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LAB REPORT FOR EXPERIMENT #2: PURIFICATION OF

 ACETANILIDE BY RECRYSTALLIZATION

Your name TA’s name

Your Partner’s name Lab Section

OBSERVATIONS:

 A. SELECTING A RECRYSTALLIZATION SOLVENT

Solubili! T" $%ol&' Solubili! T" $(o'

Water insoluble soluble

pet ether insoluble insoluble

ethanol fairly soluble readily soluble

acetone very soluble readily soluble

After looking at the solubility of impure acetanilide in

the four solvents, ater seems to be the best choice as arecrystalli!ing solvent"

B. DECOLORIZING A SOLUTION OF IMPURE ACETANILIDE AND )OT

FILTRATION#" $"%&'( grams of impure acetanilide

%" ') ml total solvent volume

(" Added tip of carbon black to mi*ture and mi*ture almost

boiled over+

)" #) ml total solvent volume

C. ISOLATING T)E RECRYSTALLIZED PRODUCT *IT) VACUUMFILTRATION

#" hilled crystals in ice bath for $- minutes"

collected flaky hite crystals

.ass of atch glass and acetanilide / ##"%0()

.ass of atch glass / #$"&-1'

.ass of recovered acetanilide / 1")%(% g

.ass of impure acetanilide / $"%&'( g

Percent recovered / %0") 2

D. DETERMINING T)E MELTING RANGE

.elting range of recrystalli!ed acetanilide / $$# 3 $$0 o

.elting range of impure acetanilide / $1% 3 $$$ o

CONCLUSION:4n this e*periment a techni5ue as used that ill be used

fre5uently throughout the semester6 Purification by

recrystalli!ation" This techni5ue allos for the

purification of a crude material" The small loss in yield

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is made up by the high gain in purity" The purity of the

material obtained can be correlated to the sharpness and

veracity of the melting point data and this as observed"

+UESTIONS:

$" 7id recrystalli!ation improve the purity of youracetanilide8 9o can you tell8

Yes, the melting point range of the recrystalli!ed

material as very narro and as close to the literature

value"

#" Assume that your original sample of acetanilide as -12

pure" What as the ma*imum amount of pure acetanilide

that you could recover after your recrystalli!ation8

.ass of impure acetanilide / $"%&'( g

.ass of ma*imum amount of pure acetanilide / $"%&'( : -12

/ $"01(' g

'" 9o much acetanilide did you lose during the entire

recrystalli!ation process8 Where did the losses probably

occur8

.ass of recovered acetanilide / 1")%(% g

.ass of lost acetanilide / $"01(' ; 1")%(% / 1"%0-) g

$< 4n the hot filtration step, material crystalli!ed in

filter paper"

#< 4n the second filtration step, material as lost on

filter paper

'< .aterial did not completely crystalli!e from solution