A perfectly efficient reaction would convert all starting reactants to products giving 100% yield.
Incomplete reactions occur because:
- reaction may be incomplete.
- there may be side reactions.
- some product is lost during transfer.
Percentage yield= actual yield(mol) X 100
Actual yield: mass of product obtained from a reaction.
Theoretical yield: maximum amount of product assuming the reaction goes by equation.
Considers the by product of a reaction as well as the desired product.
By products are considered as waste but sometimes can be sold or recycled in the reaction.
A reaction with high atom economy has minimal waste, leading to less environmental waste.
Atom economy= molecular mass of desired products X 100
sum of molecular mass of all products
Addition reactions have an atom economy of 100%
Substitution and elimination reactions have an atom economy less than 100%
Compounds with the same molecular formulae but a different structural formulae.
Chain Isomerism: hydrocarbon chain may be straight or branched.
Functional Isomerism: hydrocarbons with the same molecular formulae but different functional groups.
Positional Isomerism: isomers have the same functional groups but with different positions in the carbon chain.
Sterioisomerism: componds with the same molecular formulae, however with a different arrangement of atoms in space.
- C=C double bond must be present (cannot be twisted)
- each carbon in the double bond must be attached to two different groups.
Labelled with E when two moelcules with the biggest molecular masses are opposite.
Labelled with Z when when two moelcules with the biggest molecular masses are on the same side.
- there must be two different groups on each carbon of the C=C bond.
- two of these groups must be the same.
The cis isomer has the same group on the same side of the C=C bond.
The trans isomer has the same group opposite to eachother.