Activity 2: Conductometric titration of a cough syrup




Activity summary

What you must remember :
  • Conductivité
  • Conductivité ionique molaire

  Skills linked to the curriculum sequence 18 and sequence 20:

Compétences Capacités à maîtriser
 ANA Interpréter qualitativement l'allure de la courbe de titrage par suivi conductimétrique en utilisant des tables de conductivités ioniques molaires et en déduire le volume à l'équivalence du titrage.
 RÉA Réaliser un protocole de titrage mettant en jeu une réaction suivie par conductimétrie.

COM

Formuler et argumenter des réponses structurées.
Formuler et présenter une conclusion.


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Introduction
Objectives:
The present study developed and validated a conductometric method for determination of Diphenhydramine HCl (DPH) in its pure form and in a syrup formulation using silver nitrate (AgNO3).

Methods:
Conductometric titration method was achieved by using AgNO3. The method is built on the reaction of chloride ions coming from the DPH with Ag+ yielding silver chloride precipitate. Conductance of the solution is measured as a function of the volume of titrant. The proposed method is linear over the range of 1-10 mg.


Source: Conductometric determination of the antihistaminic diphenhydramine hydrochloride using silver nitrate as a titrant, Analytical chemistry department, Zagazig University, Egypt

Documents

Document 1: Diphynelhydramine HCl (DPH)

DPH (Fig. 1) is a first-generation anti-histaminic possessing anti-allergic, antitussive and sedative properties that is mainly used to treat allergies. It is found in various pharmaceutical preparations.

Document 1a Document 1b


Source: Conductometric determination of the antihistaminic diphenhydramine hydrochloride using silver nitrate as a titrant, Analytical chemistry department, Zagazig University, Egypt

Document 2: Cough syrup titration

A dose of cough syrup is titrated using silver nitrate titrant:

Document 2

Molar concentration of (Ag+,NO3-) solution: C = 5.10-3 M



Source: Conductometric determination of the antihistaminic diphenhydramine hydrochloride using silver nitrate as a titrant, Analytical chemistry department, Zagazig University, Egypt

Acquiring vocabulary

English French
conductimetric titration  
to treat allergies  
cough syrup  
titrant  


Problem solving
What is the mass of DPH in the dose of cough syrup titrated in document 2?




For teachers: more ideas and problems solved

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Source: « Résoudre un problème de physique-chimie dès la seconde » (Griesp)
Last modified: Monday, 29 January 2018, 1:11 PM