CHEMISTRY 3.5 Paper 1. Describe the structure and reactions of organic compounds containing selected organic groups

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1 CHEMISTRY 3.5 Pper 1 Describe the structure nd rections of orgnic compounds contining selected orgnic groups Credits: Five INSTRUCTIONS Answer ALL questions NZQA/Person Eduction 2006

2 - 2 - You re dvised to spend bout 50 minutes nswering these questions. Question One (Bursry 2003 Question 3: modified) The following dt re extrcted from the Properties of Orgnic Compounds in Dt Book. Use these dt to nswer the questions tht follow. Give the formul of secondry lcohol listed in the tble bove. A

3 b Write the nmes of TWO compounds from the tble tht re structurl isomers. A nd c But-2-ene hs two geometricl isomers. Drw nd lbel the two geometric isomers of but-2-ene. A Explin why there re no geometric isomers of but-1-ene. A M Question Two (Bursry 2003 Question 5: modified) Drw the structurl formul of the orgnic compound with THREE crbon toms tht mtches ech of the descriptions given below. A M i hydrocrbon tht rpidly decolourises cidified potssium permngnte solution ii compound tht is oxidised to ketone iii n ester

4 b Write formule for the missing rectnts or products for ech of the following rections. A M i CH 3 CH 2 CH=CH 2 + HBr ii CH 3 CH=CHCH 3 + H 2 O [mjor product] iii Circle the word below tht best describes the type of rection occurring in the rection in ii bove. Addition Elimintion Oxidtion Substitution c An unlbelled bottle is known to contin only one of the following compounds: In order to identify the unknown compound, smll smples from the bottle were treted in the following wys: A B C D dded to wter nd then tested with litmus dded to solution of bromine dded to solution of mmonicl silver nitrte (Tollens regent) nd wrmed wrmed with n cidic solution of potssium dichromte. i Complete the tble below by writing the formul for the compound(s) tht will be identified by ech step A to D nd the expected observtions tht will be mde if these compounds re present. Rection Compounds identified Expected observtions A B C D A M E

5 ii Write the formul of the compound tht does not rect with ny of the regents in A D bove nd nme the functionl group tht it contins. A Formul: Functionl group: d Study the rection flow digrm below. i ii Nme the strting regent. A Complete the flow digrm by writing the structurl formul for the orgnic product of ech rection nd nming it. A M E

6 - 6 - Question Three (Bursry 2002 Question 2: modified) The compound mimosine, shown below, is nturl product found in lrge quntities in the seeds nd folige of some plnts. b Mrk with * the crbon responsible for the opticlly isomeric properties of this compound. A Nme THREE different functionl groups found in the bove structure. A Question Four (Bursry 2002 Question 4: modified) When bromolkne is mixed with queous sodium hydroxide nd boiled t 71 C for 40 minutes, hydrolysis rection occurs. The hydrolysis rection is crried out using the pprtus in the digrm shown below. i Nme the process tht uses this pprtus. A ii Nme the piece of equipment mrked A in the digrm bove. A iii Explin why it is necessry to use this pprtus for the hydrolysis rection. A M

7 b When bromolknes re heted with KOH in ethnol, n elimintion rection occurs. Complete the following eqution by drwing the orgnic product of the rection. A c The lbels hve fllen off four bottles of orgnic liquids. They re known to be: ethnoyl chloride propnmine 1-chlorobutne cyclohexene Devise simple method to identify the contents of ech bottle using only wter, queous bromine nd litmus s testing regents. A M E

8 - 8 - Question Five (Bursry 2002 Question 5: modified) Perspex nd Nylon 6,6 re synthetic polymers. i Complete the tble below by drwing the repeting unit of these polymers. A M Polymer Monomers Repeting Unit of the Polymer Perspex Nylon 6,6 The dicyl chloride monomer for the synthesis of nylon 6,6 cn be mde in the lbortory using 1,6 dibromohexne. ii Complete the flow digrm below to show how this could be done. Write the regents in the boxes mrked R nd the compounds formed in the boxes mrked P. A M E b Amino cids re linked together to form proteins. Protein nd strch re exmples of nturlly occurring polymers. i Nme the monomer from which strch is mde. A Alnine is simple mino cid. It hs the structure: ii Drw box round the group of toms tht cuses the mino cid to behve s bse. A

9 c Electrophoresis is process by which different mino cids cn be seprted using n electric field. In cidic conditions, the mino cid forms n ion tht will move towrds one electrode. In bsic conditions, it forms nother ion tht will move towrds the other electrode. Explin how the conditions described bove give rise to two ions tht will move towrds the two different electrodes nd stte which electrodes in ech cse. A M Question Six (Bursry 2002 Question 11: modified) Although fts re solids nd oils re liquids t room temperture, they hve the sme bsic chemicl structure, ie they re triesters of glycerol. The structure of ft or oil cn be represented s: Drw the structure of glycerol nd write its systemtic nme. A Nme:

10 The tble below lists some common ftty cids tht rect to mke fts nd oils. Number of Crbon Atoms Systemtic Nme Trivil Nme Structurl Formul 12 dodecnoic cid luric CH 3 (CH 2 ) 10 COOH 14 tetrdecnoic cid myristic CH 3 (CH 2 ) 12 COOH 16 hexdecnoic cid plmitic CH 3 (CH 2 ) 14 COOH cis hexdec 9 enoic cid plmitoleic CH 3 (CH 2 ) 5 CH=CHCH 2 (CH 2 ) 6 COOH 18 octdecnoic cid steric CH 3 (CH 2 ) 16 COOH cis octdec 9 enoic cid oleic CH 3 (CH 2 ) 7 CH=CHCH 2 (CH 2 ) 6 COOH cis,cis octdec 9,12 dienoic cid linoleic CH 3 (CH 2 ) 4 (CH=CHCH 2 ) 2 (CH 2 ) 6 COOH cis,cis,cis octdec 9,12,15 trienoic cid linolenic CH 3 CH 2 (CH=CHCH 2 ) 3 (CH 2 ) 6 COOH b Give n exmple from the tble of n cid tht is: i sturted: A ii monounsturted: A Most of the nturlly occurring cids re of the cis vriety, but during hydrogention some of the cis double bonds re chnged into trns double bonds. It is now believed tht trns ftty cids my be responsible for certin hert diseses. c Wht must hppen to the double bond for the cis isomer to be chnged into the trns isomer? A M