Page 47 - PC 101 practical notes 24-25..

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

P Pr ro oc ce ed du ur re e : :

1 E.P ph.ph.:

1) Transfer 10 ml of the mixture into a clean conical flask.

2) Add 10 drops ph.ph. indicator.

3) Titrate ≠ 0.2 N HCl.

{ Color change at E.P.: from Pink to Colorless }

2 E.P M.O.:

1) Transfer another 10 ml of the mixture into a clean conical flask.

2) Add 2 drops M.O. indicator.

3) Titrate ≠ 0.2 N HCl.
{ Color change at E.P.: from Yellow to Orange }

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

1 --
E.P 1 (ph.ph.) ≡ CO 3
2
-- -
E.P 2 (M.O.) ≡ CO 3 + HCO 3
 2E.P 1 ≡ CO 3
--

 (E.P 2 - 2E.P 1) ≡ HCO 3
-
For Na 2CO 3 :

Na 2CO 3 + 2HCl → 2NaCl + CO 2 + H 2O

 2 HCl ≡ 1 Na 2CO 3
standard sample

1
 1 HCl ≡ Na 2CO 3
standard 2 sample
Equivalence factor (F):
1 x M.W. of Na 2CO 3 x 0.2

each ml of 0.2 N HCl ≡ 2 ≡ .......... g Na 2CO 3
1 x 1000

47 | P a g e