PHARMACEUTICAL CHEMISTRY LECTURE NOTES

ATTENTION:3RD YEAR STUDENTS:PLEASE READ AND UNDERSTAND WELL THE NOTES POSTED HERE..THIS COVERS PRE-MID EXAM...
Pharmaceutical Chemistry I
Supplemental Notes
Compiled by: MBTM

Fundamental Principles of Inorganic Chemistry
Matter- anything that occupies space and has weight.
Gases- kinetic theory of gases: gases lack definite shape or volume.
For example:
Gases are compressible and capable of expansibility. Just like the bottle of perfume left in an opened room, through w/c its fragrances can be felt at a distance.
Law of Gases:
Charles or Gay Lussac’s Law- states that the volume occupied by a certain gas is directly proportional to its absolute temp, if the pressure is kept constant:

V1 x T 2= V2 x T1 or V 1 T1
V2 T2
Boyle’s Law- states the volume of a given quantity of gas is inversely proportional to its pressure, provided the temperature is kept constant:

P1 x V1 = P2 x V2

Charle’s and Boyle’s Law is a combination of the 2 laws above and can be simplified as:

P1V1 = P2V2
T1 T2

Molecule = is the smallest particle of a substance that can exist free at ordinary conditions in nature.
Avogadro’s law- equal volumes of gas contained the same number of molecules.
Liquids- the liquid state have larger cohesive force, the greater density, less compressibility. And greater resistance to flow that the gaseous substance passes in the gaseous state.
Kinetic Theory of Liquids: liquids are mobile, i.e they move freely among themselves. The molecular attraction is increased while mobility is diminished upon applying pressure. they can be vaporized by lowering pressure and increasing pressure and increasing temperature. LIQUID ASSUME THE SHAPE OF THE CONTAINER OR THE VESSEL.

Solids – have crystalline form, some amorphous..
Kinetic theory of Solids- the molecules of solid do not move freely among themselves, or the attractive forces exerted by the molecules of solid are regarded as suspension to that of the molecules of liquids and gases. With few exceptions, all solid matters expand when heated.. in solids, either in amorphous or crystalline, it has a fixed melting point and is capable of undergoing sublimation. Meaning it exerts a definite pressure.
The following processes are applied to solids:
1. Sublimation: the process of changing the solid to vapor without passing the liquid state and condensing the vapor back to solid.
2. Melting point: temperature at which a solid is changed to liquid.
3. Freezing Point: Temperature at which a liquid solidifies.
4. Vapor pressure of solids: solids evaporate to a certain extent. The pressure exerted by their vapor is known as the vapor pressure of solids.

ELEMENTS
Symbol- is an abbreviation representing the element.. Ex. H, He, Ne
Symbolic Formula- is a combination of symbols expressing the compound molecule.
Thus, NaCl means one atom of Sodium and one atom of Chlorine, making together one molecule of Sodium Chloride.
Nomenclature- means the naming of a compound of elements based upon the Geneva Congress’s system, and the names maybe derived from the discoverer or place of discoverers, and either given in Latin or German titles.

Classification of Elements:
A. Metals- Possess characteristic metallic luster, are good conductor of heat and electricity, malleable, and ductile.
Classification of Metals: they are classified according to their chemical reactions as follows: the most common are:
a. Alkali metal- Li, Na, K, Cs, NH4. – univalent and form strong bases that are soluble in water.
b. Alkaline earth metals- Ca, Sr, Ba, Ra- bivalent and form strong bases that are soluble in water.
c. Weak bases- all monovalent respectively, Cu, Ag, and Au.
d. Stable bases- except Hg, which forms monovalent compounds, all are bivalent, the hydroxides are stable bases.
e. Amphoteric hydroxides-p Sn, Pb, and Ti family. Quadrivalent, also act as bivalent.
Occurrence of metals in nature: free or combined form as ores.
*Native metals: free are; Au, Ag, Pt, Cu, bi, As and Sb.
*Minerals: Ores are:
1. Oxides of Fe, Sn, Cu, Al
2. Sulfides of Ni, Cu, Sb, Pb, Cd, Zn, Co
3. Carbonates of Fe, Pb, Zn, Cu, Mn. Mg, Si, and Ca
4. Sulfate of Pb, Ba, Sr, and Ca.
Metallurgy- Science that deal with the methods of extracting the metal from their ores.
Principles involved in the metallurgy of any metal consists in spreading the ore from useless foreign material ( rocks, sand, clays, limestone) groups, with which it is associated in nature. The resulting product is then subjected to one of the FOLLOWING PROCESSES, DEPENDING UPON THE COMPOSITION OF THE ORE.
1. Segregation of the ore form the gangue: the native metals are separated from the matrix by heating it with a flux , the chemical nature of which is opposite of that of the gangue, and which combines with the matrix to form fusible clay, which separates from the molten metal. Thus, silicious gangue requires fusible silicate slag. The addition of CaCO3 to the metals therefore is necessary.
2. Roasting: the ore are converted into oxides and oxides are reduced by heating with C or finely powdered Al
3. Reduction: the carbonates are heated to drive out CO2, and the oxide
is reduced. The sulfides are roasted to remove the sulfur and convert the mineral into an oxide which is then reduced.
4. Refining or Purification: metals not easily reduced are obtained by
Electrolysis, whereby the pure metal is produced, or purification may be done by remelting the metal together with an appropriate slag, leaving behind the pure state.
Properties of Metal: metals form oxides, which form salts by direct combination
With non-metallic oxides and acids. They unite directly with the halogen forming
Halide. They form positive ions.
5. Alloys: materials composed of 2 or more metals intimately mixed
Together.
6. Amalgams: are alloys of mercury with any metals.

B. Non-Metals: their properties show opposite characteristic than that of metal. Ex. C, S, O, H. N. P, or generally those which are capable of forming the negative ions.
C. Metalloids: characteristic properties of which are midway that of metals and non-metals, or generally those which don’t show metallic physical properties, but chemically behave as metal.
Ex. Silicon
D. Isotopes they are atoms of the same atomic number but different atomic weights or mass number ..elemental forms that are chemically identical, but have different types of
Nuclei.
E. Isobars: atoms of the same mass number but different atomic number.
F. Isotones: atoms of different elements but have the same number of neutrons.

Radioactivity:
Elements emit the invisible rays or radio actions which travel in straight lines, as does ordinary light. The emission of these rays , alpha and beta rays, from the nucleus of the atoms of a radioactive element gives rise to the formation of other elements.
Alpha Rays: known as alpha particle, consist of Helium atoms which carry two(2) positive electrical charges.(C.T. Wilson succeeded in making photographs of the trade of the alpha particles by making them pass thru an atmosphere saturated with water.. As the particle moves they ionize the air with water. Velocities ranging as high as 17,000 Km per second .
Beta Rays: second kind of rays emitted from the atomic nuclei of radio active elements, consist of electrons moving in straight lines, which possess velocities ranging from 25,000 to 300, 000 kilometers per second,they are identical with the cathode and most much greater velocities.
Gamma Rays: produced by radioactive substances, corresponding to the x-rays, but the wavelength is shorter and their frequency is greater than that of the x-ray. The Gamma rays are produced as a result of bombardment of the radioactive atoms by the beta particles. for this reason everytime gamma rays are produced and have least ionizing power of all the 3 rays.
The three(3) rays have the ability to pass through matter. The order of their relative penetrating power is the reverse of their ionizing power . Gamma rays have the greater penetrating power, Beta rays are from 1 to 10 % as penetrating as gamma rays, but are about 100 times more penetrating than alpha rays.
The rays cause physiological effects, the beta and the gamma rays produce the greatest effects. They produced beneficial effects if certain skin diseases are exposed for a short period of time to their action. In the case of over exposure, however, painful ulcers attributed to the effect of Beta Rays develop. The penetrating gamma rays are considered mainly responsible for the curative property of radium salts in the treatment of cancer. The alpha rays have very little effect, because of the low penetrating power. Germ cells exposed to the rays are killed or at least have their development retarded, although growth of plants is stimulated by short exposure to the rays.

Ten (10 ) Most Abundant Elements in the Universe
1. Hydrogen 6. Carbon
2. Helium 7. Silicon
3. Oxygen 8. Magnesium
4. Neon 9. Iron
5. Nitrogen 10.Sulfur
Three (3) Most Abundant Element in the Universe
1. Hydrogen
2. Helium
3. Oxygen
Three ( 3) Most Abundant Element in the Earth Crust
1. Oxygen
2. Silicon
3. Aluminum
The Most Abundant of the Metals, 3rd most abundant element on Earth Crust
1. Aluminum
First Element Produced Artificially: Technetium
Element present in insulin: Zinc
Element common to all acid: Hydrogen
A true metal that causes minamata poisoning: Mercury
Metal contaminated in drinking water believed to be the caused of itai-itai disease in Japan: Cadmium
Relatively abundant element that is chemically active in Research involving
Photosynthesis: Magnesium
Laughing Gas: Nitrous oxide
Component of Hard water: Magnesium and Calcium
Densiest element in the Periodic table: Osmium
Acid found in the stomach: HCl
Heavy Water: D2O
Artificial Air: 20% Oxygen, and 80 % Helium
Discovered Oxygen : Scheele
Most active of metallic elements, alkali metal group, soluble group
St. Elmo’s Fire: Phosphorus
An adsorbent in the treatment of diarrhea, widely distributed in nature both in
Free and combined state.: Carbon
Halogen used as a common water disinfectant: Chloride
Groupings of Elements:
Group O - Noble (inert) gases… He, Ne, Ar, Kr, Xe, Rn
Group I-A- Alkali metals… H, Li, Na, K, Rb, Cs, Fr
Group II-A- Alkaline Earth… Be, Mg, Ca, Sr, Ba, Ra
Group III- A Boron Family… B, Al, Ga, In, Tl
Group IV –A Carbon family…C, Si, Ge, Sn, Pb
Group V-A- Nitrogen group… N, P, As, Sb,Bi
Group VI-A Chalcogen group… O, S,.Se, Te, Po
Group VII-A Halogens… F,Cl, Br, I, At
Group I-B Coinage elements… Cu, Ag, Au
Group II-B…. Volatile elements…. Zn, Cd, Hg
Group III-B ………Sc, Y
Group IV-B ………Ti, Zr, Hf
Group V-B ………V, Nb, Ta
Group VI-B ………Cr, Mo, W
Group VII-B ………Mn, Tc, Re
Group VIII-B ……… Fe, Co, Ru, Rh, Os, Ir, Ni, Palladium, Platinum
Take note starting from group III-B and ending at group II-B is the transition element. The inner transition elements are the lanthanides and actinide series

Introduction to Qualitative Analysis

Identifying Anions and Cations
Related Resources
• Analytical Chemistry• Chemistry Glossary• General Chemistry• Inorganic Chemistry• Periodic Table

Qualitative analysis is used to separate and detect cations and anions in a sample substance. In an educational setting, it is generally true that the concentrations of the ions to be identified are all approximately 0.01 M in an aqueous solution. The 'semimicro' level of qualitative analysis employs methods used to detect 1-2 mg of an ion in 5 mL of solution.
First, ions are removed in groups from the initial aqueous solution. After each group has been separated, then testing is conducted for the individual ions in each group. Here is a common grouping of cations:
Group I: Ag+, Hg22+, Pb2+
Precipitated in 1 M HCl
Group II: Bi3+, Cd2+, Cu2+, Hg2+, (Pb2+), Sb3+ and Sb5+, Sn2+ and Sn4+
Precipitated in 0.1 M H2S solution at pH 0.5
Group III: Al3+, (Cd2+), Co2+, Cr3+, Fe2+ and Fe3+, Mn2+, Ni2+, Zn2+
Precipitated in 0.1 M H2S solution at pH 9
Group IV: Ba2+, Ca2+, K+, Mg2+, Na+, NH4+
Ba2+, Ca2+, and Mg2+ are precipitated in 0.2 M (NH4)2CO3 solution at pH 10; the other ions are soluble
Many reagents are used in qualitative analysis, but only a few are involved in nearly every group procedure. The four most commonly used reagents are 6M HCl, 6M HNO3, 6M NaOH, 6M NH3. Understanding the uses of the reagents is helpful when planning an analysis.
Common Qualitative Analysis Reagents
Reagent Effects
6M HCl Increases [H+]Increases [Cl-]Decreases [OH-]Dissolves insoluble carbonates, chromates, hydroxides, some sulfatesDestroys hydroxo and NH3 complexesPrecipitates insoluble chlorides
6M HNO3 Increases [H+]Decreases [OH-]Dissolves insoluble carbonates, chromates, and hydroxidesDissolves insoluble sulfides by oxidizing sulfide ionDestroys hydroxo and ammonia complexesGood oxidizing agent when hot
6 M NaOH Increases [OH-]Decreases [H+]Forms hydroxo complexesPrecipitates insoluble hydroxides
6M NH3 Increases [NH3]Increases [OH-]Decreases [H+]Precipitates insoluble hydroxidesForms NH3 complexesForms a basic buffer with NH4+
Among the most common reactions in qualitative analysis are those involving the formation or decomposition of complex ions and precipitation reactions. These reactions may be performed directly by adding the appropriate anion, or a reagent such as H2S or NH3 may dissociate in water to furnish the anion. Strong acid may be used to dissolve precipitates containing a basic anion. Ammonia or sodium hydroxide may be used to bring a solid into solution if the cation in the precipitate forms a stable complex with NH3 or OH-.
Complexes of Cations with NH3 and OH-
Cation NH3 Complex OH- Complex
Ag+ Ag(NH3)2+ --
Al3+ --Al(OH)4-
Cd2+ Cd(NH3)42+ --
Cu2+ Cu(NH3)42+ (blue) --
Ni2+ Ni(NH3)62+ (blue) --
Pb2+ -- Pb(OH)3-
Sb3+ -- Sb(OH)4-
Sn4+ -- Sn(OH)62-
Zn2+ Zn(NH3)42+ Zn(OH)42-
A cation is usually present as a single principal species, which may be a complex ion, free ion, or precipitate. If the reaction goes to completion the principal species is a complex ion. The precipitate is the principal species if most of the precipitate remains undissolved. If a cation forms a stable complex, addition of a complexing agent at 1 M or greater generally will convert the free ion to complex ion.
The dissociation constant Kd can be used to determine the extent to which a cation is converted to a complex ion. The solubility product constant Ksp can be used to determine the fraction of cation remaining in a solution after precipitation. Kd and Ksp are both required to calculate the equilibrium constant for dissolving a precipitate in a complexing agent.