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Mansoura National University
Pharm D-Clinical Pharmacy Program Level 1 Pharm. Anal. Chem. 1 (PC 101)
5. Effect of Solvent
➢ The relation between the solute and solvent is very important in
determining solubility.
➢ Strong solute-solvent attractions result in greater solubility while weak solute-solvent
attractions result in lesser solubility.
➢ In turn, polar solutes tend to dissolve best in polar solvents while non-polar solutes
tend to dissolve best in non-polar solvents.
➢ A general rule to remember is, "Like dissolves like."
➢ Thus, The solubility of most inorganic compounds is reduced by the addition of
organic solvents such as methanol, ethanol, propanol, cyclohexane and acetone.
Examples:
• NaCl is soluble in water (polar solvent) but insoluble in cyclohexane (non-polar
solvent)
Precipitation Titration Curves
The titration curve is a graph showing how the concentration of a reactant varies as
titrant is added.
The titration curve for a precipitation titration follows the change
in either the analyte’s or titrant’s concentration as a function of the volume of titr
ant.
- +
For example, in an analysis for Cl using Ag as a titrant:
+ -
Ag (aq) + Cl (aq) AgCl (s)
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