synthesis of t-pentyl chloride (orgo lab 2)

what kind of reaction is being performed? also what is a competing reaction in our process? why is there a possibility for a competing reaction to occur?

we are performing an SN1 reaction with HCl; a competing reaction that may occur is an E1 reaction. this is possible due to an E1 reaction and an SN1 reaction BOTH going through a carbocation intermediate.

for our desired reaction type, how will the chloride ion act? with this in mind, how is it able to pair with our carbocation intermediate?

our chloride ion (with a - charge) acts as a weak nucleophile, but our carbocation is a very strong electrophile due to being electron deficient.

for our NOT desired reaction type, how will our chloride ion react? how will it act / do more specifically

in the E1 reaction, the chloride ion acts as a BASE and deprotonates a carbon close to the “+” on the carbocation. this ends up forming an alkane product.

in this reaction sequence, what is our leaving group? what intermediate is produced once the leaving group has separated?

our leaving group is H2O, this forms a carbocation intermediate.

how can we tell that our desired product was made? what would we expect on an IR if our product was made, and if our other product was not made?

what does miscible mean? what qualities / properties should our miscible liquids have in order for the distillation to go correctly.

miscible = the liquids form a homogenous mixture (do not separate into layers)

the 2 liquids should have 2 very different boiling points so that we can heat the mix up to the temp of 1 liquid, but below the bp of another compound. we will collect and condense compound 1.

where should our thermometer be placed during the distillation? why in this spot? explain.

it must be placed so that the red bulb is just above the hickman head, it cannot be inside the conical vial or touching the liquid within. this is because we want to measure the temperature of the VAPOR we are condensing.

what is an azetrope? what is it’s BP like?

an azetrope is a mixture of 2+ liquids that when boiled the vapors contain all constituents proportionally. it’s BP is much lower than at any individual BP of the combined liquids.

draw and show the steps of the proper reaction sequence of our reactant.

what do we use to confirm purity of our isolate? what would we expect on the IR reading if our proper reaction occurred? what would we expect if it did not occur correctly?

we use IR spectroscopy. if our isolate was concentrated and distilled correctly, we would expect to not have an OH stretch anymore, as well as GAIN a c-cl stretch. if our undesired reaction occurs, we would expect to see a c=c stretch showing presence of an alkane.

what is the purpose of adding sodium bicarbonate to the organic layer? what reaction occurs?

the purpose of adding it is to neutralize the HCl within the solution. this also causes there to be a production of CO2 (g) + NaCl (aq) + and H2O (l)

why do we only collect material that boils between 80 to 84 degrees C? what happens if we go any higher or lower than this?

because this temp range corresponds to the BP range of 2-chloro-2-methylbutane ( our desired product ). if we change the temp we are collecting from, then we will distill the wrong products, and possibly generate even more of the incorrect product than anticipated.