chem 31 - laboratory manual

7/25/2019 CHEM 31 - Laboratory Manual

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Experiment No. 1SOME DIFFERENCES IN PROPERTIES BETWEEN ORGANIC AND

INORGANIC COMPOUNDS

Name: Date:

Tea!"er#$ $i%nat&re:

I. PRE'(AB:

Cite three signifcance o organic chemistry to everyday lives

1. ____________________________________________________________________________________________________________________________________

2. __________________________________________________________________

__________________________________________________________________

3. ____________________________________________________________________________________________________________________________________

II. OB)ECTI*E:To study some common dierences in properties between organic andinorganic compounds

III. APPARATUS:

unsen burner !ials"atch glass !ial brushCrucible tong

I*. MATERIA(S:

#rops o the ollowing$ %inch o the ollowing$&.1 ' potassium permanganate Table salt( ' suluric acid )ugar&.1 ' iron *++, sulate )andCoconut oil )tarch

-erosene#enatured alcohol

%iece o$luminum oil"a/0ea%lastic

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*. PROCEDURE

1. Compo$ition

n a piece o broen crucible4 heat strongly each o the ollowing$

pinch o sugar pinch o sand

piece o plastic

piece o aluminum oil

pinch o starch

piece o lea

"rite observations and classiy each substance as to organic or inorganicsubstance.

bservation rganic 5 +norganic

)ugar

)and

%lastic

luminumoil

)tarch

0ea

"hat element is common to all organic compounds6 _______________.

+. Com,&$ti,i-it

+gnite a small piece o wa/ placed on a broen crucible. bserve. 7epeat withgrains o table salt.

"rite observations and classiy each substance as to organic or inorganicsubstance.


"a/

Table salt

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8/planation$________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

/. So-&,i-it

%lace in separate vials4 3 drops o coconut oil and grains o table salt. To eachvial4 add 1& drops o water. )hae. bserve.

7epeat the above procedure using erosene instead o water. bserve. "riteobservations and classiy each substance as to organic and inorganicsubstances.

"ater -erosene rganic 5 +norganic

Coconut il

Table salt

8/planation$________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

0. Rate$ o Rea!tion

%lace 9 drops o reshly prepared &.1 ' :e);in a clean vial. dd 2 drops o ('


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8/planation$______________________________________________________________________________

__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________POST'(AB:

)ummari?e the dierences between properties o organic and inorganiccompounds. Tabulate your answers.

Experiment No. +

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COMPOSITION OF MOST ORGANIC COMPOUNDS

Name: Date:Tea!"er#$ $i%nat&re:

I. PRE'(AB:

#efne rganic Chemistry___________________________________________________________________________________________________________________________________________________________

@ive three reasons why carbon can orm many dierent compounds.

1. __________________________________________________________________

__________________________________________________________________

2. ____________________________________________________________________________________________________________________________________

3. ____________________________________________________________________________________________________________________________________

II. OB)ECTI*E:

To test or the presence o elements common to most organic

compounds

III. APPARATUS:

unsen burner!ialsCopper wire

I*. MATERIA(S:

#rops o$

conc. 0ead acetate4 conc. mmonium molybdate1& m0 1' sodium hydro/ide 1 m0 conc. =itric acid1 ml conc. )uluric acid Chloroorm0itmus paper 'il#ry egg albumin

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*. PROCEDURE:

Carbon4 hydrogen and o/ygen with small amount o halogens4 nitrogen4sulur and phosphorous are the chie elements ound in organic compounds.

A. Car,on an2 32ro%enOrganic compounds are frequently inammable and when heated take reor char.


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7epeat the above procedure using ew strands o hair instead o eggalbumin.

"hat is the color o the precipitate6 _____________________

@ive the name and ormula o the precipitate.

8Auation.

D. P"o$p"or&$On oxidation, phosphorous change to phosphate, which forms yellowprecipitate with ammonium molybdate.

To 9 drops o mil in a vial add 9 drops o conc. =itric acid and 9 drops o

conc. )uluric acid. oil in a water bath or 9 minutes. Cool the vial and dilutethe solution with eAual volumes o water. dd ew drops o conc. mmoniummolybdate and warm. bserve the color o the precipitate ormed.

bservations.

_______________________________ precipitate indicates the presence ophosphorous.

8Auation.

E. 3a-o%en$


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POST'(AB:

1. "hat element5s is5are common to organic compounds6__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. "hy is it more diEcult to test the presence o chlorine in organiccompounds than in inorganic compounds6__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. "hen a piece o hardFboiled egg is let in contact with a silver spoon4 ablac spot ormed on the spoon. 8/plain.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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Experiment No. /PURIFICATION OF ORGANIC COMPOUNDS

Name: Date: Tea!"er$ Si%nat&re:

I. PRE'(AB:

1. "hat is crystal and what is meant by recrystalli?ation6__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2.


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I*. MATERIA(S:+mpure cetanilide *G& H acetanilide > 1& H =aCl and trace o red

dye,

ctivated charcoalen?oic acidChloroormdil. =itric acid+ce#istilled water)odium chloride)ilver nitrate

*. PROCEDURE:

A. P&ri4!ation o So-i2$ , Re!r$ta--i5ation

he products of chemical reactions can be impure. !urication ofproducts must be performed to remove by"products and impurities. Liquidsare customarily puried by distillation, while solids are puried byrecrystalli#ation $sometimes called simply %crystallization%&.

'ecrystalli#ation is a method of purifying a solid. here are two typesof impurities( those more soluble in a given solvent than the maincomponent and those less soluble. $)f there are any impurities that have thesame solubility as the main component, then a di*erent solvent needs to bechosen.&

'ecrystalli#ation relies on the di*erent solubilities of solutes in asolvent. +ompounds, which are less soluble, will crystalli#e rst. hecrystalli#ation process itself helps in the purication because as the crystalsform, they select the correct molecules, which t into the crystal lattice andignore the wrong molecules. his is of course not a perfect process, but itdoes increase the purity of the nal product.

he solubility of the compound in the solvent used for recrystalli#ationis important. )n the ideal case, the solvent would completely dissolve thecompound to be puried at high temperature, usually the boiling point of thesolvent, and the compound would be completely insoluble in that solvent atroom temperature or at o+. )n addition the impurity either would be

completely insoluble in the particular solvent at the high temperature, orwould be very soluble in the solvent at low temperature. )n the former case,the impurity could be ltered o* at high temperature, while in the latter casethe impurity would completely stay in solution upon cooling. )n the realworld, this will never happen and recrystalli#ation is a technique that has tobe practiced and perfected.

'egardless of crystalli#ation method, the purity of the solid can beveried by taking the melting point.

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- good $suitable& recrystalli#ation solvent will dissolve a large amountof the impure compound at temperatures near the boiling point of thesolvent. mall amount of compound being puried should remain in solutionat low temperatures, between approximately /0 and 10 o+. Low solubility atlow temperatures minimi#es the amount of puried compound that will lose

during recrystalli#ation.- suitable recrystalli#ation solvent should also be partially volatile inorder to be easily removed from the puried crystals. he solvent should notreact with the compound being puried and it should have the boiling pointbelow the melting point of the compound being puried because solid meltsbefore dissolves $oiling out&. )n selecting a good recrystalli#ation solvent oneshould also consider ammability, toxicity, and expense.

)n selecting a solvent consider that like likes like. !olar compoundsdissolve polar compounds and non"polar compounds dissolve non"polarcompounds. he most commonly used recrystalli#ation solvents arepresented in able 2.3.

able 2.3 'ecyrstalli#ation solventsSo-6ent Form&-a po-arit Boi-in% point

78C9

water


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+ompounds with six or more carbons for each polar group will not bevery soluble in polar solvents but will be soluble in non"polar solvents suchas ben#ene and cyclohexane. )f a single solvent cannot be found that issuitable for recrystalli#ation, a solvent pair often used. he solvents must bemiscible in one another. ome commonly used solvent pairs are water"

ethanol, acetic acid 1 water, ether"acetone. ypically, the compound beingrecrystalli#ed will be more soluble in one solvent than the other. hecompound is dissolved in a minimum amount of the hot solvent in which it ismore soluble.(Source: Dr. Pahlavan. Recrystallization of Benzoic Acid)

he following formulas used in solubility problems.% lost in cold solvent5 $solubility in cold solvent6solubility in

hot solvent& x3% recovery of solid 5 7g $solid& 1 g $solid lost&8 x 3 6 g

$solid&

Exa!le: he solubility of solid 9:; in hot water $0.0 g63 ml at 3o

+& isnot very great, and its solubility in cold water $.02 g63ml at o+& issignicant. 1& H =aCl and traceo red dye, and 19& m0 o tap water in a beaer.


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bservations.

:ilter both crystals using a uchner unnel or suction fltration. ll crystalsmust be on the flter paper. 7emove the flter paper and place it on a watchglass4 and allow to dry overnight. "hen completely dry4 weight the crystals.Calculate the percentage yield o purifed crystals using the ormula.

H yield I ctual yield / 1&&Theoretical yield

;&e$tion$:

1. "hat is mother liAuor6__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. "hy must the fltration be carried out Auicly6__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. "hat must be considered in choosing a solvent or recrystalli?ation6__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

;. "hat is the relationship between the rate o cooling and si?e o crystals68/plain.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

9. "hat is the relation o surace contamination and occluded materials tosmall and large crystals6 8/plain.

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__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

(. @ive some reasons why suction fltration *vacuum, is to be preerred to

gravity fltration.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

B. (i


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2. "hat is meant by saying the two liAuids are JimmiscibleK6__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. Could alcohol be substituted or chloroorm in the above process6 "hy5"hy not6__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

;. "hy is it necessary to remove the stopper rom a separatory unnel whenliAuid is being drained rom it through a stopcoc6____________________________________________________________________________________________________________________________________________________________

______________________________________________________________________________

C. P&ri4!ation o So-i2$ , S&,-imation

%lace 1 gram o impure ben?oic acid contaminated with sodium chloride in aclean and dry ;&& m0 beaer. Then cover it by placing a :lorence or8rlenmeyer as hal flled with tap water.


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2. Lou want to puriy 1& g o Compound that has been contaminated with &.2 g o

Compound . )olubilities in water o the two compounds are given in the ollowing

table.

Compo&n2 So-&,i-it at+8= C 7%18 m(9

So-&,i-it at188=C 7%18 m(9

Compound &.&2G &.(D&

Compound &.22 (.(B

1. "hat volume o boiling water is needed to dissolve the 1& g o Compound 6

2.


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Experiment No. 0

SIMP(E DISTI((ATION


PRE'(AB:

1. "hat is distillation6 "hat two processes are involved in the distillationprocess6____________________________________________________________________________________________________________________________________________________________

______________________________________________________________________________

2. "hat ind o material can be separated by means o distillation6 @ive twoe/amples.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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8/amples$ a. __________________________ b. __________________________

II. OB)ECTI*ES:

ter completing this activity4 you should be able to$1. ssemble a distillation setup properly2. =ame the parts o the distillation setup3. @ive the unction o each part in the distillation setup;. @ive the importance o distillation process9. %erorm distillation

III. APPARATUS:

1 #istilling as 1 Thermometer

2 iron stand and ring 1 "ire gau?e3 clamps 1 adapter1 burner 1 unnel1 watch glass oiling chipsCors Condenser

I*. MATERIA(S:

%otassium permanganate9& H alcoholic solution

*. PROCEDURE:

1. )etFup a simple distillation apparatus.


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;&e$tion$.

ased on the results o your test or combustion4 which raction has the

higher ethanol content6 "hy6 8/plain the dierence in results.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


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2. +n the setFup4 where would the mercury bulb o the thermometer be6 "hy6________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. )hould a distilling as at the beginning o the distillation be flled to notmore than 253 its capacity and not to less than 153 its capacity6 "hy6________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

;. "hy is it dangerous to heat a compound in a distilling as assembly thatis closed tightly at every Noint and has no vent nor opening to theatmosphere6

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

9. "hat is the use o boiling chips in a distillation setup6 @ive one reasonwhy we cannot reuse boiling chips6________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

(. #raw the simple distillation setup and give the unction o each part.

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Experiment No. >STEAM DISTI((ATION OF ESSENTIA( OI(S


I. PRE'(AB:

1. "hat is steam distillation6__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. "hat characteristics must a substance possess or it to be separated roma heterogeneous mi/ture by steam distillation6__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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II. OB)ECTI*ES:

ter completing this activity4 you should be able to$1. ssemble a steam distillation setFup2. 0earn the unction o all its parts

3. Compare steam distillation with simple distillation as a separationmethod;. se steam distillation in the separation o slightly volatilesubstances rom those which are nonvolatile9. +solate essential oils rom resh plant material

III. APPARATUS:

1 #istilling as 1 Thermometer2 iron stand and ring 2 "ire gau?e

3 clamps 1 adapter2 burners 1 unnelCondenser oiling chipsCors )team generator)aety tube 7ound bottom as%latorm balance )eparatory unnel#ropper vial

I*. MATERIA(:

To be brought by students$ 29& g essential oil source

*. PROCEDURE:

A. STEAM DISTI((ATION*7eer to the fgure on steam distillation,

1. dd enough distilled water to the steam generator so that it is halFull.

2. :it a saety tube into the steam generator.

3. Cut the plant material into small pieces and get the weight. %lace the plantsample inside the distilling as up to twoFthirds ull. 7ecord the weight othe plant sample used or steam distillation.

;. 'i/ the sample with enough distilled water in the distilling as.

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9. ssemble the rest o the setup. Chec all connections or tightness. )howyour setup to your instructor or inspection beore starting the e/periment.

(.


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________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3.


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degree of purity can be made by comparing melting characteristicswith those of a pure sample.

/. he melting point helps to identify unknown samples, narrowing thenumber of possibilities, because a pure solid melts reproducibly

over a narrow range of temperatures.

3. The melting point helps to characteri?e and identiy newcompounds.

I. PRE'(AB:

1. #efne the ollowing terms$

1 a. melting point P

1 b. sublimation P

1 c. sintering P

1 d. eutectic mi/ture P

2. "hat is the eect o a small amount o impurity on the melting point o anorganic compound6____________________________________________________________________________________________________________________________________________________________

______________________________________________________________________________

II. OB)ECTI*E:

1. To determine and compare the melting points o ben?oic acid andben?oic acidFurea mi/ture

2. To determine the melting point o an unnown solid sample

III. APPARATUS:

Capillary tubes Thermometereaer with oil )tirring rod2 pc. 7ubber band

I*. MATERIA(S:

en?oic aciden?oic acidFurea mi/ture

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*. PROCEDURE

Fi--in% o Me-tin% Point Capi--arie$

1. %repare two capillaries *1 mm in diameter and ( cm in length,. )eal oneend o each capillary.

2. @rind a small pinch o pure ben?oic acid to a fne powder using mortar andpestle being careul not to contaminate the sample. +ntroduce the powderedsample into the capillary tube until it occupied about 2F3mm in height. %ushthe open end o the capillary into the powder and tap the closed end on thetable top.

3. btain another pinch o ben?oic acid and add a pinch o urea. %owder themi/ture using mortar and pestle4 and then introduce to the second capillary

tube. ttach the two capillaries to the thermometer as shown in :igure 1.

Determination o Me-tin% Point

1. :ill a dry beaer about 253 ull with coconut oil and rest the beaer on topo a wire gau?e on an iron ring.

2. )upport the thermometer frmly rom a ring stand by means o a clamp sothat the mercury bulb is dipped near the bottom o the beaer *about 1 cmrom the bottom,.


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Gigure ?.3. Helting !oint -pparatus

bservations.

Table (.1. 'elting points o pure ben?oic acid and ben?oic acidFurea mi/tureTheoretical '% range 8/perimental '% range

en?oic aciden?oic acidFureami/ture

;&e$tion:

Compare the observed melting points o ben?oic acid and ben?oic acidFureami/ture.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

#etermine the melting point range o an unnown solid given by yourinstructor. 7eer to Table (.2.

Table (.2. 'elting point data or the possible unnown samples.

S&,$tan!e Me-tin% Point 7oC9cetanilide 113.9F11;.&

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en?oic acid 121.9F122en?amide 12D.&F13&.&dipic acid 192.&F19;.&

)alicylic acid 19D.9F19G)uccinic acid 1D;.9F1D9.&

rea 132.&F13;.&/alic acid 1DG.&F1G1.&cetamide BD.&FD&.&

spirin 13D.&F1;&.&

nnown no. ______________________

'elting point range o unnown$ ______________________

+dentity o unnown$ ______________________

POST'(AB:

1. "hy should a solid be fnely divided powdered or use in a melting pointdetermination6__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. "hy should the oil bath should be continuously stirred during the

determination.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3.Lou and your lab partner tae melting points o the same sample. Lou observea melting point o GDF1&;MC4 while your partner observes a value o 1&BF1&GMC.8/plain how you can get two dierent values with e/actly the same sample.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

______________________________________________________________________________

;. :or a pure compound4 what can a high melting point or low melting pointindicate about its intermolecular orces o attraction6________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

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Experiment No. @

BOI(ING POINT DETERMINATION


he boiling point of a compound is the temperature at which itchanges from a liquid to a gas. Ioiling point is the temperature at which thevapor pressure of the liquid exactly equals the pressure exerted on it,causing the liquid to %boil% or change to the gas phase.

he molecules of compounds that exist in the liquid state are relatively

close together, compared with molecules of gaseous compounds. he closeproximity of molecules in the liquid state allow these molecules to interactvia non"covalent interactions $dipole"dipole, 4"bonding, van der


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liquid, the molecules begin to move away from each other by %breaking% thenon"covalent forces that hold the compound in the liquid state.

tructural features of a compound inuence the boiling point byincreasing or decreasing the moleculesJ ability to establish and maintain

non"covalent interactions that hold the molecules close together in the liquidstate. he structural features of a compound that inuence boiling point are(

$a& !olarity " )ncreased 4"bonds, polar covalent bonds or formal charges in amolecule tend to increase the boiling point. Hore polar elements in amolecule increase the total number of dipole"dipole, ion"dipole and6or 4"bonding interactions. Hore energy $higher boiling point temperature& isnecessary to break these interactions and allow the molecules to move awayfrom each other into a gaseous state.

$b& Holecular


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III. APPARATUS:

Capillary tubes Thermometereaer with oil )tirring rod

2 pc. 7ubber band +ron ring and standurner

I*. MATERIA(S:

#istilled waternnown liAuid sample

*. PROCEDURE

1. %lace 1F2m0 o distilled water in a vial.

2. The capillary tube was introduced into the vial with the open endimmersed in the liAuid sample.

3. ttach the vial to thermometer with a rubber band so that the liAuid isalongside the thermometer bulb4 and place the assembly into a clear oilbath. )ee :igure B.1.

;.


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Gigure .3( Ioiling !oint -pparatus

bservations.

'elting %oint range o water$

Trial 1$ _________________

Trial 2$ _________________

Table B.1. oiling point data or the possible unnown samples.

S&,$tan!e Me-tin% Point 7oC9Cyclohe/ane D18thyl acetate BBmyl acetate 1;G'ethyl alcohol (9

en?onitrile 1G&.B

en?aldehyde 1BD.18thyl alcohol BD.3B

+sopropyl alcohol D2.9niline 1D;.1

cetone 9(

nnown no. ______________________

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oiling point range o unnown$ ______________________

+dentity o unnown$ ______________________

+otes:

)f a piece of dark paper or other suitable material is placed behind the oil bath, it iseasier to see the bubbles coming from the capillary tube.

-s the liquid was being heated the air expanded in the inverted capillary. he liquidwas actually superheated when rapid bubbles emerged from the capillary but oncooling the point was reached at which the pressure inside the capillary matchedthe outside pressure. his is by denition, the boiling point.

POST'(AB:

1. "hich has a higher boiling point4 he/ane or pentanol6 "hy6________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. "hat eect *increase4 decrease4 no eect, would each o the ollowinghave on the observed boiling point range o the sample6 "hy6

a. 7apid heating________________________________________________________________________________________________________________________________________________

b. %oor circulation o the bath liAuid________________________________________________________________________________________________________________________________________________c. se o so much sample which e/tends considerably beyond the

thermometer________________________________________________________________________________________________________________________________________________

3. "ill the boiling point o a liAuid sample4 increase or decrease whencontaminated with$

a. !olatile impurity6 "hy6

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________________________________________________________________________________________________________________________________________________________________________________________________________________________

b. =onvolatile impurity6 "hy6

________________________________________________________________________________________________________________________________________________________________________________________________________________________

Experiment No. A(IP3ATIC 3DROCARBONS


I. PRE'(AB:

1. #raw structures o the ollowing compounds.

a. 24BFdimethyloctane

b. 243FdimethylF2Fbutene

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c. 14(Fheptadiene

d. cisF3Foctene

2. Classiy the compounds above as saturated or unsaturated hydrocarbon.

II. OB)ECTI*E:

To study some common properties o aliphatic hydrocarbons

III. APPARATUS:

cetylene generator

!ials!ial cors"atch glassTest tube holder

I*. MATERIA(S:

#rops o cyclohe/ane Cyclohe/ene1H potassium permanganate Calcium carbideromine water mmoniacal solution o cuprous

chloride

*. PROCEDURE:

A. PROPERTIES OF A(ANES CC(O3EANE

1. So-&,i-it an2 Den$it

%lace ; drops o cyclohe/ane in a vial and add 19 drops o water. #escribe itssolubility and its density with respect to water.

bservation.

8/planation.

+. F-amma,i-it

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%lace two drops o cyclohe/ane on a watch glass. +gnite with a matchstic."hat is the color o the ame6

8Auation.

/. Rea!tion it" Pota$$i&m Perman%anate

%lace 9 drops o a 1H solution o potassium permanganate to a vial and add9 drops cyclohe/ane. )hae the mi/ture and observe.

8Auation.

8/planation.

B. PROPERTIES OF A(ENES CC(O3EENE

%erorm all three tests done in %art using cyclohe/ene instead ocyclohe/ane. +nterpret and compare results. "rite your observations4eAuations and e/planations below.

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C. PROPERTIES OF A(NES ACET(ENE

,A-/0+:-cetylene is very combustible. Meep away all ames.

1. Preparation o A!et-ene

)et up a gas generator or the reaction between calcium carbide and water.%repare three test tubes with cors flled with water.


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+. Rea!tion it" Pota$$i&m Perman%anate

dd 9 drops o 1 H potassium permanganate in the test tube containing

acetylene gas. bserve. #escribe and interpret results.

bservation.

8Auation.

8/planation.

/. Rea!tion it" Bromine Water

dd 1 m0 bromine water to the second vial. )topper and shae. #escribe andinterpret results.

bservation.

8Auation.

8/planation.

0. Formation o !&pro&$ a!et-i2e

To the third vial4 add 9 m0 o ammoniacal solution o cuprous chloride until abrown precipitate is ormed.

bservation.

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8Auation.

e. P"$i!a- propertie$ o A!et-ene

=ote some common physical properties o acetylene such as odor4 color andsolubility with water.

POST'(AB:

1. "hy are aliphatic hydrocarbons generally insoluble in water6________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. "hat is the dierence in the reaction o cylohe/ane and cyclohe/ene

towards potassium permanganate solution6 8/plain.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. 'ention some saety precautions in the preparation o acetylene in thelab.____________________________________________________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________________________________________________

;. "rite a balanced chemical eAuation or the complete combustion oparaEn wa/ *C29


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Experiment No. HSTEREOC3EMISTR


7reer to $eparate "an2o&t9

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Experiment No. 18AROMATIC 3DROCARBONS


I. PRE'(AB:

1. #ierentiate aromatic rom aliphatic hydrocarbons________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. #raw the structures o the ollowing compounds.

a. mFchloronitroben?ene

b. 24;4(Ftribromoaniline

c. pFbromotoluene

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3. "hat is an o5p director6 "hat is a m director6

II. OB)ECTI*E:

To study some common physical and chemical properties o aromatichydrocarbons

III. APPARATUS:

%orcelain crucible !ialsurner 1&& m0 beaerThermometer

I*. MATERIA(S:

#rops o ben?ene Cyclohe/ane1 H -'n;*aintly pin, 1 m0 conc. =itric acid2 m0 conc. )uluric acid

*. PROCEDURE:

1. So-&,i-it

=ote some physical properties o ben?ene. Test the solubility o ; drops oben?ene in 19 drops o water. =ote its relative density relative to that owater.

"hat can be said about the solubility o ben?ene with water6 8/plain.

+. F-amma,i-it

+gnite 1 drop o ben?ene on a porcelain crucible. "rite your observations.7epeat the test with cyclohe/ane. Compare results.

8Auations.

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/. A!tion o Nitri! A!i2

+0E:


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POST'(AB:

1. side rom ben?ene4 give three other e/amples o aromatic compounds6Cite some o their usage6

a. ______________________________________________________________________________________________________________________________________________________________________________________________________

b. __________________________________________________________________

____________________________________________________________________________________________________________________________________

c. _____________________________________________________________________________________________________________________________________________________________________________________________________

2. "hat maes ben?ene a stable compound6

3. +s aniline an o5p or a m director6 "hat about nitroben?ene6

;. oth aniline and nitroben?ene are nitrogenFcontaining aromaticcompounds. "hy is one o5p directing and the other m6

9. "rite the mechanism o the reaction o nitration o ben?ene6

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Experiment No. 11A(CO3O(S AND P3ENO(S


I. PRE'(AB:

1. Concentration o alcohol is oten e/pressed as proo.


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____________________________________________________________________________________________________________________________________________________________

II. OB)ECTI*E:

To study some common physical and chemical properties o alcoholsand phenols

III. APPARATUS:

unsen burner !ials1&& ml eaer 'icrospatulaThermometer "ater bath

I*. MATERIA(S:

est for alcoholsCalcium carbide nhydrous copper *++, sulateG9 H ethyl alcohol +odine in -+3 drops o D = =a< solution 0ucas reagent8thyl alcohol +sopropyl alcoholTertFbutyl alcohol 1& H potassium dichromate#ilute suluric acid

est for !henols3 H sodium bicarbonate resorcinol1 H iron *+++, chloride salicylic acid2 H acetic acid solution 1Fbutanol&.1 H phenol solution

*. PROCEDURE:

A. A(CO3O(S

1. Io2oorm Te$t

To ; drops o ethyl alcohol in 1 m0 water4 add 3 drops o D = =a< solution4then dropwise a solution o iodine in -+ until a aint yellow color persists."arm the mi/ture in a water bath at about (& &C. )et aside or 9F1& minutes.

7epeat the test using isopropyl alcohol and tertFbutyl alcohol instead o ethylalcohol.

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bservations.

8Auation$

8/planation.

+. Oxi2ation

%ut 9 drops o each ethyl alcohol4 isopropyl alcohol4 tFbutyl alcohol in 3separate vials. To each add 9 drops o 1& H potassium dichromate and 9drops o dilute suluric acid solution. "arm in a water bath. =ote the color othe solutions. Compare the ease by which each o the alcohols is o/idi?ed.

bservations.

8Auations.

8/planation.

/. S&,$tit&tion Rea!tion

+nto three separate vials put 9 drops each o ethyl alcohol4 isopropyl alcoholand tFbutyl alcohol. dd an eAual amount o 0ucas reagent *QnCl2P


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8Auations.

8/planation.

POST'(AB:

1. lcohols are more soluble in water than hydrocarbons are in water. "hy6________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

2. "hy does the rule or solubility or alcohols depend upon their molecularsi?e6________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. "rite the structures and names o the isomeric 9Fcarbon saturatedalcohols.


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B. P3ENO(S

P"eno-$ are compounds that have the hydro/yl group attached to an aromaticring. Thus4 p"eno-is the specifc name or 9hydroxyben#ene;4 itselR FF and it isthe general name or the amily o compounds derived rom9hydroxyben#ene;. %ure phenol is a white crystalline solid4 mp ;2o.

,aution$ he solid, or concentrated solutions of phenol can cause painfulburns if allow to come into contact with the skin. )f spilled on the skin, it

should be removed at once with water and then with alcohol. hen, rubcotton that is wet with alcohol on the skin. 'epeat with dilute solution ofNa/+O2. Ginally, put a layer of ointment for burns on the a*ected skin.

1. T"e A!i2it o P"eno-$

-s a class, phenols are considered to be weak acids, and therefore, reactwith and dissolve in strong basesR like sodium hydroxide. 4owever, they donot dissolve in the weak base, sodium bicarbonate, Na4+O2.

Ar OH + NaHCO3 N.R.a weak basea weak acid

a weak acid

Ar OH + NaOH Ar O Na + H2Oa strong base

Test each o these compounds *phenol4 resorcinol4 salicylic acid4 ethyl alcohol,by adding small amount *about &.1g, to a ew drops o$

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*1, dilute =a


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8/planations.

/. Oxi2ation o P"eno-$

+n a small test tube place 9 drops o a &.9 percent aAueous potassiumpermanganate solution. dd an eAual volume o a 9 percent aAueoussolution o phenol. + necessary4 warm the solution in a hot water bath4 andshae it vigorously. "hat evidence is there that an o/idation has taenplace6

O,$er6ation$.

E


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Experiment No. 1+A(DE3DES AND ETONES

Name: Date:

Tea!"er$ Si%nat&re:

I. PRE'(AB:

1. "hat is the general ormula or an aldehyde6 etone6

2. "rite the structures o the ollowing compounds

a. 2Fmethylcyclopentanone

b. ;Fhe/enF2Fone

c. o P chloroben?aldehyde

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d. 2FmethylF3Fpentenal

II. OB)ECTI*E:

To study some common physical and chemical properties o aldehydesand etones

III. APPARATUS:

unsen burner !ials1&& m0 beaer Test tube holder3 test tubes Thermometer

I*. MATERIA(S:

#rops o$cetaldehyde en?aldehydecetone 1H -'n;24 ;Fdinitrophenylhydra?ine TollenKs reagent:ehlingKs :ehlingKs 3'


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B. C3EMICA( PROPERTIES

1. Rea!tion it" +J0 2initrop"en-"2ra5ine

dd 9 drops o the carbonyl compound to 9 drops o 24;Fdinitrophenylhydra?ine. )hae the mi/ture. =early all dinitrophenylhydra?ineprecipitate immediately but in ew cases they must be allowed to stand orabout 19 minutes.

bservation.

8/planation.

8Auations.

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+. Rea!tion it" To--en$ Rea%ent

dd 9 drops o the carbonyl compound to 9 drops o an ammoniacal solution

o silver nitrate or TollenKs reagent in a test tube. 'i/ thoroughly and heatgently in a water bath or 1& minutes. )et aside at least 1& minutes.

bservations.

8/planation.

8Auations.

/. Fe"-in%$ Te$t

+n a vial4 mi/ 9 drops o :ehlingKs solution and 9 drops o :ehlingKs solution

b. dd 9 drops o the carbonyl compound and warm in a water bath.

bservation.

8/planation.

8Auations.

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0. Bene2i!t$ te$t

%lace 1.& m0 o enedictKs solution to three separate tubes containing thecarbonyl compounds. %lace the test tubes in hot water bath.

bservation.

8/planation.

8Auations.

>. Io2oorm Te$t

To ; drops o the carbonyl compound in 1 m0 water4 add 3 drops o D = =a

chem 31 - laboratory manual

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