Question

1) The Material Safety Data Sheets (MSDS) for all the chemicals involved in this lab are on iLearn. Read these and answer the following questions: a) Which chemical is the most dangerous in this lab? b) Explain why you chose your answer for part a), and the safety precautions you will take when handling this material. 2) How deep into the sand should you position your flask, and why? 3) Why should you discard the first few drops of material collected? 4) Why should the “water in” hose be at the bottom of the condenser, rather than the top? 5) Why is insulating the stillhead important? 6) Explain why you must clamp the flask, not the distillation head. 7) Fill in the table below. Make sure you correctly calculate the molar amounts of your two materials.

Formula Mw bp (C) moles density amount

MTBE

Butan-1-ol Formula Mw boiling point in C moles density amount (10 ml for both)

Answer 1

3) You should discard the first few drops of material collected because the material will be impure in the beginning as it is passing through the whole set-up. After discarding, you should freshly collect the material for further use.

4) To properly condense the vapors that arise during the distillation process. If the vapors are not condensed properly, then all the solvent escapes from the reaction mixture, which causes the compound to decompose.

6) During the distillation process, the flask should be clamped because the flask is heavier than the distillation head. The flask contains all the volatiles along with the distillate, for suppose if the flask is dismantled in between, then it may cause the explosion.

7) i) MTBE:

Formula = C₅H₁₂O

Mw = 88 g/mol

bp = 55.2 ^oC

Density = 0.74 g/mL

Amount = 0.74 g/mL * 10 mL = 7.4 g

moles = 7.4 g/88 g.mol^-1 = 0.0841 mol

ii) Butan-1-ol

Formula = C₄H₁₀O

Mw = 74 g/mol

bp = 117.7 ^oC

Density = 0.81 g/mL

Amount = 0.81 g/mL * 10 mL = 8.1 g

moles = 8.1 g/74 g.mol^-1 = 0.1095 mol