Flashcards
Chemistry Unit 5 Flashcards: Organic Synthesis
Flashcards do conjunto (30)
- 1List 3 artificial sweetenersSaccharin
Cyclamate
Aspartame - 2Burns with a smoky yellow flameBenzene
- 3Decolourises bromine waterAlkene
- 4Produces carbon dioxide when reacted with a metal carbonateCarb A
- 5White fumes when reacted with \(PCl_5\)OH group
- 6Yellow-orange ppt when reacted w/ 2,4-DNPHCarbonyl group (not a Carb A)
- 7Red-brown ppt with Fehling's or BenedictsAldehyde
- 8Silver mirror w/ \(AgNO_3\) + \(NH_{3(aq)}\)Aldehyde
- 9Antiseptic pale yellow crystals w/ \(I_2\) /NaOH\(CH_3\)-C=O
Or something which oxidises to it - 10Is phenol solution neutral, alkaline or acidic? Why?Acidic b/c O's LP is pushed into benzene's delocalised ring structure making the OH bond more polar so it loses \(H^+\)
- 11Can phenol be oxidised?No, it is not readily oxidised
- 122 reactions which increase chain lengthReflux w/ HCN/KCN
Friedel-Craft's alkylation - 13Names of the 2 reactions which decrease chain lengthHofmann's degradation
Hunsdiecker reaction - 14Define: hazardPotential to do harm
- 15Define: riskLikelihood of harm
- 16List 4 precautionary measures that can be taken to reduce riskUse a fume cupboard
Reduce scale
Look for an alternative safer route
Replace a reactant w/ a less toxic alternative - 172 ways of separating isomersThin-layer chromatography
Electrophoresis - 182 ways to make single isomersAsymmetric synthesis
Use of chiral auxiliaries - 19Describe combinational chemistryAN automated process by which many compounds all similar to a 'lead' compound are produced very quickly to see if they have lower side effects or more medical benefits as drugs than current treatments. They are all tested and then possibles kept in a large digital library.
- 20What is a solid phase reaction?Compounds are bonded to polystyrene-based polymer beads and the reaction takes place on them. The product remains bonded to the beads and excess reactants can be washed away.
- 21Why are sold phase reactions using polymer beads useful?Because 1 end of the reactant mol is fixed so all reactions have to happen at one end.
- 22What do you heat with during reflux?An electric heater
- 23What can be added to remove acid?\(NaHCO_3\)
- 24What is solvent extraction?When you add a solvent to a product in another solvent and the product is more soluble in the new solvent. When shaken it dissolves in the added solvent leaving impurities in the original layer, and a separating funnel can be used to tap off the lower layer, separating the product from another impurity or unwanted product which is more soluble in the other solvent.
- 25Describe re-crystalisationAdd hot solvent till solid just dissolves
Let solution cool slowly
Crystals will form but impurities won't fall out of solution because they aren't near saturation.
Remove the crystals by filtration and wash them with minimal ice cold solvent
Leave to dry. - 26What can you add to remove water from a mixture?\(CaCl_2\) granules
- 27What are inside fractional distillation columns?Glass beads
- 28How do you determine melting point?Put solid in capillary tube
Place in oil w/ thermometer
Slowly heat and stir
Read the temperature when the solid just melts. - 29How do you make cholesteryl benzoateDissolve cholesterol in pyridine
Add benzoyl chloride
Heat in a steam bath for 10 mins
Cool and add methanol
Filter off crystals of ester and wash with methanol
Recrystallise using ethyl ethanoate as a solvent. - 30How do you make methyl-3-nitrobenzoate?Dissolve methyl benzoate in cold conc sulphuric
Add 50/50 mix of conc nitric and sulphuric dropwise constantly stirring.
Stir for 15 mins
Pour over crushed ice
When melted filter off crystals
wash with water
re-crystallise w/ ethanol
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- A2 level Chemistry (Unit 5) FlashCards sobre Chemistry Unit 5 Flashcards: Organic Synthesis, criado por J000D97 em 05-04-2015.
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