key point of slides: Definition of Solution Composition of Solution System Vs Phase Physical Properties of solution Type of solutes Type of solution (on basis of) Dispersed Particle State of matter Use of solution

1. Physical Pharmacy Lecture Series
Lecture# 06
Physico-chemical Principles (Solution)
Solution
Basics
Concentration Expression
Partition Coefficient
Ideal Vs Real Solution
Colligative Properties

2. Solution
• Definition of Solution
• Composition of Solution
• System Vs Phase
• Physical Properties of solution
• Type of solutes
• Type of solution (on basis of)
• Dispersed Particle
• State of matter
• Use of solution
Basic of Solution (Lecture # 06)

3. Solution:
“A homogenous mixture
of two or more substances on
molecular level is called
solution”.
Solution (Basic L#06)

4. Solution:
“A homogenous mixture of
chemical substances, which
has the same chemical
composition and physical
properties, is called solution”.
Solution (Basic L#06)

5. Solution:
“Homogenous mixture that is prepared by
dissolving a solid, liquid or gas in another
liquid and represents a group of
preparations in which the molecules of the
solute or dissolved substance are
dispersed.”
• Solutions may be prepared from any combination of solid, liquid
or gas, the three states of matter.
• In solution, the mixing substances do not react chemically with
each other but only physical changes take places.
Solution (Basic L#06)

6. Composition of Solution:
Solution is usually composed of two components
i.e. solutes & solvents.
Solute:
“The component of the solution, which is
present in small quantity and is in dissolved form
is called solute.”
Solvent:
“The constituent of the solution, which is
present in large amount and dissolves the solute,
is called solvent.”
Solution (Basic L#06)

7. System and Phase:
System:
“A system is a bounded space or a definite
quantity of substance, which is under
observation or experiments”.
Phase:
“A distinct system’s homogeneous part
separated by definite boundaries from
other parts of the system is called phase”.
Solution (Basic L#06)

8. Physical Properties of
Solution:
On the physical basis, the properties of the
solutions can be classified into 03 in
types:
• Additive Properties
• Constitutive Properties
• Colligative Properties
Solution (Basic L#06)

9. 1) Additive Properties:
“The physical properties, which depend
upon the sum of the properties of all the
constituents (i.e. atoms of molecules) of the
solution, are called additive properties.”
Example:
• Mass
• Volume
• Molecular weight
Solution (Basic L#06)

10. 2) Constitutive Properties:
“The physical properties, which depends
on the arrangement of the atoms within the
molecule, are constitutive properties.”
“The constitutive properties mainly depend on the
arrangement and to a lesser extent on kind and number of atoms.”
Examples:
• Refractive Index
• Electrical Properties
• Solubility
• Surface Tension
• Surface and interfacial characteristics.
Solution (Basic L#06)

11. 3) Colligative Properties:
“The physical properties of the solutions which
depend on the number of atoms of the solution are
called colligative properties.”
Examples:
Some important are as follows:
• Elevation in Boiling Point
• Lowering of Vapour Pressure
• Depression in Freezing Point
• Osmotic Pressure
Note:
• The values of colligative properties are approximately same for the
solutions of same concentration.
Solution (Basic L#06)

12. Types of Solutes:
The solutes (whether they are in
liquid, solid or gaseous phase) are
classified into 02 types on the basis of
their electrical properties:
•Electrolytes
•Non-Electrolytes
Solution (Basic L#06)

13. 1) Electrolytes:
“Those solutes, which are ionized in the solution
and conduct electricity are said to be electrolytes.”
• Such solutes show greater colligative properties as compared to other
solution with same concentration.
• Electrolytes are subdivided into 02 types, which are given below;
Strong Electrolytes:
“Those electrolytes which ionize completely in the solution are called
strong electrolytes.”
Examples: NaCl, Na2 SO4, HCl etc.
Weak Electrolytes:
“Weak electrolytes ionize in the solution partially.”
Example: Ephedrine, Phenobarbital etc.
Solution (Basic L#06)

14. 2) Non-Electrolytes:
“Those solutes, which do not
ionize in the solution and so such
solution cannot conduct electricity are
called non-electrolytes.”
Examples:
• Sucrose
• Glucose
• Urea
• Naphthalene
Solution (Basic L#06)

15. Types of Solution: (on basis of)
• Dispersed molecules
• State of matter
• Use of Solution
Solution (Basic L#06)

16. 1) Types of Dispersed
System or Solution:
“A system in which one substance is dispersed as
particles throughout the continuous dispersion medium
is called dispersed system”.
On the basis of dispersed particles or solute molecules,
solutions are classified into 03 types;
• True solution
• Colloidal Dispersion
• Coarse Dispersion
Solution (Basic L#06)

17. 1) True Solution:
“A solution resulted due to homogenous
dispersion of ions or molecule of one component
throughout the other is called true solution”.
• The particle size in the true solution is smooth and is less than 10
A° (1 nm).
Example:
• Ionic dispersion is solution of NaCl in water.
• Molecular dispersion is solution of sucrose in water.
• In true solution, when solute is dissolved in solvent,
the volume of solvent remains the same, because the
solute molecules adjust themselves in the
intermolecular spaces of solvents.
Solution (Basic L#06)

18. 2) Colloidal Dispersion:
“A solution, which may be
homogeneous or heterogeneous dispersion
with particles size between that of true
solution and coarse dispersion is called
colloidal dispersion or solution”.
• The particles or solute size in colloidal dispersion is between 10 A°
and 2000 A°.
• A colloidal dispersion with homogeneous dispersion is that of
acacia (sodium carboxymethyl cellulose) in water.
• And a colloidal solution with heterogeneous dispersion is that of
silver protein ate in water.
Solution (Basic L#06)

19. 3) Coarse Dispersion:
“A solution / dispersion in which particle
or solute size is maximum is called coarse
dispersion”.
• The particle or solute size in such dispersion is larger that 2000 A°.
• As the particles size is very large, so cannot adjust themselves between
the intermolecular space of solvent.
Example:
• Emulsion i.e. milk, mixture of oil and water.
• Suspension.
Solution (Basic L#06)

20. 2) Types of Solution on state of matter:
Solution (Basic L#06)

21. 3) Classification of Solution on
basis of uses:
Solution (Basic L#06)

22. Other topic of solution:
Solution
Basics (Done)
Concentration Expression
Partition Coefficient
Ideal Vs Real Solution
Colligative Properties
Solution (Basic L#06)

23. End
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