posted by believe on .
1. Student A conducted the dehydration of ethanol at 180 °C and obtained a gaseous
product. Student B conducted the same experiment at 140 °C and obtained a low-
boiling liquid. What were the products that each of the students made? Draw
mechanisms for the formation of these products. What could account for the
formation of two different products?
2. What would be the effect of decreasing the carrier gas flow rate, raising the column
temperature, have on the retention time?
3. What would be the effect of raising the column temperature and decreasing the
carrier gas flow rate on the ability to resolve two closely spaced peaks?
4. From your knowledge of the dehydration of tertiary alcohols, the alkene 2-
methylpropene should predominate in the product of the dehydration of what
1. Heating to 180 the product is ethylene gas. Heating to the lower T produces diethyl ether. We can't draw mechanisms on the boards.
2. Unclear as to what you mean. Obviously its a GC question. What do you think would happen?
3. This should follows from 2.
4. Check out the dehydration of t-butyl alcohol.
So for number 1 why does it form two products? Is it just because of the change in heat?
Alkene formation is a 1,2-elimination reaction. Ether formation is a nucleophilic substitution with the protonated alcohol as substrate and a second molecule of alcohol as nucleophile.
Can you explain why it forms diethyl ether?