chemistry practicals class 12

8/12/2019 Chemistry practicals class 12

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Experiment-1

Aim-To analyse the given salt qualitatively and systematically.

Physical characteristics

1)Colour-White

2) Odour -Ammonical odour

3) State- Amorphous

4) Soluility- Soluble in cold distilled water

Preliminary dry heating test

Experiment Oservation !n"erence

Salt is taken in a dry test tube and

heated.

White fumes eole! white

sublimate on the cooler walls of the

test tube.

"ay be #$4%

Analysis o" Acidic radical

1) Salt is taken in perfectly dry test

tube and dilute $2S&4is added to it.

'risk efferescence obtained! when

pass throu(h lime water! it turn

milky but not turn potassium

dichromate (reen.

"ay be &32-

Con"irmatory test

Salt is taken in a test tube and

"(S&4is added to it.

White precipitate. &32- confirmed.

Analysis o" #asic radical

1) Salt solution is taken in attest tube

and #a&$ is added to it.Warm the test tube.

White fumes with ammonical odour

comes out which turns dense onbrin(in( a (lass rod dipped in dilute

$l solution.

"ay be #$4%

2) *o the salt solution! #essler+s

rea(ent is added.

,eddish brown precipitate obtained. #$4% confirmed.

$esult- Salt is Ammonium carbonate

Acidic radical- &32-

#asic radical-#$4%


2/32

Experiment-%



1)Colour-White2) Odour -Ammonical odour

3) State- Amorphous

4) Soluility- Soluble in cold distilled waterPreliminary dry heating test



heated.

White fumes eole!white sublimate

on the cooler walls of the test tube

"ay be #$4%


1) Salt is taken in perfectly dry testtube and dilute $2S&4is added to it.

#o reaction. &32- ! S2-! S&3

2-! #&2absent

2) Salt is taken in a dry test tube and

conc. $2S&4is added to it and

heated.

#o chan(e. l- ! 'r-! -! #&3-! $3&&

-absent

&' Ammonium molydate test-

*o the a/ueous solution of salt few

drops of conc $#&3 is added and

solution is boiled. Add ammoniummolybdate solution to it.

0eep yellow precipitate obtained. &43-obtained.

(' )agnesia mixture test-

*o the salt solution! ma(nesia

miture is added and the solution is

boiled and allowed to stand. Solid

#$4l is added to "(l2solution!

boiled! cooled and #$4&$ is added

to it).

White precipitate obtained. &43-obtained.


1) Salt solution is taken in attest tube

and #a&$ is added to it.

Warm the test tube.

White fumes with ammonical odour

comes out which turn dense on

brin(in( a (lass rod dipped in dilute

$l solution.

"ay be #$4%


rea(ent is added.

,eddish brown precipitate obtained. #$4% confirmed.

$esult- Salt is Ammonium phosphate

Acidic radical- &43- #asic radical-#$4

%


3/32

Experiment-&



1) Colour-White

2) Odour ine(ar like odour3)State- rystalline




heated.

White fumes eole with ine(ar

like smell.

"ay be $3&&-




#o reaction. &32- ! S2-! S&3

2-! #&2absent



heated.Con"irmatory test

1) Salt is taken in a watch (lass and

mied with solid oalic acid and

pate is prepared.2) Salt solution is taken and 5el3

solution is added to it.

0iide filtrate into two parts6

a) *o the first part! $l is added

followed by water.

b) *o the second part distilled water

is added and boiled.

White fumes eoled with ine(ar

like smell.

ine(ar like smell

,ed coloured filtrate obtained.

,ed colour disappears.

,eddish brown precipitate obtained.

"ay be $3&&-

$3&&- confirmed.

$3&&- confirmed.

$3&&- confirmed.



rea(ent is added.

#o ,eddish brown precipitate

obtained.

#$4% absent.

2) *o the salt solution! dilute $l is

added.

White precipitate obtained. b2%confirmed.

3) recipiate obtained is centrifu(ed

and dissoled in distilled water and

boiled.

a) ontents were allowed to cooland kept undisturbed.

White precipitate reappears. b2%confirmed.

b) *o the second part potassiumchromate solution is added.

c) *o the third part! otassium

iodide solution is added.

7ellow precipitate obtained whichdissoles in #ao$ solution.

7ellow precipitate obtained.

b2%

confirmed.

b2%confirmed.

$esult- Salt is lead acetate

Acidic radical- $3&&- #asic radical- b2%


4/32

Experiment-(



1) Colour-'lue

2) Odour &dourless3)State- rystalline




heated.

White fumes eole! water droplets

are seen on the inner cooler walls of

the test tube.

"ay be l-




#o reaction. &32- ! S2-! S&3

2-! #&2absent



heated.

Con"irmatory test

1) *ake salt in a test tube and solid

82r2&9is added followed by conc.

$2S&4and the miture is heated.

*o the yellow solution! acetic acid

alon( with lead acetate solution is

added.

2) *o the salt solution few drops of$#&3 is added followed by siler

nitrate solution.

White fumes eoled which become

dense on brin(in( a (lass rod dipped

in #$4&$ solution.

,ed fumes of chromyl chloride

comes out. &n passin( throu(h

#a&$ solution! it turns yellow.


White precipitate obtained which iscompletely soluble in #$4&$

solution.

"ay be l-

l- confirmed.

l- confirmed.

l- confirmed.



rea(ent is added.


obtained.

#$4% absent.


added.

#o white precipitate obtained. :roup 1 absent

3) ass $2S (as throu(h the aboe

solution.

'lack precipitate obtained. :roup 2 present.

4) 0issole precipitate in dilute$#&3and boil to epel out $2S (as.

Small /uantity of solution is taken

and dilute $2S&4and 2$;&$ isadded.

#o white precipitate obtained. b2%

absent.

;) *o the other part of solution!

#$4&$ is added in ecess and

solution is diided into two parts.

a) *o part 1! acetic acid and

potassium ferrocyanide solution is hocolate brown precipitate u2%confirmed.


5/32

added.

b) *o part2! few drops of acetic acid

and potassium iodide solution is

added.

obtained.

White precipitate in brown colour

solution obtained. u2%confirmed.

$esult- Salt is copper) chloride

Acidic radical- l-

#asic radical- u2%


6/32

Experiment-*



1) Colour-White





heated.

'rown fumes eole and colour of

residue is brown.

"ay be 'r- or #&3-




#o reaction. &32- ! S2-! S&3

2-! #&2absent



heated.

Add copper turnin(s to the test tube.

Con"irmatory test

3) Add freshly prepared 5eS&4

solution to the salt solution and thenconc. $2S&4is added alon( the walls

of the test tube.

4) +iphenylamine test

Add few drops of diphenylamine to

the salt solution.

,eddish brown fumes with pun(ent

smell are obtained.

'rown fumes become dense.

'rown rin( is obtained.

0eep blue colour obtained.

"ay be 'r- or #&3-

#&3- confirmed.

#&3- confirmed.

#&3- confirmed.



rea(ent is added.


obtained.

#$4% absent.


added.



solution.

7ellow precipitate obtained. :roup 2 present.

4) 0issole precipitate in conc.

$#&3and boil to epel out $2S (as

and diide into two parts6

a) *o part 1! ammonium molybdatesolution is added.

b) *o part 2! few drops of #$4&$ is

added followed by ma(nesia

miture.


White precipitate obtained.

As3%

confirmed.

As3%confirmed.

$esult- Salt is Arsenic nitrate Acidic radical-#&3- #asic radical- As3%


7/32

Experiment-,



1) Colour-White

2) Odour &dourless3)State- Amorphous




heated.

White fumes eole with water

droplets on inner cooler walls of the

test tube.

"ay be l-




#o reaction. &32- ! S2-! S&3

2-! #&2absent



heated.

Con"irmatory test




*o the yellow solution! acetic acid


added.

4) *o the salt solution few drops of$#&3is added followed by siler

nitrate solution.



in #$4&$ solution.


come out. &n passin( throu(h



White precipitate obtained which iscompletely soluble in #$4&$

solution

"ay be l-

l- confirmed.

l- confirmed.

l- confirmed.



rea(ent is added.


obtained.

#$4% absent.


added.



solution.

#o precipitate obtained. :roup 2 absent.


$#&3and boil to epel out $2S

(as.*hen solid ammonium chloride

is added followed by #$4&$ in

ecess.

:elatinous white precipitate

obtained.

:roup 3 present.

"ay be Al3%

;) ae test

0issole white precipitate in dilute$l. *o it one drop blue litmus

solution is added. *hen #$4&$ is

'lue precipitate floatin( incolourless solution obtained which

(ies appearance of a blue lake.

Al3% confirmed.


8/32

added dropwise till blue colour

disappears.

$esult- Salt is Aluminium chloride

Acidic radical- l-

#asic radical- Al3%


9/32

Experiment-/



1) Colour-White

2) Odour &dourless3)State- Amorphous




heated.



test tube.

"ay be


10/32

9) 0iide the solution in two parts6

a) Add #a&$ to the first part.

b) Add potassium ferrocyanide to thesecond part.

White precipitate obtained which

dissoles in ecess of #a&$.

'luish white precipitate obtained.


11/32

Experiment-0



1) Colour-:reen





heated.



test tube.

"ay be S&42-




#o reaction. &32- ! S2-! S&3

2-! #&2absent



heated.

Con"irmatory test "or SO(%-

3) *o the salt solution add dilute

$l followed by few drops of 'al2

solution.

4) *o the salt solution add few drops

of acetic acid and then lead acetate is

added.

#o chan(e.

White precipitate obtained which are

insoluble in conc $l


insoluble in hot ammonium acetate

solution.

l- ! 'r-! -! #&3-! $3&&

-absent

S&42- confirmed.

S&42- confirmed.



rea(ent is added.


obtained.

#$4% absent.


added.



solution.



$#&3and boil to epel out $2S(as.*hen solid ammonium chloride

is added followed by #$4&$ in

ecess.


;) *hrou(h the aboe solution $2S

(as is passed.

&bsered the colour of the ori(inalsalt. Since it is (reenish! perform

confirmatory test for #i2% with the

ori(inal solution.


"ay be #i2% oro2%


12/32

=) *o one part of the ori(inal

solution! #$4&$ solution and few

drops of dimethyl (lyoime is

added.

'ri(ht rose red precipitate obtained. #i2%confirmed.

9) *o another part #a&$ in ecess)and bromine water is added and

boiled.

'lack precipitate of #i&$)3isobtained

#i2%obtained.

$esult- Salt is #ickel sulphate

Acidic radical-S&42-

#asic radical-#i2%


13/32

Experiment-


Physical characteristics1) Colour-ink

2) Odour &dourless

3)State- rystalline4) Soluility- Soluble in cold distilled water

Preliminary dry heating test



heated.



test tube.

"ay be S&42-




#o reaction. &32- ! S2-! S&3

2-! #&2absent

2) Salt is taken in a dry test tube andconc. $2S&4is added to it and

heated.

Add copper turnin(s to the test tube.Con"irmatory test


solution to the salt solution and then

conc. $2S&4is added alon( the walls

of the test tube.

4) +iphenylamine testAdd few drops of diphenylamine tothe salt solution.

,eddish brown fumes with pun(entsmell are obtained.




"ay be 'r- or #&3-

#&3- confirmed.

#&3- confirmed.

#&3- confirmed.



rea(ent is added.


obtained.

#$4% absent.


added.


3) ass $2S (as throu(h the aboesolution. #o precipitate obtained. :roup 2 absent.


$#&3and boil to epel out $2S

(as.*hen solid ammonium chloride

is added followed by #$4&$ inecess.



(as is passed.

&bsered the colour of the ori(inal


"ay be #i2% oro2%


14/32

salt. Since it is pink! perform

confirmatory test for o2% with the

ori(inal solution.

=) *o one part of the ori(inal

solution! #$4&$ is added toneutrali>e the solution. Add acetic

acid and a crytal of potassium nitriteand warm the contents.

7ellow precipitate obtained. o2%confirmed.

9) *o another part of ori(inal

solution! add 1 ml of ether and a

crytal of ammonium thiocyanate.

Shake and allowed to settle.

'lue colour in ethereal layer o2%obtained.

$esult- Salt is obalt nitrate

Acidic radical-#&3-

#asic radical- o2%


15/32

Experiment-12



1) Colour-ale pink





heated.

olour of fumes is white and yellow

residue obtained.

"ay be S&42-




#o reaction. &32- ! S2-! S&3

2-! #&2absent



heated.

Con"irmatory test "or SO(%-

3) *o the salt solution add dilute

$l followed by few drops of 'al2

solution.

4) *o the salt solution add few drops

of acetic acid and then lead acetate is

added.

#o reaction.


insoluble in conc $l


insoluble in hot ammonium acetate

solution.

l- ! 'r-! -! #&3-! $3&&

-absent

S&42- confirmed.

S&42- confirmed.



rea(ent is added.


obtained.

#$4% absent.

2) *o the salt solution! dilute $l isadded.


3) ass $2S (as throu(h the aboesolution.


4) 0issole precipitate in conc.$#&3and boil to epel out $2S

(as.*hen solid ammonium chlorideis added followed by #$4&$ in

ecess.



(as is passed.

'uff coloured precipitate obtained. :roup 4 present.

"ay be "n2%


16/32

=) 0issole the precipitate in dilute

$l and boil the solution to epel

out $2S (as. 0iide the solution in

two parts6

a) *o the aboe solution #a&$ isadded and shaken.

b) *he aboe black?brown

precipitate is collected. onc $#&3

and lead peroide is added to it.is

then boiled! cooled and allowed to

cool.

White precipitate is obtained whichturns black?brown on addition of

bromine water.

ink coloured solution is obtained.

"n2%confirmed.

"n2%confirmed.

$esult- Salt is "an(anese sulphate

Acidic radical-S&42-

#asic radical- "n2%


17/32

Experiment-11



1) Colour-White





heated.

White fumes eoled.

olour of residue

$ot-white

old-White

"ay be l-




#o reaction. &32- ! S2-! S&32-! #&2absent



heated.

Con"irmatory test




*o the yellow solution ! acetic acid


added.2) *o the salt solution few drops of

$#&3is added followed by silernitrate solution.



in #$4&$ solution.





White precipitate obtained which is

completely soluble in #$4&$solution.

"ay be l-

l- confirmed.

l- confirmed.

l- confirmed.



rea(ent is added.


obtained.

#$4% absent.


added.



solution.



$#&3and boil to epel out $2S (as.

*hen solid ammonium chloride is

added followed by #$4&$ inecess.



18/32


(as is passed.


=) Solid #$4l is then added and

dissoled and the solution is boiled

and cooled followed by the addition

of #$4&$ in ecess. #$4)2&3

solution is then added.

White precipitate obtained. :roup ; present.

9) 0issole the white precipitate in

hot dilute acetic acid and diide the

solution into two parts6a) *o one part of the aboe solution

ammonium oalate solution is then

added followed by #$4&$ solution.

b) 3lame test-

0ip platinum wire in a paste of the

salt and conc. $l and introduced

into the flame.

White precipitate confirmed.

'rick red colour is imparted to the

flame.

a2%confirmed.

a2%confirmed.

$esult- Salt is calcium chloride

Acidic radical-l-

#asic radical- a2%


19/32

Experiment-1%



1) Colour-White





heated.

White fumes eoled.

olour of residue

$ot-white

old-White

"ay be l-







heated.

Con"irmatory test




*o the yellow solution ! acetic acid


added.2) *o the salt solution few drops of

$#&3is added followed by silernitrate solution.



in #$4&$ solution.





White precipitate obtained which is

completely soluble in #$4&$solution.

"ay be l-

l- confirmed.

l- confirmed.

l- confirmed.



rea(ent is added.


obtained.

#$4% absent.


added.



solution.





added followed by #$4&$ inecess.



20/32


(as is passed.





of #$4&$ in ecess. #$4)2&3




hot dilute acetic acid and diide the

solution into two parts6a) *o one part of the aboe solution!

few drops of potassium chromate

solution is added.

b) 3lame test-

0ip platinum wire in a paste of the

salt and conc. $l and introduced

into the flame.

7ellow precipitate confirmed.

:rassy (reen colour is imparted to

the flame.

'a2%confirmed.

'a2%confirmed.

$esult- Salt is 'arium chloride

Acidic radical-l-

#asic radical- 'a2%


21/32

Experiment-1&



1) Colour-White





heated.

,eddish brown (as eoles.

olour of residue

$ot-white

old-7ellowish

"ay be 'r- or #&3-







heated.Add copper turnin(s to the test tube.

Con"irmatory test




of the test tube.


Add few drops of diphenylamine tothe salt solution.


smell are obtained.




"ay be 'r- or #&3-

#&3- confirmed.

#&3- confirmed.

#&3- confirmed.



rea(ent is added.


obtained.

#$4% absent.


added.



solution.





added followed by #$4&$ in

ecess.


;) *hrou(h the aboe solution $2S(as is passed.



22/32




of #$4&$ in ecess. #$4)2&3




hot dilute acetic acid and diide thesolution into two parts6

a) *o one part of the aboe solution!

few drops of ammonium sulphate

solution is added.

b) 3lame test-

0ip platinum wire in a paste of thesalt and conc. $l and introduced

into the flame.

White precipitate confirmed.

rimson red colour is imparted tothe flame.

Sr2%confirmed.

Sr2%confirmed.

$esult- Salt is Strontium nitrate

Acidic radical-#&3-

#asic radical- Sr2%


23/32

Experiment-1(



1) Colour-White





heated.

,eddish brown (as eoles.

olour of residue

$ot-white

old-7ellowish

"ay be 'r- or #&3-







heated.Add copper turnin(s to the test tube.

Con"irmatory test




of the test tube.


Add few drops of diphenylamine tothe salt solution.


smell are obtained.




"ay be 'r- or #&3-

#&3- confirmed.

#&3- confirmed.

#&3- confirmed.



rea(ent is added.


obtained.

#$4% absent.


added.



solution.





added followed by #$4&$ in

ecess.


;) *hrou(h the aboe solution $2S(as is passed.



24/32




of #$4&$ in ecess. #$4)2&3


#o white precipitate obtained. :roup ; absent.

9) *o the ori(inal solution! add a

pinch of #$4

l! a few drops of#$4&$ and ecess of aammonium

phosphate solution and scratch the

sides of the test tube with a (lass

rod.

White precipitate obtained. :roup = present.

"(

2%

confirmed.

$esult- Salt is "a(nesium nitrate

Acidic radical-#&3-

#asic radical- "(2%


25/32

Experiment-1*

Aim- *o analyse the functional (roup present in the (ien or(anic compound. Alcohol)

Aim- *o analyse the functional (roup present in the (ien or(anic compound. henol)

1) Sodium metal test-

*o 1ml of or(anic compound! asmall piece of sodium metal is

added.

'risk efferescence comes out dueto eolution of $ydro(en (as.

Alcoholic (roup present.

2)Ester test-

Add 1 ml of acetic acid to or(anic

compound taken in a test tube

followed by 4-; drops of conc.

$2S&4. ontents are heated on a

water bath for 1@ minutes and

emptied in a beaker containin( one

test tube water

5ormation of fruity smellin(

substance called ester.


3) Ceric ammonium nitrate test-

*o 1ml of or(anic compound taken

in a test tube! few drops of ericammonium nitrate btained.is added.

ink or red colour obtained. Alcoholic (roup present.

4) !odo"orm test-

*o 1ml of compound ! 1 solid

iodine is dissoled and #a&$

solution is added dropwise untilbrown colour of iodine is dischar(ed

and contents are warmed on a water

bath and cooled.

5ormation of yellow precipitate

obtained.


;) Acetyl chloride test-

*o 2ml of compound taken in a test

tube! 2-3 drops of acetyl chloride is

added and a (lass rod dipped in

#$4&$ solution is brou(ht near themouth of the test tube.

Bolution of white fumes. Alcoholic (roup present.


26/32

E4PE$!)E5T O#SE$6AT!O5 !53E$E5CE

1) itmus test-

*o a drop of compound blue litmus

is added.

'lue litmus turns red. Acidic (roup. "ay be phenol.

2)5eutral 3erric chloride test-

*o the or(anic compound neutral

5el3

solution is added.

iolet colourtion obtained. henolic (roup present.

3) iermann7s test-

2-3 crystals of #a#&2are taken in a

test tube and or(anic compound is

added to it. ontents are heated

(ently on a water bath for 1minute

and allowed to cool. 1ml of conc.$2S&4is then added and shaken.

0eep blue colouration obtained.

olour chan(es to red when water is

added. t chan(es back to blue?(reen

on addition of #a&$ solution.

henolic (roup present.

Aim- *o analyse the functional (roup present in the (ien or(anic compound. Aldehyde)


1) %8( 9+initrophenyl hydra:ine test

*o the or(anic compound dissoled in

thanol! 2 ml of 2!4-0#p solution is

added.orked the test tube and shake it

and allowed to stand for ; minutes.

5ormation of yellow-oran(e

precipitate.

ndicates the presence of carbonyl

(roup.

2) Sodium isulphite test-

*o the or(anic compound! #a$S&3solution is added. *est tube is corked!

shaken and left to stand for 2@ minutes.

5ormation of crystalline whiteprecipitate takes place..

ndicates the presence of carbonyl(roup.

3) Schi""7s test-

*o the or(anic compound! 1 ml of

Schiff+s rea(ent is added.

ink? ,ed? "a(enta colour

obtained.

Aldehydic (roup present.

4) Tollen7s test-*o siler nitrate solution! 2-3 ml of

dilute #a&$ is added which results inthe formation of a brown precipitate.

#$4&$ is then added till brownprecipitate disappears. *o the aboe

li/uid! or(anic compound is added and

miture is heated on a water bath for C-

1@ minutes.

;) 3ehling7s test-

n two test tubes! 5ehlin( A and ' are

taken respectiely and then mied. *o

this solution ! or(anic compound is

added and contents are heated on awater bath.

Shinin( siler mirror obtained.

,ed precipitate of u2& obtained.



Aim- *o analyse the functional (roup present in the (ien or(anic compound. 8etone)


27/32


28/32


1) Soluility test-

*o the or(anic compound! dilute

$l is added and shaken.

ompound is soluble in dilute $l. "ay be amine.

1) itmus test-

*o a drop of compound red litmus

solution is added.

,ed litmus turns blue. 'asic (roup. "ay be amine.

3) Carylamine test-

*o the solid 8&$ pellets taken in a

test tube about 1ml of of ethanol is

added and the contents are warmed!

followed by addition of chloroform

and (ien or(anic compound.

Dnpleasant odour of carbuylamine

obtained.

rimary amine present.

4) 5itrous acid test-

0issole the or(anic compound in 1

ml of conc. $l and cooled the

contents in a ice bath. n another test

tube! a solution of sodium nitrite is

made and kept in ice for coolin(.

"ied the contents of both the test

tubes.

'ubbles of nitro(en (as obtained. rimary amine present.

;) A:o dye test-

0issole or(anic compound in 1 ml

of conc. $l and kept for coolin( in

ice bath. n 2ndtest tube! an a/ueous

solution of #a#&2 is prepared and

cooled. n the 3rdtest tube E-

naphthol is taken and cooled in ice

bath. "i all the contents of the

respectie solutions.

&ran(e red precipitate obtained. rimary aromatic amine present.

Experiment-1,


29/32

Aim- *o analyse the food stuff carbohydrate) present in the (ien sample.


1) )olisch7s test-

*o an a/ueous sample of the food!

"olisch+s rea(ent 1@ alcoholic

solution of F-naphthol) is added. 1mlof conc. $2S&4is then added

dropwise throu(h the walls of the

test tube.

urple rin( is produced at the

Gunction of the two layers.

arbohydrate confirmed.

2)3ehling7s test-

"i e/ual amount of 5ehlin( A and

' in a test tube. *o this solution food

sample is added and the contents are

heated on a water bath.

,ed precipitate of u2& is obtained. ndicates the presence of a reducin(

su(ar.

3)#enedict7s test-

*o the a/ueous solution of food

sample! 'enedict+s rea(ent is added

and test tube is heated on a water

bath.

,ed precipitate of u2& is obtained. ndicates the presence of a reducin(

su(ar.

4) Tollen7s test-

*o siler nitrate solution! 2-3 ml of

dilute #a&$ is added which results

in the formation of a brown

precipitate. #$4&$ is then added till

brown precipitate disappears. *o the

aboe li/uid! food sample is added

and miture is heated on a waterbath for C-1@ minutes.

Shinin( siler mirror obtained. ndicates the presence of a reducin(

su(ar.

*o analyse the food stuff oils?fats) present in the (ien sample.


1) Soluility test-

5ood sample solution is taken in 3

test tubes. *o the first test tube water

is added. *o the second ethanol is

added and to the third chloroform is

added. Bach test tube is shaken

i(orously aand obsered carefully.

a) mmiscible in water

b) n alcohol it forms lower layer

which dissoles on heatin(.

c) "iscible in choloroform.

&il?5at is confirmed.

2) Translucent spot test-

A drop of (ien food sample is takenon the filter paper which is folded

and pressed a little.

&n unfoldin( a translucent or (reasyspot is obtained. &il?5at is confirmed.

3)Acrolein test-

5ood sample is heated with crystals

of 8$S&4in atest tube.

un(ent irritatin( odour of acrolein

is obtained.

&il?5at is confirmed.

Aim- *o analyse the food stuff proteins) present in the (ien sample.


30/32


1)#iuret test-

*o the dispersion of food sample! 2

ml of #a&$ solution is added

followed by 4-; drops of 1 uS&4solution.

'luish iolet colouration obtained rotein confirmed.

2)4anthoproteic test-

*o 2 ml of dispersion of $#&3is

added and contents are heated on a

water bath.

7ellow coa(ulum obtained. rotein confirmed.

3))illion7s test-

*o the dispersion of the (ien foodsample! "illion+s rea(ent is added.

White precipitate of obtained whichchan(es to brick red on boilin(.

rotein confirmed.

4) 5inhydrin test-

*o the dispersion of the (ien

protein! #inhydrin solution is added

and the contents are boiled.

ntense blue colouration obtained. rotein confirmed.

Experiment-1/


31/32

Aim- *o prepare crystals of 5errous ammonium sulphate "ohr+s salt)Theory- "ohr+s salt is prepared by dissolin( an e/uimolar miture of hydrated ferrous sulphate and ammonium

sulphate in water containin( a little sulphuric acid and then subGectin( the resultin( solution to crytallisation when

pale (reen coloured crystals of ferrous ammonium sulphate hain( monoclinic shape separates out.

5eS&4.9 $2& % #$4)2S&4 5eS&4. #$4)2S&4.= $2& % $2&

)aterials required- *wo beakers 2;@ml) ! hina dish! funnel! funnel stand! (lass rod! wash bottle ! tripod stand!

filter paper! ferrous sulphate crystals! ammonium sulphate crystals! dilute sulphuric acid! distilled water.

Procedure

1) *ake a 2;@ ml beaker and wash it with water. *ransfer 9 ( of ferrous sulphate and 3.; ( of ammonium sulphate

crystals to it. Add about 2-3 ml of dilute sulphuric acid to preent the hydrolysis of ferrous sulphate.2) n another beaker boil about 2@ ml of water for about ; minutes to epel dissoled air.

3) Add the boilin( hot water to the contents in the first beaker in small installments at a time. Stir with a (lass rod

until the salts hae completely dissoled.

4) 5ilter the solution to remoe undissoled impurities and transfer the filtrate to a china dish.

;) $eat the solution in the china dish for some time to concentrate it to the crytallisation point.

=) lace the china dish containin( saturated solution oer a beaker full of cold water. &n coolin( crystals of "ohr+s

salt separate out.

9) decant off the mother li/uor /uickly. Wash the crystals in the china dish with a small /uantity of alcohol toremoe nay sulphuric acid stickin( to the crystals.

C) 0ry the crystals by placin( them between filter paper pads.

Oservations-

Wei(ht of crystal obtained-

Bpected yield of crystals-

olour of the crystals- Hi(ht (reen

Shape of the crystals- "onoclinic

Precautions-

1) *o aoid oidation of ferrous sulphate boiled water is to be added.

2) 0ilute sulphuric acid is added immediately to preent hydrolyis of 5eS&4

3) 0o not heat the solution for a lon( time as it may oidi>e ferrous ions to ferric ions.

Experiment-10


32/32

Aim-*o prepare a sample of 0iben>al acetone.

Theory- *he preparation of diben>al acetone is an eample of laisen- Schmidt reaction. *his reaction takes place

between aromatic aldehyde and aliphatic ketones in presence of sodiumhydroide. *wo moles of ben>aldehyde

condense with one mole of acetone to (ie diben>al acetone.

2 $& % $3&$3 #a&$ $I$&$I$

Apparatus and chemicals required

2.; ml ben>ldehyde!1 ml acetone!;ml #a&$ 1@)! 2; ml rectified spirit!1@@ ml conical flask! 2;@ ml beaker! test

tube! funnel

Procedure

1) *ake a conical flask 1@@ml) and add. 2.; ml ben>aldehyde! 1 ml of acetone and 2; ml of methylated spirit. ork

the flask and shake to obtain a clear solution.

2) *ake ;ml of 1@ #a&$ solution in a test tube and add this to conical flask drop by drop with shakin( of the

flask. "aintain the temperature of th reaction miture between 2@-2;o durin( addition of sodium hydroide

solution.3) ork the flask a(ain and shake i(orously for about 1@ minutes! releasin( pressure from time to time.

4) Allow it to stand for about 2@ minutes at room temperature and then cool in ice water for a few minutes.

;) 5ilter the yellow coloured solid and wash it with water to remoe traces of alkali.

=) ,ecrystallisation of diben>al acetone.

0issole the aboe yellow coloured crude solid in minimum amount of hot rectified spirit and then allowin( it to

cool slowly. ale yellow crystals of diben>al acetone separate out. 5ilter the crystals and dry. Wei(h aand record its

yield.

$esult7ield of diben>al acetoneI

Bpected yield of diben>al acetoneI 1.; (

Precautions

1) Add #a&$ dropwise to the reaction miture with constant shakin( of the flask.

2) Wash the precipitate with water to remoe traces of #a&$ stickin( to them.

3) Dse minimum amount of rectified spirit to dissole crude sample for crystalli>ation.

chemistry practicals class 12

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