocarbons with similar boiling points and properties)
Formed at high temperatures and pressures deep below earth’s surface over millions of years → therefore non-renewable
Name the fractions from high to low boiling point.
Name the fractions from low to high boiling point.
Gases - fuel on site Gasoline/petrol/naphtha - cars Kerosene/paraffin - jet fuel, lighting Diesel oil - lorries/taxis
Lubricating oil/waxes - candles, engine oil Fuel oil - ships, power stations Tar/bitumen - roads/roofing
What is fractional distillation/how does it work?
What is fractional distillation/how does it work?
Crude oil heated until mostly vapourised
Passed into a fractionating tower that is cooler at the top than the bottom Liquid fractions are piped off at the bottom
Vapours rise up the column and - via trays and bubble caps - condense when temperature < their boiling point
Shortest chain hydrocarbons condense at the top as they have the lowest boiling points
What is fracking and how is it done?
What is fracking and how is it done?
Natural gas held within shale rock
Drill into shale, force pressurised water and sand into rock to fracture it, Collect gas
HCl and methanol added to break up shale and prevent corrosion
Pros/cons of fracking?
Pros/cons of fracking?
Advantages - gas supply for many years, reduces imported gas and electricity
Disadvantages - lots of traffic to local area, concern about amount of water used, chemical additives can pollute water supplies, can cause small earthquakes, combust CH4 → CO2 → global warming
Why are alkanes cracked?
Why are alkanes cracked?
To turn a long chain alkane, with is not very economically valuable, into a shorter chain alkane (more economically valuable as can be used as a fuel) and an alkene (more reactive, starting point for many products)
What are the conditions for thermal cracking?
What are the conditions for thermal cracking?
700-1200 K temperature Up to 7000 kPa pressure
What is the intermediate for the reaction?
What is the intermediate for the reaction?
Free radicals
What r the main products of thermal cracking
Alkenes
What are the conditions for catalytic cracking?
What are the conditions for catalytic cracking? Lower temp (720K) Lower pressure (but above atmospheric) Zeolite catalyst (SiO2 and Al2O3) with a honeycomb structure to give a large surface area
What are the main products of catalytic cracking?
What are the main products of catalytic cracking?
Cycloalkanes, aromatic hydrocarbons, branched alkanes
Write an equation for the combustion of propane
Write an equation for the combustion of propane
C3H8 + 5O2 → 3CO2 + 4H2O
What is a feul
Sumn which releases heat energy when combusted
What are the five main fuels comprising of alkanes?
What are the five main fuels comprising of alkanes?
Methane, butane, propane, petrol (about C8), paraffin (C10 - C18)
What is incomplete combustion and what products are formed in the case of alkanes?
What is incomplete combustion and what products are formed in the case of alkanes?
Combustion in a limited supply of oxygen
CO - carbon monoxide - poisonous
C - carbon - particulates - soot - global dimming
What is the environmental impact of carbon monoxide?
It is toxic/poisonous
What is the environmental impact of carbon monoxide?
It is toxic/poisonous
Which type of hydrocarbons are most likely to undergo incomplete combustion?
Longer chains
What is the environmental impact of sulfur impurities/sulfur dioxide
What is the environmental impact of sulfur impurities/ sulfur dioxide?
form sulphuric acid → acid rain
What is the environmental impact of soot (carbon)?
What is the environmental impact of soot (carbon)?
asthma, cancer, global dimming
What is the environmental impact of unburnt hydrocarbons?
What is the environmental impact of unburnt hydrocarbons?
Photochemical smog
What is the environmental impact of carbon dioxide?
What is the environmental impact of carbon dioxide?
greenhouse gas → global warming, increases global temperatures, speeds up climate change
What is the environmental impact of water vapour?
What is the environmental impact of water vapour?
greenhouse gas → global warming, increases global temperatures, speeds up climate change
What r flue gases
Gases given out by power stations