Required Practicals - Organic

Use a reaction which has a visible change, e.g. formation of precipitation. 1. Set up 5 water baths of different temperatures to heat up seperate samples of reactants. 2. Place a conical flask with and X on the bottom in each water bath. 3. For the first temperature, add both reactants to the conical flask and start the timer. 4. Record the amount of time taken for the cross to no longer be visible 5. Repeat this for each temperature 6. For each time, calculate 1/t (s-1) for relative rate 7. Plot the results of rate against temperature on a graph

• Preperation - reacting suitable quantities of reactants to form impure product, e.g. reflux or distillation • Seperation - seperate out impure product from reaction mixture through fractional or simple distillation • Purification - remove unreacted impurities and by-products • Dehydration - remove excess water • Final distillation

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Breaks down larger bubbles to help keep a smooth and even boiling. Prevents reaction mixture splashing into the condenser.

Simple distillation has a still head, whilst fractional distillation has a fractioning column.

• Place organic liquid in a seperating funnel and add a portion of aqueous solution (most often NaHCO3, to remove acidic impurities) • stopper and shake, releasing the pressure every now and then (usually from CO2) • Allow the seperating funnel to stand and aqueous and organic layers to seperate. • Run off and discard the aqueous layer, and run off the organic layer into a beaker for use. • Repeat the process again

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• Add a spatula of a drying agent to the organic liquid in a beaker. • Swirl • Add more of the drying agent until the liquid turns from cloudy to clear • set up filtering appartatus and fliter organic liquid into a clean dry conical flask through fluted filter paper.

To check the purity of the organic liquid. If the boiling point is sharp and correlates to the value in the data book, it indicates a pure sample.

• Water displacement • Gas syringe • Mass loss • Quenching • Colorimetry

Measure a value every 10 seconds, using it to plot a graph of said value against time. A tangent can be using to calculate rate of reaction. Repeat with different concentrations and plot a graph to find order.

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• A solution is created with acid, Iodide ions, sodium thiosulfate and starch. • Hydrogen peroxide is added and the time is recorded for the solution to turn blue/black • The experiment is repeated with different concentration of Iodide ions, whilst the overall volume and concentrations of other reactants remains the same • This can be plotted as a graph of Iodide conc against 1/t (s-1) and used to determine the order of the reaction. It can also be used to determine rate through drawing a tangent.

As iodine ions are produced, they react with the known volume of sodium thiosulfate, and so starch does not change colour until all of the sodium thiosulfate has reacted with Iodine.

• Preperation - react suitable quantities of reactants to produce an impure product • Filtration - Seperate the solid from the reaction mixture through suction filtration • Purification of the product • Checking the purity

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• A solvent is chosen in which the desired product dissolves readily at higher temperatures but is only slightly solube at room temperature • A minimum volume of hot solvent is used to dissolve the solid, making a saturated solution • Filter the solution whilst hot using fluted filter paper, to remove any insoluble impurities • Cool filtrate slowly in an icebath, until solid recrystalises • Filter by suction filtration using a Buchner Funnel • Wash with cold solvent to remove aqueous impurities • Dry out sample through sucking air over the buchner funnel and placing sample in a low temperature oven (or use desiccator) Repeat steps 2-6 for purer product

• Place some solid in a melting point capillary tube that is sealed at one end. • Place in melting point apparatus and heat slowly • Record the range over which the solid mels. The sharper the range, the more pure the product. • Compare the melting point to values in a data book.