PharChem Lecture Reviewer Part I

8/13/2019 PharChem Lecture Reviewer Part I

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PharChem Lecture Reviewer

Inorganic Pharmaceutical Chemistry Inorganic substances used as medicines/ preparation of pharmaceutical products

Elements

Group: Similar Properties Arrangement: Increasing Atomic Number

Periodic Functions Physical and Chemical Properties

Basis in the Study of Elements Periodic Table Electronic Configuration

Periodic Variation w/ increasing atomic number Periodic Variations

Metallic Properties

Decrease: Across Metals -> Metalloids -> Nonmetals

Increase: Top to Bottom Atomic Size

Decrease: Across Increasing nuclear change and valence electrons

Increase: Top to Bottom Increasing energy level

Ionization Energy Tendency of an atom to resist the loss of an electron Higher: Nucleus Hold on the Electron (strong) Increase: Across Decrease: Top to Bottom

Electron Affinity Tendency of an atom to gain an electron More Negative: Greater gain Increase: Across Decrease: Top to Bottom

Electronegativity Ability of an atom to attract electrons Increase: Across Decrease: Top to Bottom

Group I-A THE ALKALI METALS Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs) and Francium (Fr) Large w/ one valence electron (ns1)


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Easy Removal (ionization) Difficulty of Removal decreases; Atomic Radius increases Very Good Reducing Agents Very Active Metals Reactivity increases w/ increasing Atomic Weight Cesium Most Active Metal Francium unstable radioactive species Never found in nature (free state) +1 oxidation state Salts

Water Soluble (most soluble) (exception: Li small size makes some salts insoluble;ex. Fluoride, Carbonate and Phosphate)

Chemical Incompatibilities rare Monovalent Copper and Gold

Unstable; permits ionization Monovalent Silver

Stable Form Hydroxides

Strongly Basic (except LiOH small size of Li and covalent character) Combined with: Hydrogen (Hydrides), Halogens (halides) and Oxygen{oxidation state: -

1/2} [Li (normal oxides), Na (peroxides) and K, Rb and Cs (superoxides)] React Vigorously w/ water forming hydrogen gas and metallic hydroxides; stored under

kerosene and coated w/ paraffin [Hydrides (hydrogen gas and metal hydroxide), Oxides(Hydroxides), and Peroxides and Superoxides (Oxygen and Hydroxides)].

Group I-B THE COINAGE METALS Copper (Cu), Silver (Ag), and Gold (Au) Ornamental and coinage purposes Single Valence Electron Complete shell (18 electrons) Monovalent state

Ion is colorless and diamagnetic Polyvalent Form

deficiency in the outer shell are colored Ions are colored and paramagnetic

Transition elements Partially filled d orbitals Colored


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Comparison of Group I-A and Group I-B Metals:

Alkali Metals Coinage MetalsDo not occur free in nature (salts) Occur free in nature; easily recovered (reduction)Very Active; displace other metals. ChemicalActivity increases as atomic weight increases.

Not Active; displaced by other metals. ChemicalActivity decreases as atomic weight increases.

Oxides and Hydroxides (Strongly Basic) Oxides and Hydroxides (Feebly)Exception: Ag 2O (active basic oxide)

Halides (soluble; not hydrolyzed) Nearly InsolubleException: Silver Halides (readily hydrolyzed; formbasic salts)

Univalent (One Series of Compounds) Silver (I) and Gold (I and III) one series eachSimple Cations, never in complex anions and doesnot form complex cations w/ NH 3.

Form Complex AnionsForms Complex Cations w/ NH 3.

Rapidly Oxidized Slowly Oxidized

Group II-A THE ALKALINE EARTH METALS Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba) and Radium

(Ra) Definite Metallic Properties (Beryllium least metallic) Good conductors of heat and electricity Magnesium- only one used as a metal Beryllium - rare and costly Calcium, Strontium and Barium too reactive Radium - radioactive species Lose their 2 electrons to form 2+ ions Strong Reducing agents (Exception: Be) Chemical Activity increases as the atomic radium increases (greater bond formation) Combine with oxygen, halogens, nitrogen, sulfur and hydrogen (except Mg) Calcium, Strontium and Barium react with cold water Magnesium reacts with steam (liberates hydrogen gas and forms alkaline solution) Beryllium oxide - amphoteric (presence of an acid (base), it is a base (acid)) Other oxides basic Hydroxides increase base strength (down) Salts

Hydrated with smaller cations; high hydration affinity (greater density of positivecharge)

Group II-B Metals Zinc (Zn), Cadmium (Cd) and Mercury (Hg) Zn and Cd are soft metals Hg - liquid; quicksilver (silver white appearance)


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Filled set of d orbitals Terminal Elements

Diamagnetic and colorless Utilize electrons for bonding purposes Oxidation state: +2 Divalent ions (Exception: Hg has a monovalent ion mercurous) Reacts with Halogens, Oxygen, Nitric Acid and common oxidizing agent Forms complex ions (amines, cyano-and halo-) and coordination compounds Forms adherent oxide or basic carbonate coating (prevents oxidation) Zinc galvanized iron Used in alloys (alloys of mercury are called amalgams)

Brass (copper and Zinc) Bronze (copper and Tin)

Oxides and Hydroxides - weak bases (base strength increasing going down)

Zn(OH)2 amphoteric; reacts w/ acid and bases

Group III-A Elements Boron (B), Aluminum (Al), Gallium (Ga), Indium (In) and Thallium (Tl) B and Al most important to pharmacy Al amphoteric, abundant; most common metal and 3 rd most common element (oxygen

- 1 st and silicon 2nd ) in the earths crust B non-metal/metalloid (hybrid behavior; borderline element) Electron Configuration: s2p1 Oxidation state: 3+

Boron Bonding more covalent than ionic Aluminium forms both covalent and ionic bonds Stable (ordinary temperature) Oxidizes when heated in air Oxides reduced back to the free metals React with sulfur and halogens Hydroxides - amphoteric properties (exception: B and Tl)

Group III-B The Scandium Subgroup Scandium, Yttrium, Lanthanum, Actinium, Lanthanides and Actinides (two inner

transition series) Lanthanides

rare elements (58-71) La through Lu Mixtures hard to separate (similar chemical properties)

Actinides 90-103


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Ac through Lr Elements beyond uranium are prepared synthetically; radioactive isotopes (not very

stable) Forms compounds with the 2+ and 3+ oxidation states Physical Properties: Typical Metals Reactive chemically and the oxides are basic Uranium fuel; radioactive element

Group IV-A Elements THE CARBON FAMILY Carbon (C), Silicon (Si), Germanium (Ge), Tin (Sn) and Lead (Pb) C and Si non-metals; Sn and Pb metals; Ge Metalloid Carbon

Reducing agent Basic building unit of organic compounds Inert (room temperature) Combines w/ oxygen, halogens and other non-metals at elevated temperature Occurs in inorganic compounds (Carbonates, oxalates, tartrates and acetates)

Silica and metal silicates found everywhere on the earths crust Silicon never exists in the free state Germanium rare element; minute quantities (metal sulfides); active metal Tin oxides SnO2 and lead sulfides (PbS galena) Oxidation states: 2+ and 4+ Valence electron: s2p2

Lead and Tin give up two unpaired p electrons (Pb2+ and Sn2+) form common oxides active metals (displace hydrogen gas from acids and combine with non-metals) Oxides and hydroxides amphoteric

o Tin stannite ion (base)o Lead plumbiteo 4+ - stannites and plumbates (base)

4+ oxidation state - more covalent bond character (stability decreases)

Group IV-B THE TITANIUM SUBGROUP (more common than Group III-B) Titanium (Ti), Zirconium (Zr) and Hafnium (Hf) Titanium commercial use; red color (hydrogen peroxide in acid solutions) Titanium dioxide pigment (good covering power and inert) Form compounds with oxidation states of 2+(good reducing agents), 3+ and 4+(most

common). Difficult to prepare the pure metal (affinity for carbon, nitrogen, oxygen and hydrogen)

PharChem Lecture Reviewer Part I

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