Chapter 8 Flashcards
Organic chemistry
Is the study of the compunds of carbon
Hydrocarbons
Are compounds containing only hydrogens and carbons
Saturated hydrocarbons
Contain only single bonds
Unsaturated hydrocarbons
Contain double or triple bonds
Cyclic hydrocarbons
Are arranged in a ring
Unsaturated hydrocarbons make up the aromatic series with the simplest member being benzene, C6H6
Have cyclo- before the name
Properties of hydrocarbons
Insoluble in water because they are non-polar
Boiling point increases as carbon chain length increase because dispersion forces increase with the size
Alkanes
Are hydrocarbons that only contain single bonds
End in -ane
Has the formula CnH2n+2
Homologous series
Any series of organic compounds in which each successive member differs by CH2
Reactions of alkanes
Oxidation/combustion - hydrocarbons burn in oxygen to produce carbon dioxide and water
Substitution reactions - Alkanes react with halogen and they swap one of their atoms, the products are known as haloalkanes, in the presence of UV light, produces2 byproducts
Isomers
Are compounds which have the same molecular formula but different structural formulas
Alkenes
Has a double bond
Ends in -ene
Has the formula CnH2n
Reactions of alkenes
Undergo combustion/oxidation to form carbon dioxide and water
Addition reactions - react with halogens and combine and halogens replace the hydrogens, on each side of the carbon
Self addition - which the double bond breaks to form polymers
Alkynes
Contains triple bonds
Ends in -yne
Formula is CnH2n-2
Which homologus series has higher bp/mp?
Alkynes becuase they have the strongest bond
Reactions of alkynes
Undergo combustion and addition reactions
Rules for naming hydrocarbons
- Determine longest carbon chains
- Determine where the double/triple bond is
- Number the carbon atoms from the end chosen
- Name branches firstfirst with the ending -yl and include the correct prefix
- When two or more branches occur on the same carbon atoms the number is indicated for each branch and the names are given in alphabetical order
- When two or more identical branches occur on different carbon atoms, it uses the prefixes di, tri, tetra
Condensed formulas
Is a way of representing the structural formula of an organic compund in a single line
Condensed formula rules
Brackets are used to indicate side chains and if there are repeating CH groups
Fuctional group
Is an atom of group of atoms, or a bond, that gives an organic molecule its specific properties
Alcohols
Have a hydroxy group, OH as theri functional group
Named the same as hydrocarbons with the ending -ol
Properties of alcohols
Hydrogen bonding increases boiling points and because dispersion forces increase with size for non-polar molecules
Soluble in water for smaller ones because of polar hydroxy group but decreased solubility as they increase in size because of increasing non-polar sections
Reactions of alcohols
Undergo combustion to produce carbon dioxide and water
Carboxylic acids
Contain the functional group -COOH
End in -oic acid
Properties of carboxylic acids
Hydrogen bonding creates high boiling points and solubility
Reactions of functional groups
Carboxylic acids react with alcohols to make ester and water
Removes the water molecule and the leftover creates an ester which is named -yl -onoate
Where do hydrocarbons come from?
They come from crude oil which is formed from long dead organisms which are subjected to high amounts of heat and pressure over a long period of time
Fractional distillation
Crude oil is heated and passed it through a fractionating tower where it reliquidfies at the certain temperatures
Products of fractional distillation
Gas, 1-4, bottled gas Petrol, 4-12, car fuel Kerosene, 9-16, jet fuel Diesel oil, 15-25, fuel Lubrication oil, 20-70, lubricants and waxes Bitumen residue, >70, road surfaces
Thermal cracking
Placing hydrocarbons under high temperatures to crack into smaller hydrocarbons
Catalytic cracking
Using a catalyst to crack the larger into smaller hydrocarbons
Advantages of catalytic cracking
Doesnt require high energy
Increases the speed of reaction
When do you use liquid sign on combustion?
Pentane
