C3 Review PowerPoint Presentation

 1 mole of = 24dm 3 (at room temperature and a gas atmospheric pressure) A GAS SYRINGE is used to collect gases during reactions to allow molar gas calculations to be performed

 Nitrogenous fertilisers (ones that contain Nitrogen) are manufactured from AMMONIA. These fertilisers are used to promote plant growth. These fertilisers increase the yield of crops that are produced.  If these fertilisers are used excessively then this can lead to run off into rivers and lakes (or any other water source). This results in excessive plant growth (EUTROPHICATION). When these plants die they decompose by bacteria which uses up the OXYGEN.

 The HABER process is a REVERSIBLE reaction which will reach DYNAMIC EQUILLIBRIUM.  Dynamic equilibrium is where the FORWARDS and BACKWARDS reactions are happening at the same rate.

 When AMMONIA is formed it releases heat (EXOTHERMIC). This is the FORWARDS reaction.  The reverse reaction will be the opposite which makes it ENDOTHERMIC (takes in heat)  When DYNAMIC EQUILLIBRIUM is reached these two reactions occur at the SAME RATE.  Adjusting the temperature and pressure will affect the position of the equilibrium, favour the PRODUCT or REACTANT.

N H 2 ⇌ 2 NH 3  Reactant = 4 molecules  Products = 2 molecules Pressure and the Haber process  If you increased the pressure of the reaction the equilibrium would favour the PRODUCTS (move to the right). This is because the particles are being forced closer together and therefore more likely to react. Temperature and the Haber process  As the reaction is EXOTHERMIC it favours cooler conditions (it releases energy into the surrounding environment).  An increase in temperature would move the equilibrium to the left (favour the reactants).  A low temperature would increase the yield but slow the rate of reaction.

 Optimal conditions are used to ensure that the maximum possible yield is produced safely and at a sufficient rate to be economically viable.  Temperature – approx. 450OC  Pressure – 200atm (200 times atmospheric)  Catalyst – Iron catalyst  A catalyst increases the rate of reaction without ever being used in the reaction. It works by lowering the activation energy for the reaction (energy required for a successful collision)  If the temperature or pressure is too high then there can be safety implications and too low will result in a lower yield.

 Ethanol (alcohol) can be produced by the fermentation of CARBOHYDRATES (sugars).  Fermentation occurs when YEAST convert sugars into alcohol. The yeast act as an ENZYME.  For this to happen successfully the following conditions must be sustained: ◦ Kept warm (allow the bacteria to work successfully, too hot will kill them) ◦ Anaerobic conditions (no oxygen)

 Different types of alcoholic drink contain different percentages of ethanol. The higher the alcohol content the higher % it is given.  1 unit of alcohol = 10cm3 pure ethanol  The effects of alcohol are: ◦ Slower reaction times ◦ Violent/aggressive behaviour ◦ Loss of balance/coordination ◦ Vomiting and fainting ◦ Dehydration  Prolonged alcohol consumption can result in an increased risk of HEART DISEASE, STROKE or LIVER CIRROHISIS.  Alcoholic spirits are made by FRACTINAL DISTILLATION where the ethanol is removed first and the water is left behind (increasing the alcoholic content)

Ethanol can be produced in two main ways: 1. Fermentation – sugars are turned into ethanol and carbon dioxide through the anaerobic respiration of YEAST. 2. Hydration of Ethene (crude oil fraction) – reacting ethene with steam in the presence of a catalyst (addition reaction)

 Each method of Ethanol production has both social, environmental and economical advantages and disadvantages.  This information needs to be evaluated to determine the best method of production for individual cases. Making Ethene  Ethene can be made by the cracking of CRUDE OIL but also the DEHYDRATION of Ethanol.

 Alkanes – a hydrocarbon containing only C-C bonds.  Alkenes – a hydrocarbon containing at least one C=C bond.  Alcohol – a hydrocarbon containing at least one –O-H group. A HOMOLOGOUS series is a series of compounds that have the same general formula and similar chemical properties but have variation in boiling points.

 Ethanoic acid is a CARBOXYLIC ACID.  It is the active ingredient in VINEGAR.  It is produced by the OXIDATION of ethanol (under aerobic conditions).  It has a sharp, sour taste and can be used as a PRESERVATIVE.  Ethanoic acid reacts with metals to form salts (ending – ethanoate).  Carboxylic acids react in the same way as normal acids. They are classified as weak acids.  Carboxylic acids are named in the same way as other homologous series. Their ending is –anoic acid.  Their functional group is –COOH.

 Esters are made during the reaction of ALCOHOLS and CARBOXYLIC ACIDS.  They are commonly used as FLAVOURINGS and FRAGRANCES as they have distinctive smells and tastes.  Ethanol reacts with ethanoic acid to from the ester ETHYL ETHANOATE.  Esters can also be turned into FIBRES to make FABRICS – POLYESTER.  Polyesters can be recycled to form FLEECE.

 Fats and Oils are big esters. The only difference is fats are SOLID at room temperature where as oils are LIQUID.  Soaps can be made from fats and oils by heating with a concentrated alkali.  Oils are commonly UNSATURATED (contain C=C bonds).  Fats are SATURATED (contain C-C bonds).  To turn an oil into a fat you must HYDROGENATE it (addition of Hydrogen)

 How do Soaps work?  A soap can be shown as a tadpole shape – head is water loving (HYROPHILLIC) and tail is water hating (HYDROPHOBIC).  The head has a negatively charged oxygen ion (anion).  The tail is a hydrocarbon (water hating)  Hydrophobic tail sticks into grease.  Hydrophilic end sticks out to attract water.  Grease particle surrounded by hydrophilic heads.  Removed by water attraction (grease can now mix with water)