key ideas key words
C10 Organic Reactions
C10.1 - Reactions of Alkenes
Alkenes: a series of unsaturated hydrocarbons (because they have a double carbon-carbon
bond), such as ethene ( 2 carbons), propene (3), butene (4) and pentene (5)
❖ The double bond means that two fewer hydrogens are present in alkenes than alkanes
(as the two bonds are used up by the carbons), which makes them unsaturated
❖ The double bond makes alkenes far more reactive than alkanes as they can open up to
form single bonds in things like polymers
❖ When drawing out the structure of an alkene, remember to make sure each carbon is
making only 4 bonds
❖ Alkenes burn with a smokier, yellow flame as they take part in incomplete combustion,
meaning that they are less energy-efficient than alkanes
alkene + oxygen = carbon + carbon monoxide + carbon dioxide + water (+energy)
❖ However, in large amounts of oxygen, alkenes can combust completely to make the
products of carbon dioxide and water
alkene + (large amount of) oxygen = carbon dioxide + water (+energy)
, key ideas key words
Reaction with Halogens Reaction with Hydrogen Reaction with Steam
addition reactions with addition reaction where the water and an alkene can react
halogens such as bromine, double bonds open up to to form an alcohol when
chlorine and iodine to form form a saturated molecule in passed over a catalyst and this
saturated molecules the presence of a catalyst. reaction is reversible
when this happens, the
when this happens, the alkene goes from orange to (eg. ethene + steam =
alkene goes from orange to colourless ethanol)
colourless
(eg. pentene + hydrogen =
(eg. ethene + bromine = pentane)
dibromoethane)
in the food industry,
hydrogenation is used to
make spreadable fats
C10.2 - Structures of Alcohols, Carboxylic Acids and Esters
❖ Alcohols have the functional group of:
❖ The first four alcohols you need to know are methanol, ethanol, propanol and
butanol
❖ When writing the formula for alcohols, for example, methanol, instead of writing
CH4O (which is still correct), it does highlight the functional group that would
C10 Organic Reactions
C10.1 - Reactions of Alkenes
Alkenes: a series of unsaturated hydrocarbons (because they have a double carbon-carbon
bond), such as ethene ( 2 carbons), propene (3), butene (4) and pentene (5)
❖ The double bond means that two fewer hydrogens are present in alkenes than alkanes
(as the two bonds are used up by the carbons), which makes them unsaturated
❖ The double bond makes alkenes far more reactive than alkanes as they can open up to
form single bonds in things like polymers
❖ When drawing out the structure of an alkene, remember to make sure each carbon is
making only 4 bonds
❖ Alkenes burn with a smokier, yellow flame as they take part in incomplete combustion,
meaning that they are less energy-efficient than alkanes
alkene + oxygen = carbon + carbon monoxide + carbon dioxide + water (+energy)
❖ However, in large amounts of oxygen, alkenes can combust completely to make the
products of carbon dioxide and water
alkene + (large amount of) oxygen = carbon dioxide + water (+energy)
, key ideas key words
Reaction with Halogens Reaction with Hydrogen Reaction with Steam
addition reactions with addition reaction where the water and an alkene can react
halogens such as bromine, double bonds open up to to form an alcohol when
chlorine and iodine to form form a saturated molecule in passed over a catalyst and this
saturated molecules the presence of a catalyst. reaction is reversible
when this happens, the
when this happens, the alkene goes from orange to (eg. ethene + steam =
alkene goes from orange to colourless ethanol)
colourless
(eg. pentene + hydrogen =
(eg. ethene + bromine = pentane)
dibromoethane)
in the food industry,
hydrogenation is used to
make spreadable fats
C10.2 - Structures of Alcohols, Carboxylic Acids and Esters
❖ Alcohols have the functional group of:
❖ The first four alcohols you need to know are methanol, ethanol, propanol and
butanol
❖ When writing the formula for alcohols, for example, methanol, instead of writing
CH4O (which is still correct), it does highlight the functional group that would
