The extraction process is when a solvent, dichloromethane (15mL) is added to the filtrate in a separatory funnel; the mixture is gently swirled together 3 times, and stopcock is released in between to vent the funnel. Dichloromethane (including the emulsion) is then drained from the bottom into a 50mL Erlenmeyer flask. Same extraction process is repeated on the same filtrate and the dichloromethane is, once again, let out to the same 50mL Erlenmeyer flask as before. The combined dichloromethane solution and water (20mL) is poured into a rinsed separatory funnel. Mixture is gently swirled and drained out into an Erlenmeyer flask.
Pour all the filtrate and washings into a 250cm3 volumetric flask. Make up to 250cm3 with 1.0mol dm-3 sulphuric acid(VI) acid. Stopper the flask and invert several times to thoroughly mix the solution. 5. Fill the burette with 0.005mol dm-3 potassium manganate(VII) solution.
This solution was added drop wise to the stirred ethanolic solution of benzophenone at room temperature. After all the sodium borohydride being added, the mixture was stirred for a further 10min. Meanwhile, ice water (10ml) was mixed with concentrated hydrochloric acid (1ml) in 50ml beaker. To this the mixture of sodium borohydride and benzophenone was poured slowly into the beaker. The precipitate was collected using suction filtration and washed with 2 x 5ml portions of water.
Due to this, the reaction takes place in acidic conditions by adding concentrated sulfuric acid to the solution. The sulfuric acid protonates the alcohol group in triphenylmethanol. The ether is formed when the carbocation reacts with methanol to form trityl methyl ether. H3O + + CH3OH Triphenylmethanol Trityl Methyl Ether Procedure: Approximately 0.1g of triphenylmethanol crystals was placed into a reaction tube and grinded to fine powder with a glass rod. 1ml of concentrated H2SO4 was then added to the tube and the solution was continuously stirred to dissolve all the triphenylmethanol.
The watch glass was removed with the beaker tongs. Using a rubber bulb and a stirring rod to stir the solution continuously, 15.00mL of .25M BaCl2 solution was added to the solution in the beaker. The watch glass is replaced and the solution is keep hot but not boiling for 15 minutes. The precipitate was allowed to settle. When the liquid above the precipitate was clear, the solution was tested for completeness of precipitation when a few drops of BaCl2 solution were added from a pipette.
Put aspirin powder in a beaker and pipette exactly 30 cm3 of a 1 M NaOH solution onto the powder. Stir the beaker in order to dissolve aspirin completely. 3. Add 3 drops of phenolphthalein to the beaker with aspirin powder and NaOH solution. NaOH solution would be in excess and thus prepare 1 M of HNO3 solution in burette, which will be used in back-titration.
* The sodium carbonate solution was poured into the beaker with the calcium chloride solution. * A sheet of filter paper was folded in half twice and weighed. (1.1g)/(0.7g) * The filter paper was placed in a funnel in a paper cup. * The contents of the beaker were swirled to dislodge any participate from the sides and then slowly poured through the funnel. * 5ml of distilled water was poured down the sides of the beaker, swirled and poured into the funnel.
c.2 grams KI. d.10 mL of 2M H2SO4. 5.Mix the ingredients in the Erlenmeyer flask completely. 6.Immediately begin to titrate with thiosulfate. 7.Titrate until the solution gives off a pale yellow color.
When the solution is acidified during diazotization to form nitrous acid, the sulfanilic acid is precipitated out of solution as a finely divided solid, which is immediately diazotized. The finely divided diazonium salt is allowed to react immediately with dimethlaniline in the solution in which it was precipitated. Mechanism Diazotization: [pic] Diazo Coupling: Methyl orange is often used as an acid-base indicator. In solutions that are more basic than pH 4.4, methyl orange exists almost entirely as the yellow negative ion. In solutions that are more acidic than pH 3.2, it is protonated to form a red dipolar ion.
Recrystallise the crude ester from methanol using a quantity of hot solvent approximately twice the minimum required for complete solution (This is to ensure that the phenyl benzoate does not separate until the temperature of the solution has fallen below the melting point of the ester). Phenyl benzoate separates as colourless crystals. 5. Determine the melting point of the product. Results : Yield (mass in gram) = __________________0.128 g_____________________ Melting point of pure phenyl benzoate (OC) = ___________70O______________ Melting point of your phenyl benzoate (OC) = ___________69O______________ Questions : 1.