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CHEM LAB
Exam Tips 2.ppt
SODIUM FUSION(LASSAIGNES) TEST

THE ORGANIC COMPOUND TO BE
TESTED IS FUSED WITH METALLIC
SODIUM.IN THIS WAY SODIUM
CYANIDE,SODIUM SULPHIDE AND/OR
SODIUM HALIDES IS FORMED WHICH
CAN BE READILY IDENTIFIED.
TEST FOR NITROGEN



THE CYANIDE FORMED CAN BE
DETECTED BY PRUSSIAN BLUE TEST.
STEP 1: FESO4 +
6NACN=Na4[Fe(CN)6]+Na2SO4
STEP 2: 3Na4[Fe(CN)6] +
2Fe2(SO4)3=Fe4[Fe(CN)6]3(PRUSSIAN
BLUE)+6Na2SO4
TEST FOR SULPHUR
THIS IS TESTED AS SULPHIDE
 TEST 1:
THE COMPOUND IS TREATED WITH DIL. ACETIC ACID AND
THEN WITH LEAD ACETATE.
A BLACK PRECEPATE OF LEAD ACETATE INDICATES THE
PRESENCE OF SULPHUR

TEST 2:
THE COMPOPUND IS TREATED WITH DIL.SOLN. OF
Na2[Fe(CN)5NO] A PURPLE COLOURED COMP. OF
Na4[Fe(CN)5NOS] IS FORMED INDICATING THE
PRESENCE OF SULPHUR.
TEST FOR HALOGENS
COLOUR
THE FUSION SOLN IS
ACIDIFIED WITH
DIL.HNO3 AND THEN
WHITE
EXCESS OF AgNO3 IS
ADDED.
SOLUBILITY
IN Aq.
Ammonia
HALO
GEN
COMPLETEL Cl
Y SOLUBLE
PALE
YELLOW
PARTIAL
SOL.
YELLOW
IN SOLUBLE.
Br
I
_OH (ALCOHOLIC)
TEST 1::SODIUM TEST
 2ROH+2Na=2RONa+H2(GAS)
 TEST 2:: ACETYL CHLORIDE TEST
acetyl chloride reacts vigorously with primary
and secondary alcohols with evolution of
HCl.
HCl +NH4OH =NH4Cl(WHITE FUMES)+ H2O

PHENOL
GIVES VIOLET COLOUR WITH FeCl3
SOLN.
FeCl3+6C6H5OH= [Fe(OC6H5)6]-3+3HCl

CARBONYL TEST

FOR ALDEHYDES AND KETONES.
2,4-DINITROPHENYL HYDRAZINE-TEST
-> FORMATION OF CRYSTALLINE PRECIPITATE
WITH THE REAGENT INDICATES THE PRESENCE
OF ALDEHYDES AND KETONES.
SPECIFIC FOR ALDEHYDES
SCHIFF’S TEST
->APPEARANCE OF PINK RED OR
MAGENTA COLOR WITH REAGENT.

TOLLEN’S TEST ->SILVER MIRROR WITH
REAGENT(Ag+).
FEHLING’S TEST ->RED PRECIPITATE OF
Cu2O WITH ALDEHYDE GROUP.
CARBOXYLIC GROUP



LITMUS TEST (BLUE TO RED).
SODIUM BICARBONATE
TEST(NaHCO3).CO2 MOVES OUT FROM
NaHCO3.
ESTER TEST: REACTS WITH ALCOHOL TO
GIVE SWEET SMELLING
COMPOUND(ESTER).
ALIPHATIC AMINO GROUP



WITH HNO2 PRIMARY GROUP GIVES
ALCOHOL
WITH HNO2 SEC GIVES NITROSOAMINES
YELLOW OILY LIQUID(R2N-NO).
WITH HNO2 TERTIARY GROUP GIVES
TRIALKYLAMMONIUM NITRITE (R3 N+
HONO-)
AROMATIC AMINES



WITH HNO2 PRIMARY GIVES BENZENE
DIAZONIUM CHLORIDES(PhN2+ Cl-).
SECONDARY GROUP GIVES N-ALKYL-NPHENYL NITROSOAMINE.
TERTIARY GROUP GIVES PNITROSOANILINE.

SPECIFIC FOR PRIMARY AMINE(ALI+ARO)
UNPLEASANT ODOUR OF
ISOCYNIDE(RNC) WITH
CHLOROFORM+KOH.
NITRO GROUP

THE PRESENCE OF NITRO GROUP CAN
BE DETYECTED BY REDUCING THE
COMPOUND WITH Sn/HCl AND THEN
CONDUCTING CARBYL AMINE TEST.