Page 72 - PC 101 Interactive practical book

MANSOURA NATIONAL UNIVERSIY
PHARM D- CLINICAL PHARMACY LEVEL I PHARM. ANAL. CHEM. I (PC 101)

C Ca al lc cu ul la at ti io on ns s : :

Calculations in precipitation titration differ from that in acid-base titration in the

calculation of equivalence factor where (b) in precipitation titration equals the

number of univalent cation atoms present in or equivalent to ONE molecule of the

standard. In other words, (b) equals the total positive charge on the cation radical

of ONE molecule of the standard.

+1 +1 +2
ex.: For AgNO 3  b = 1, For NH 4SCN  b = 1, For Hg(NO 3) 2  b = 2

For this experiment:
Cl + Ag  AgCl 
+
-
 1 AgNO 3 ≡ 1 NaCl
standard sample

Equivalence factor (F):

1 x M.W. of NaCl x 0.01
each ml of 0.01 N AgNO 3 ≡ ≡ .......... g NaCl
1 x 1000

Concentration:

(E.P.- Ind. blank) x F x 1000
Concn. of NaCl = = .......... g/L
10

Results:
E.P. =

Concn. =

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