Question

1. Briefly describe how a drying agent works. List the names and chemical formulas for five typical drying agents.

2. Elemental bromine (Br2)reacts with 3-hexene to form 3,4-dibromohexane.

a. Write out the balanced equation for this reaction.

b. If 11.5 g of 3-hexene is reacted with 8.8 g Br2, what is the theoretical yield of 3,4- dibromohexane?

c. If you did the reaction described in (c) and isolated 15.9 g of 3,4- dibromohexane, what is the percent yield for the reaction?

3. How can you tell, visually, when an organic liquid is dry after adding a drying agent?

4. Write out the mechanism for the dehydration of 2-butanol in the presence of sulfuric acid (via an E1 mechanism).

Answer 1

1. A drying agent of a soud that a beoobh water from the vicinity. I surrounding thereby making a sample or a container (sosed) any." five typical drying agents with form wue formula Name cao Caca, - Calcium oxide 1 calcium chloride I Magnesium (11) 1 mg sog Sulfate -|- Silica gel -|- Phosphorous T - Pento xide t P205 . structant it.. 2. The with chemical reaction Coll (a) CH₂ - CH₂ - CH = CH - CHa eltg et Bra CH3 - Chl, - llt ut l-eto nat ure it is 3, ho de bromo hexane Reactions occurs in 1:1 balanced " N, I. } { - hе оnu , ,но : 44 o me - Г 1. 11.5 g of 3-hexene 0.19 moles Mol wt of Bromine & 159.8 gmott 9.8 g of Bromine 0.05 mole 1: Reaction occurs in 1:1 ratio, no of moles of product formed = 0.19 -0.05 -0.09 moles

molecular wt of product Now ; molecular by Hig Br2 = 243.8 g molt !. Theoretical field : 0.09 X 243.8 Mog 1 0 - 9f 16.9 g of product is isolated, then yield = 1 btained yield xiool Theoretical yield : 15.1 x 100 21.9 yo yield - 72.Uby. When a organic ligula, say. a organic liguid, say hexane is contaminated with water, it appears like an emulsion as water and hey are in are immisable, thereby imparting the so uiguid a toteute Arans husent appearance. Thus, after proper derying the liquid looks clear and transparent 4. Given 12.-butanol) alcohol. Heg at Alq actlog UHL OH Ho 304 CH, Ut-W2012 3- CH - CH₂ - CH3 1-H2O(: & Hq is V good leaving group) CH₂ - CH - Utq - ctlenz CHg CH = Chirchg & THT than a since substituted alkene is more stable o terminal alkena, Hai C = CH-CH₂ - CH3 is formed not