Organic 2 Review Problem 231

Organic 2 Review Problem 231 - P REPARATIONS 215 10 % N aOH...

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PREPARATIONS 215 10 % NaOH solution until the mixture attains a uniform orange colour (about 50 ml. are required). The sodium salt of methyl-orange separates as very fine particles, and filtration, if attempted directly, may be very slow. Therefore warm the mixture to 50-55°, stirring it meanwhile with a ther- mometer: when nearly all the methyl-orange has dissolved, add about 10 g. of finely powdered sodium chloride, and continue warming for a few minutes until the chloride itself has dissolved. Now allow the mixture to cool spontaneously for 10-15 minutes, and then cool in ice-water. Filter off the methyl-orange at the pump: filtration is now rapid, particularly if only gentle suction is employed, so that the particles of the methyl-orange are not dragged into the pores of the filter-paper. Drain thoroughly, and then recrystallise the methyl-orange from about ioo ml. of boiling water: filter the hot solution (if necessary) through a fluted filter- paper in a heated funnel, or a Buchner funnel which has been
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This note was uploaded on 09/19/2011 for the course CHM 2211 taught by Professor Castalleano during the Fall '06 term at University of Florida.

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