Homologous Series Flashcards
What is meant by the term homologous series
A family of hydrocarbons with the same general formula and similar chemical properties, that show a gradual change in physical properties
State what is meant by the term isomer.
Compounds with the same molecular formula, but different structural formula
Num of carbon prefixes
meth- 1 eth - 2 prop - 3 but - 4 pent - 5 hex - 6 hept - 7 oct - 8 noc - 9
Alkane Formula
Two hydrogens to a carbon plus two end carbons
CnH2n+2
Alkenes Formula
Number of hydrogens is exactly double the number of carbons
CnH2n
Cycloalkanes Formula
CₙH₂ₙ₊₂
What is a hydrocarbon?
Hydrocarbon is a compound containing hydrogen and carbon only
State the prefixes for number of carbons in hydrocarbons:
1 carbon = meth- 2 carbons = eth- 3 carbons = prop- 4 carbons = but- 5 carbons = pent- 6 carbons = hex- 7 carbons = hept- 8 carbons = oct-
What is a homologous series?
A homologous series is a family of compounds with the same general formula and similar chemical properties.
Why are alkanes described as saturated?
The carbon to carbon bonds in alkanes are all single bonds.
Why are alkenes described as unsaturated?
Unsaturated hydrocarbons contain at least one double or triple carbon to carbon bond.
What is the test for unsaturation?
The test for unsaturation is addition of a few drops of bromine water which will quickly be decolourised.
Alkenes are more reactive than alkanes because they have a double bond.
What type of reaction occurs when reactants such as Hydrogen or Chlorine attacks and breaks the double bond?
Addition reaction
What is formed when an alkene undergoes an addition reaction with hydrogen?
Alkane
Define isomers.
Isomers have the same molecular formula (same numbers of carbons and hydrogens) but different structural formulae
