How ?

Hello, this is for a lab report related to Preparation and Purification of 2-chloro-2-methylpropane, (synthesis of tert-butyl-chloride), if this is the result, how can I read this?

Ok so a feature of an IR spectrum is that you cannot identify the exact compound, only its functional groups. So the peaks you are looking for in this case will be for C-H, C-C and C-Cl bonds. Obviously most compounds have C-C and C-H bonds so to identify if this compound is present you are looking more for the C-Cl bond. My data sheet says it would have a peak somewhere between 500 and 800 on your image which there appears to be.

Now I'm not sure how much help that is alone because it only tells you a compound with a C-Cl bond is present. As your question mentions preparation and purification, perhaps you are supposed to look to see if any of the reactants are still present and therefore the sample is impure? What reactants were used and what are their functional groups? Looking at your image, there is are fairly large peaks at 1156.36 and 1369.78. Now as C-H bonds have a peak at 2850-3100 and C-C bonds have a peak at 750-1100 so whilst the 1156.36 peak could maybe be the C-C bond at a push, I can't see a bond in 2-chloro-2-methlypropane that corresponds to the 1369.78 peak. Therefore I would suggest there is an impurity. The closest match to a bond with this wavelength on my data sheet is C-F bonds at 1000-1350 but I have no bond in the range for this exact value.

I've only done IR spectrum to A level standard so maybe there is something more high level that I'm missing. Unless one of your reactants has a C-F bond I'm not entirely sure as to what more you could interpret. It appears you have got the desired product but maybe it is not pure.

Hope this helps