Fractional distillation apparatus for

Preparation of Hydrazine. Assemble an apparatus as shown in Fig. 85b. Put an amount of potassium hydroxide into a two-neck flask provided with a reflux condenser such that there is a 2-3-mm layer of hydrazine hydrate over it. Cool the flask in a bath with ice and transfer the previously prepared hydrazine hydrate into it wear eye protection ). Pass a stream of dry nitrogen through the reaction mixture. Carefully heat the flask until the alkali dissolves completely, then cool the flask to room temperature, and, without stopping the nitrogen stream, replace the reflux condenser with a dephlegmator. Assemble an apparatus for fractional distillation (see Fig. 20) and distil off the anhydrous hydrazine in a nitrogen stream at 112-114 °C. 

When the reaction ends, rapidly transfer the product into an apparatus for fractional distillation at atmospheric pressure (see Fig. 20). Distil off the benzene at 80 °C, heating the flask on an electric stove with an enclosed coil. After distilling off the benzene, pour the water out of the cooler. Disconnect the receiver with the benzene and connect a new dry receiver. Perform further distillation and gather the fraction boiling at 172-174 °C. 

Pour the reaction mixture into the flask of an apparatus for fractional distillation under atmospheric pressure (see Fig. 20). Collect the fraction boiling at 125 °C. Pour the phosphorus thiochloride into a weighed drawn out test tube. Seal the ampoule wear eye protection ). Weigh the ampoule and the remaining parts of the test tube. Write the equation of the reaction. Calculate the yield in per cent. Test the reaction of phosphorus thiochloride with water. Write the equation of the reaction. What is the oxidation state of sulphur in this compound ... 

The resulting mixture is transferred to an apparatus for fractional distillation, and carefully fractionated, an oil bath being used for heating (Note 3). A low-boiling fraction, consisting of acetone containing some ketene, acetic acid, and a small quantity of acetic anhydride, is removed at atmospheric pressure. As the distillation progresses the temperature of the oil bath is raised to 220° over a period of about an hour and held there until three hours have elapsed from the time distillation started (Note 4). 

FIG. 6 Apparatus for fractional distillation. The position of the thermometer bulb is critical. 

B) Fractional Distillation of an Ethanol-Water Mixture. Place the 50 mL of distillate from the simple distillation experiment in a 100-mL round-bottomed flask, add one or two boiling chips, and assemble the apparatus for fractional distillation. Follow the procedure (above) for the fractional distillation of a cyclohexane-toluene mixture. Repeat the ignition test. Is any difference noted ... 

Apparatus for fractional distillation. A digital thermometer can also be used see Section 13.4 and Figure 14.12 in the Techniques. 

Apparatus A 50-mL round-bottom flask, apparatus for fractional distillation, magnetic stirring, and ffame/ess heating. 

Apparatus A 10- and a 25-mL round-bottom flask, 25-mL Erlenmeyer flask, drying tube, ice-water bath, apparatus for fractional distillation, magnetic stirring, vacuum filtration, and flameless heating. 

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