Organic Chemistry Flashcards
Mnemonic for the different fractions of distilled petroleum
Real Great & Noble Kings Don’t Forget Ladies Birthdays
Refinery gas
Gasoline(petrol)
Kerosene Gas
Disel Oil
Fuel oil,Lubricating oil
Bitumen
Sources of Hydrocarbons
Natural gas and petroleum
Hydrocarbons
Organic Compunds composed of carbon and hydrogen atoms only
Petroleum
a complex mixture of alkanes and ringed hydrocarbons
Natural Gas
a misture of methane with small amounts of ethane propane and butane
two types of cracking are:
-Thermal cracking -Catalytic cracking
importance of cracking hydrocarbons
the larger molecules produced duringg fractionanl distillation pf petroleum can be broken downinto smaller more useful hydrocarbons
Difference between thermal and catalytic cracking
Thermal cracking uses temperatures of about 750 deg C and pressures of about 70atm. Catalytic cracking uses lower temperatures, about 500 degC and much lower pressures in the presence of a catalyst
the 4 homologus groups in organic chemistry
alkanes alkenes alcohols(or Alkanols) Carboxylic acids or alkanoic acids
The functional group in alkanoic acids
COOH(carboxyl)
The functional group in the alkanols
OH(hydroxyl group)
The functional grouo of Alkene
aCarbon to Carbon Double Bond
Generla Formula
Alkane
Alkene
Alchol
Carboxyl
CnH2n+2
CnH2n
CnH2n+1OH
CnH2n+1COOH
Characteries of a Homologus Series
All members of the series have the same functional group
All member can be represented by the sme generla formula
Each memebr of the sries differs by a CH2 group
All members of a series posses similar cgemical properties
what is a structural ismer
Structural Isomers are compunds which have the same molecular formula but different structural formual
what is structural isomerism
Structual isomerism is the occurence of two or more organic compunds with the same molecular formula but duufferent structura formuka
Alkanes are_____hydrocarbons
saturated
Alkenes are______hydrocarboms
unsaturated
Why are alkanes relatively unreactive?
Alkanes are relatively unreactive because the carbon-carbon single bonds in their molecules are strong and not easily broken.
What happens when alkanes burn in air or oxygen?
Compustion resction of alkanes
Alkanes burn easilty in air or oxygen to form carbon dioxide and water as steam. They burn with clear, blue, non-smoky flames because they have a low ratio of carbon to hydrogen atoms in their molecules
CH4(g)+2O2(g)→CO2(g)+2H2O
(g)
This reaction is exothermis producing large amounts of energy
Describe the substitution reactions of alkanes with halogens
Under the correct conditions, alkanes undergo substitution reactions with halogens, where hydrogen atoms in the alkane molecules are replaced by halogen atoms such as chlorine or bromine.
For the reaction to occur, energy in the form of light is required; ultraviolet lightworks best
Give an example of a substitution reaction
In bright light, methane reacts with chlorine to form
monochloromethane,
CH4(g)+Cl2(g)→CH3Cl(g)+HCl(g)
dichloromethane,
CH3Cl(g)+Cl2(g)→CH2Cl2(g)+HCl(g)
trichloromethane
CH2Cl2(g)+Cl2(g)→CHCl3(g)+HCl
tetrachloromethane
CHCl3(g)+Cl2(g)→CCl4(l)+HCl
What is the overall reaction for the substitution of methane with chlorine?
The overall reaction is CH4(g) + 4Cl2(g) → CCl4(l) + 4HCl(g).
Uses of Alkanes
Fuel
-they burn easily
-release a large amount of energy during combustion
Alkanes are used as solvents
-Alkanes are non polar
How does the color of bromine change during its reaction with alkanes?
The solution stays red-brown, and no reaction occurs between the alkane and bromine under normal laboratory conditions.
ONLY IN UV LIGHT