Chemistry - Organic - Y12

Bromine water test

Test for alkenes, changes from orange to colourless

Oxidation of MnO4- acidified

purple to colourless Mn2+

Oxidation of MnO4- not acidified

purple to brown MnO2 solid

Potassium dichromate oxidation

turn from orange Cr2O72- to green Cr3+ ions

Elimination reactions

creates an alkene

Saytzeffs rule (poor get poorer)

major and minor products form, minor = take away H from carbon atom with most H atoms, major = take away H from carbon atom with least H atoms (adjacent to carbon with hydroxyl group)

Addition reactions

forms haloalkanes, breaks a double bond

Markovnikovs rule (rich get richer)

creates major and minor products, major = H atom will bond to C atom in double bond with most H atoms, minor = H atom bonds to C atom in double bond with least H atoms

Structural isomers

when compounds have the same formula but different structural arrangements

Geometric isomers

Only occur in alkenes, the bonds attached to the carbons in a double bond can't move about. Give two types - cis and trans

Cis isomer

when both CH3/H groups are on the same side

Trans isomer

When both CH3/H groups are on opposite sides (diagonal)

Substitution reaction

Where one atom is substituted by another atom. Example is bromine water added to an alkane.