- Join over 1.2 million students every month
- Accelerate your learning by 29%
- Unlimited access from just £6.99 per month
AS and A Level: Organic Chemistry
Meet our team of inspirational teachers
Five equations you must know for organic chemistry
- 1 Alcohol + carboxylic acid = ester + water (eg CH3OH + CH3CH2COOH becomes CH3OOCH2CH3 + H2O)
- 2 Alkene + hydrogen = alkane (eg CH2=CH2 + H2 becomes CH3CH3)
- 3 Alkene + water = alcohol (eg CH2=CH2 + H2O becomes CH3CH2OH)
- 4 Halogenoalkane + hydroxide ion = alcohol + halide ion (eg CH3Br + OH- becomes CH3OH + Br-)
- 5 Alkene + hydrogen bromide = halogenoalkane (eg CH2=CH2 + HBr becomes CH3CH2Br)
Five facts about alcohols
- 1 Primary alcohols are oxidised into aldehydes and water, which are then oxidised into carboxylic acids. Secondary alcohols are oxidised into ketones and water. Tertiary alcohols cannot be oxidised.
- 2 Alcohols are oxidised by acidified potassium dichromate (H+/K2Cr2O7). This starts off orange and will turn green if it oxidises something (so with tertiary alcohols it will stay orange).
- 3 There are two ways of making alcohols: fermentation and hydration of alkenes. Fermentation is good because it uses renewable resources and does not take much energy, however it can only produce alcohol up to 14% before the yeast die.
- 4 Alcohols are soluble in water as they can make hydrogen bonds with the water. However, the “carbon chain” attached to the OH cannot interact with water and is insoluble. This means that alcohols become more insoluble the longer the carbon chain.
- 5 Alcohols have a very high melting and boiling point compared to alkanes of the same chain length. This is because they can form strong hydrogen bonds with each other that require a lot of energy to break.
Five facts about hydrocarbons
- 1 The longer the carbon chain the higher the higher the boiling point, as there will be more points of contact and stronger van der Waals forces.
- 2 The more branched the carbon chain the lower the boiling point, as the molecules will not be able to pack as close together and will have weaker van der Waals forces.
- 3 Hydrocarbons are insoluble in water as they cannot make intermolecular forces with them.
- 4 Hydrocarbons have low boiling and melting points as the only intermolecular forces that can hold them together are weak van der Waals forces which require little energy to break.
- 5 When processing crude oil (a hydrocarbon), the aim of the game is to get short, highly branched hydrocarbons. This will increase their volatility and make them a better fuel. We do this through: fractional distillation (sorts them into different sizes), cracking (splits long chains into short chains), isomerisation and reforming (makes the chains branched and cyclic).
- Marked by Teachers essays 7
- Peer Reviewed essays 13
Experiment to Determine Acidities of Wine. The purpose of this experiment is to determine the total and volatile acidities of each of the wines and compare them.5 star(s)
Tartaric acid requires two moles of NaOH for it to be neutralised. In order to calculate the volatile acidity of the wine, a sample of wine is evaporated using a steam evaporator, then made up to the original volume with deionised water and this process was repeated. The volatile acids evaporate away, while the remaining acids constitute what is known as the fixed acidity of the wine. This is made up to the original volume with deionised water and titrated with NaOH as before to give the acidity of this solution, which is known as the fixed acidity of the wine.The representative acid used here will again be Tartaric acid.
- Word count: 3117