Post on 12-Feb-2022
Solution: Homogen mixture consists of two or more compound
Solute: compound which is diluted in solution (amount is smaller)
Solvent: compound that dilutes solut
solute + solvent Solution
(minor) (major) (homogen)
Concentration
Percentage
– % weight: g compound in 100.0 g solution (w/w)
– % volume : mL in 100.0 mL solution (v/v)
– % weight/volume : g in 100.0 mL solution (w/v)
Concentration expressions
• Molarity (M)• Normality (N)• Molality (m)• Mole fraction• Mole percent• Percent by weight (% w/w)• Percent by volume (% v/v)• Percent weight in volume (% w/v)• Milligrams per deciliter (mg/dL)• Osmolality (mOsmol/kg)• Osmolarity (mOsmol/L)
• MOLARITY : mol / liter solvent
• MOLALITY: mol solut / kg solvent
• ppm : part in a million solvent
• ppb: part solut in 109 solvent
• mol fraction: ratio of mol compound to overall mol
Colligative properties
• Increase of boiling point ( ΔTb)
• Decrease of freezing point ( ΔTf)
• Osmotic pressure ( π )
• Decrease of vapor pressure (Δp)
.
TASK
1.
(A)Determine molality of solut with freezing
point 0.450 oC? Kf = 1,86
(B)If this solution was made by diluting
2.12 g X in 48.92 g H2O. Count Molecular
weight of X compounds
2. The quantity of 42.5 g sucrose is
dissolved in 316 g of water. MW =342.3 g
mol-1 Kb = 0.51 Km -1 Kf = 1,86
(A) Calculate the boiling point
(B) Calculate the freezing point
Van’t Hoff
π= c R T
π= osmosis pressure
c = concentration
R = gas constant
0.08206
L atm mol-1K-1
T = absolute
temperature
Task
A Pharmacist dilutes 2.04 gram
haemoglobin in 100.0 mL. Osmotic
pressure is 5.83 mmHg at 22.5 oC.
Determine the massa molar of
haemoglobin?
pio : vapor pressure of the pure component
xi : the mole fraction of the component in solution
Task: at 25°C the vapor pressure of pure benzene
is 0,1252 atm. 6,40 g naphtalena(C10H8) is diluted in
78.0 g benzene(C6H6). Determine vapor pressure
benzene in solution
pH
• H2O has electrolyte characteristic, meaningwater can be ionized to release ion H+ danion OH-
• If water dilute in acid, acid will release ion H+
• If water dilute in base, base will release ionOH-
• Amount of [H+] in solution is used to statebase, acid or neutral.
Acid-Base Concept
17
Concept Acid Base neutralitation
Arrhenius increase the
concentration of H+
ions
increase the
concentration of OH-
ions
H+ + OH-
H2O
Brönsted Lowry donate a proton accept a proton Transfer of proton
Lewis electron pair acceptor. electron pair donor. covalen coordination
bonding
Dipol moment
• Electricity : in connection with natural
character of dynamical charge(for example
electron flow).
• In resting time, it called electrostatics.
For two charge separated by ( r ) the potential energy will be developed by Coulomb Law
U(r) = (q1.q2) / (4pe0r)
q1 and q2 coulomb (C); r metere0 (constant) = 8.854 x 10–12 C2/Nm2
Classification of aqueous solution system
Dispersion based on particle size of solute• True solution
a mixture of two or more components that form a homogeneous molecular or ionic dispersion
• Colloidal dispersiona homogeneous or heterogeneous mixture of two or more componentsin which the solute has a larger particle size
• Coarse dispersiona heterogeneous mixture of two or more components; particle are not individual molecules or ions but are aggregates of molecules or ions
Solution as ideal or real based on thermodynamics
• Ideal solutionsolutions for which there is no change
in the physical properties of thecomponents when they are mixed
• Real solutionsolutions for which changes in the
physical properties of solution occurwhen the components are mixed
Mixture of alcohol and water is an example
of non ideal solution
• the mixture gets warm, heat is given off.
• the final volume of the solutionis less than that of the sum of
the two components.• Raoult’s law is not linear
Type ofsolutionsystem
Approx.particle sizeof solute
Microscopevisibility Filter limit Diffusion
True solution Under 10Å None None Rapid
Colloidaldispersion
10Å – 5000Å1 mm – 0.5 m
Visible inelectronmicroscope
Passed throughfilter paper, notthrough semi-permeablemembrane
Slow
Coarsedispersion
Over 0.5 m Visible withlight andelectronmicroscope
Passed throughfilter paper, notthrough semi-permeablemembrane
Slow
Dispersions of solute
• An electrolyte is a substance (an acid, a base, or a salt), that inaqueous solution ionized to positive ions (cations) and negative ions (anions).
• Electrolyte properties in aqueous solution:» exhibit anomalous colligative properties compared with non-
electrolyte» can conduct an electric current» tend to show rapid chemical reactions compared with non-
electrolyte solution
Classification of electrolytes:• Strong electrolytes
completely ionized in waterdegree of ionization is pH-independent
• Weak electrolytes
ionized only partly in water
1. acid-strong acid (acid halogen, HNO3, H2SO4 )
2. base-strong base( alkaline base, Sr(OH)2, Ba(OH)2 )
3. All salts is strong electrolyte
4. Reaktion works fully
Strong electrolyte
Weak electrolyte
1. Other acids–acid acid-weak acid.
2. Other bases is base-weak base.
3. Salts which belong to weak electrolyte is mercuri salt(II)
4. Reaction is in equilibrium (electrolyte partly ionized).
• For non electrolytes
[(g/L)/MW] × 1000 = mOsmol/L
• For strong electrolytes
[(g/L)/MW] × (number of ions) × 1000 = mOsmol/L
• For any ions
[(g ion/L)/(ionic weight)] × 1000 = mOsmol/L
Osmolarity calculation
From %w/v:
mOsmol/L = [(g/L)/(MW)] × (number of ions) × 1000
TASK(1) osmolarity of 0.9% NaCl (MW 58.45)
(1) osmolarity of 5% dextrose (D5W); (MWdextrose = 198.17)
Pharmaceutical solutionsPharmaceutical solutions---------------------------------------------------------------------------Classification Characteristics
---------------------------------------------------------------------------Oral solution Taken by mouth, inactive for flavor and (elixir, syrup) viscosity, water usual solvent
Topical solution Application to skin or mucous membranes,aqueous or alcoholic
Otic solution For the ear; usually not aqueous; glycerin,(aural) propylene glycol, and polyethylene glycol
Ophthalmic For use in the eye, inactive for viscosity,solutions free of particulates, isotonic, sterile
Parenteral For injection iv, im, or sq; few if any aqueoussolutions inactive; rigid standards for sterility; free of
particulates; free of pyrogens; isotonic;immediate effect
---------------------------------------------------------------------------
Advantages of solution as dosage form:• faster onset of activity• good for children and the elderly• homogeneous• always uniform• flexible dosing• given by any route of administration
Disadvantages of solution as dosage form:• bulk• liquid that is inconvenient• leakage from container• less stability than solid dosage forms• more pronounced taste
Type ofsolutionsystem
Approx.particle sizeof solute
Microscopevisibility Filter limit Diffusion
True solution Under 10Å None None Rapid
Colloidaldispersion
10Å – 5000Å1 mm – 0.5 m
Visible inelectronmicroscope
Passed throughfilter paper, notthrough semi-permeablemembrane
Slow
Coarsedispersion
Over 0.5 m Visible withlight andelectronmicroscope
Passed throughfilter paper, notthrough semi-permeablemembrane
Slow
Dispersions of solute
Solutions ofnon-electrolyles
Solutions ofstrong electrolytes
In nonaqueous media• behave as ideal solution
E.g. sugar, alcohols,acetamide, acetone,glyceron
Characteristics of each type of solute
Solutions ofweak electrolytes
In aqueous media• do not conduct current• no ion present• exhibit regular colligative
properties
In nonaqueous media• form ion pairs
E.g. mineral acids, strongbases, all salts: HCl,NaCl, KOH, KCl, KAc
In aqueous media• conduct strong current• totally ionized• exhibit irregular
colligative properties(based on the number
of ions)
In nonaqueous media• behave as ideal solution
E.g. weak acids, weakbases: HOAc, NH4OH,benzoic acid, atropine
In aqueous media• conduct weak current• partially ionized• exhibit irregular
colligative properties(based on the number
of ions)