Page 44 - PC 101 Interactive practical book

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

-
 [E.P 2 - 2(E.P 2 - E.P 1)] ≡ OH
For NaOH :

NaOH + HCl  NaCl + H 20

 1 HCl ≡ 1 NaOH
standard sample
Equivalence factor (F):

1 x M.W. of NaOH x 0.2
each ml of 0.2 N HCl ≡ ≡ .......... g NaOH
1 x 1000

Concentration:

[E.P 2 - 2(E.P 2 - E.P 1)] x F x 1000
Concn. of NaOH = = .......... g/L
10

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