Page 33 - Pharmaceutical_Analytical_Chemistry_1_Theoretical_Notes_Level_1 2024-2025

Mansoura National University
Pharm D-Clinical Pharmacy Program Level 1 Pharm. Anal. Chem. 1 (PC 101)

Concentration Units

➢ There are numerous ways of expressing the concentration of a solution, from which

we will study only two:

I. Molarity (M)

II. Normality (N)

I. Molarity (molar concentration) (M)

❑ The number of moles of solute per 1 liter of solution.
Definition
❑ The most commonly used unit in chemistry.

Law = =

Example 0.5 M NaOH means 0.5 mole NaOH /1L solution

-1
Unit (mol/L) or (mol.L ) or M

Molarity Calculations

➢ To calculate the molarity, we must know the number of moles of solute and the

number of liters of solution.

=

No of moles = M X No of liters (V),

where M = Molarity; V = Volume

No of liters = Number of moles / M

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