B$.$ Experimental Results$-$complete in lab:

Use data given to finish the theoretical chart and graph. URGENT

Students will work in pairs $($one does simple distillation, the other fractional$)$ to collect rwo fractions and record temperatures for every half $mL$ of distillate collected. Samples collected during this experiment will be analyzed next week during GC experiment. There are $4$ mixand $55$:$45$ Respectively$).$ Each pair of students will be assigned one of these mixrures to per$-$

EXPERIMENTAL PROCEDURE

Studens will work in pains.

Simple Distillation

Transfer $10mL$ of the cyclohexane$/$toluene mixture you were assigned directly into a $25mL.$

round$-$botrom $($RB$)$ flask along wich a magnetic stir bar. Next carefully assemble the distilla$-$ tion apparatus $($see illustration in your textbook$).$ Sart by clamping the RB flask $($disilling

flask or "pot"$)$ upright to the ringstand, providing a firm foundation to support the rest of the glassware. Building from here, check that all the groundglass joints fit dightly together and Keck clips $($metal$)$ to secure connections ar both ends of the condenser. A $10mL$ graduated cylinder is used to collect distillate. A Corning hot plate$/$stirrer serves as the an aluminum heating block is needed to transfer heat around the RB flask.

Have your set up checked by your lab TA before proceeding with heating, Use an initial setting of $2$ for the hot plate, then increase this to $\frac{21}{2}$ after $30$ minutes if needed. Stirring will prevent the boiling solution from "bumping." Insulate the system with an aluminum foil "tent." Time required, from start of heating to finish of collection of distillate, should be no longer than one hour. Adjust heating if necessary, but recognize that faster distillation does not usually give better separation of componens $($emphasis on temperature control$).$

As liquid distills, record the observed remperature every half $mL$ collected. After the first $2mL$ are collected, collect a few drops in a separate labeled vial and seal the vial for GC analysis next week. Continue this distillation collecting in the graduated cylinder. After the tempera$-$ ture changes and $2mL$ of the higher boiling component are distilled, collect a few drops in separate labeled vial and seal the vial for analysis during GC experiment. Finish the distillatio once you reach $7mL.$ Do not artempe to collect more than $7mL($do not distill the pot once you reach $7mL.$ Do not attempt to collect more than $7mL($do not distill the pot to dry notebook in the form of a table. Discard this cyclohexane$/$toluene mixture from the gratur cylinder after distition in the designated waste container within the hood tube, and bet two vials to your TA for further analysis next lab. Lift che distillation apparatus and separa from the aluminum heating block, then allow everyching to cool then your glassware with soap water and final rinse with acetone.

Fractional Distillation

Follow the guidelines given above with just one addition. Insert a fractionating column between the $25mL$ RB flask and three$-$way adapter $("$distillation head"$).$ The fractionating colEven whough this piece looks very similar to your warer$-$cooled conded $\frac{2}{3}$ with glass beads. ranning uater' Insulate the column with the insulation material provided in the lab, topping it

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with foil. Record temperature vs$.$ volume data as above, up to a $7mL$ maximum, and collect the same two fractions as above. Exchange the temperature data with your lab partner prior to departing from lab this period. Make sure to seal the vials, label them and give to your TA for

Safety

Cyclohexane is an irritant flammable liquid $($bp $81C)$; minimize exposurel Toluene is an irritant and flammablel Be very careful handling any part of this set$-$up after this glassware will retillation. The aluminum heating block and many of the pieces of

Waste Disposal

$.$ Distillate and any liquid left in RB flask$$bottle labeled "Waste Expt# $6"$

B$.$ Experimental Results$-$complete in lab:

$\backslash$table$[[\backslash$table$[[$Vol$],[(mL)$