Systematic Qualitative Analysis, Group IA, and Group IB Elements Study Notes

General Qualitative Analysis and Periodic Properties

• Cation Group Classifications and Precipitation Reagents:

  • Group I (Insoluble Chloride Group): Forms precipitates with diluted $HCl$. Elements yield insoluble chlorides.

  • Group II (Acid Insoluble Sulfide Group): Forms precipitates with $H_2S$ in an acidic medium.

  • Group III (Base Insoluble Sulfide Group): Forms precipitates with $(NH_4)_2S$ in a basic medium.

  • Group IV (Insoluble Phosphates, Sulfate, and Carbonates Group): Forms precipitates with $(NH_4)_2HPO_4$ and $NH_3$.

  • Group V (Soluble Group): Yields no precipitate with any of the systematic group reagents.

• Flame Tests:

  • Conducted using a non-luminous flame.

  • Cobalt Glass: Used to view the violet flame of Potassium ($K$) by filtering out the intense yellow flame emitted by Sodium ($Na$).

  • Elements Analyzed via Flame Test: Sodium ($Na$), Potassium ($K$), Calcium ($Ca$), Strontium ($Sr$), Lithium ($Li$), Barium ($Ba$), Borates ($BO_3^{3-}$), Copper ($Cu$), Thallium ($Tl$), Phosphorus ($P$), Lead ($Pb$), Arsenic ($As$), Antimony ($Sb$), Bismuth ($Bi$), Ammonium ($NH_4^+$), and Magnesium ($Mg$).

• Abundance Rankings:

  • Most Abundant Elements in the Earth's Crust:

    1. Oxygen ($O$)

    2. Silicon ($Si$)

    3. Aluminum ($Al$)

  • Atmospheric Gases:

    • Most abundant gas in air: Nitrogen ($N_2$).

    • Composition of dry air: Nitrogen ($N_2$) and Oxygen ($O_2$) present in a $78:21$ proportion.

  • Noble Gases:

    • Most abundant noble gas: Argon ($Ar$).

    • Least abundant noble gas: Radon ($Rn$).

• Physiological Ion Distribution:

  • Intracellular Fluid (ICF):

    • Primary Cation: Potassium ($K^+$)

    • Secondary Cation: Magnesium ($Mg^{2+}$)

    • Primary Anion: Phosphate ($HPO_4^{2-}$ / $PO_4^{3-}$)

    • Secondary Anion: Protein and Sulfate ($SO_4^{2-}$)

  • Extracellular Fluid (ECF):

    • Primary Cation: Sodium ($Na^+$)

    • Secondary Cation: Calcium ($Ca^{2+}$)

    • Primary Anion: Chloride ($Cl^-$)

    • Secondary Anion: Bicarbonate ($HCO_3^-$)

• Physiological Buffer System:

  • The Bicarbonate / Carbonic Acid system ($HCO_3^- : H_2CO_3$) serves as the primary and most important physiological buffer system in human plasma.

• Color Codes for Compressed Gas Cylinders and Containers:

  • Carbon Dioxide ($CO_2$): Gray

  • Nitrogen ($N_2$): Black

  • Nitrous Oxide ($N_2O$) / Milk of Magnesia: Blue

  • Helium ($He$): Brown

  • Oxygen ($O_2$): Green

  • Argon ($Ar$): Dark Green

  • Acetylene ($C_2H_2$): Red

  • Chlorine ($Cl_2$): Yellow

• Sulfide Precipitate Color Exceptions:

  • As a general rule, all metal sulfides are Black, except for the following specific precipitates:

    • Cadmium Sulfide ($CdS$): Yellow

    • Zinc Sulfide ($ZnS$): White

    • Manganese Sulfide ($MnS$): Pink / Flesh-colored

    • Antimony Sulfide ($Sb_2S_3$ / $SbS$): Orange

• Distinct Elemental Characteristics:

  • Most Metallic Halogen: Iodine ($I$) / Astatine ($At$)

  • Most Potent Respiratory Stimulant: Carbon Dioxide ($CO_2$) at concentrations of $7\text{--}10\text{\%}$

  • Heaviest (Highest Atomic Number) Stable Element: Bismuth ($Bi$, atomic number $83$)

  • Densest Element: Osmium ($Os$)

  • First Artificially Produced Element: Technetium ($Tc$)

Group IA: Alkali Metals and Hydrogen

• Group IA Physical and Chemical Trends:

  • Members: Hydrogen ($H$), Lithium ($Li$), Sodium ($Na$), Potassium ($K$), Rubidium ($Rb$), Cesium ($Cs$), Francium ($Fr$).

  • Represents the most chemically reactive group of metals.

  • Alkalinity: Increases with increasing atomic number.

  • Degree of Solvation: Decreases with increasing atomic number.

  • All Group IA elements exhibit high positive oxidation potentials with low ionization potentials, with the exception of Hydrogen ($H$).

  • Lithium ($Li$), Sodium ($Na$), and Potassium ($K$) metals react violently with moisture and oxygen; they must be stored submerged under kerosene.

• Hydrogen ($H$):

  • Synonym: Inflammable air.

  • Lightest known element and the most abundant element in the universe.

  • Industrial Preparation: Prepared via the Messerschmidt Process and the Lane Process (producing $99\%$ pure Hydrogen gas).

  • Isotopes:

    • Protium ($^1H$): Most abundant natural isotope.

    • Deuterium ($^2H$ or $D$): Used in the synthesis of Heavy Water ($D_2O$).

    • Tritium ($^3H$ or $T$): Radioactive isotope.

  • Combustion with Oxygen produces Water ($2H_2 + O_2 \rightarrow 2H_2O$).

  • Steam / Water vapor is recognized as the best natural expectorant.

Water Types, Hardness, and Purification

• Classification of Waters:

  • Natural Water or Mineral Water: Contains dissolved minerals, variable amounts of suspended matter, traces of atmospheric gases, ammonia, and metabolic decomposition products. It is unpalatable and unfit for drinking.

  • Purgative Water: Contains high concentrations of Sodium Sulfate ($Na_2SO_4$), Magnesium Sulfate ($MgSO_4$), and Sodium Bicarbonate ($NaHCO_3$).

  • Effervescent Water: Charged with Carbon Dioxide ($CO_2$) under pressure; contains dissolved Calcium and Magnesium Carbonates held in solution as bicarbonates.

  • Chalybeate Water: Contains dissolved Iron salts, characterized by a distinct ferruginous (iron-like) taste.

  • Lithia Water: Bottled or natural water that does not contain appreciable quantities of Lithium salts.

  • Saline Water (Bitter Water): Contains relatively high amounts of Magnesium Sulfate ($MgSO_4$), Sodium Sulfate ($Na_2SO_4$), and Sodium Chloride ($NaCl$).

  • Sulfur Water: Contains dissolved Hydrogen Sulfide ($H_2S$) gas and deposits elemental Sulfur upon exposure to the atmosphere.

  • Siliceous Water: Contains dissolved soluble alkali silicates.

  • Potable Water: Water suitable and safe for drinking. Meets public health criteria for total freedom from coliform organisms.

    • USP Definition: Water obtained by distillation, ion-exchange, or reverse osmosis.

  • Purified Water, USP: Used strictly for extemporaneous compounding and preparation of official test reagents. Unfit for parenteral administration.

• Water Hardness:

  • Soft Water: Contains low or negligible amounts of Calcium ($Ca^{2+}$) and Magnesium ($Mg^{2+}$) ions.

  • Temporary Hardness: Caused by dissolved Magnesium and Calcium bicarbonates ($Mg(HCO_3)_2$ and $Ca(HCO_3)_2$).

    • Removal Methods: Can be removed by simple boiling or by the addition of Lime ($Ca(OH)_2$).

  • Permanent Hardness: Caused by dissolved Magnesium and Calcium sulfates, chlorides, and nitrates.

    • Removal Methods: Requires specialized water softening procedures, such as ion-exchange resins or chemical precipitation.

Group IA Compounds and Applications

• Hydrogen Peroxide ($H_2O_2$):

  • Synonyms: Perhydrol, Agua Oxinada, Oxygenated acid, Oxygenated water.

  • Uses: Antiseptic for wound care, wound cleansing, and as a mouthwash.

  • Preparations:

    • 10-volume solution ($3\%\,\text{w/v}$): Hydrogen Peroxide Topical Solution, USP. Contains Acetanilide ($0.03\%$ ) as a stabilizer to prevent decomposition.

    • 20-volume solution ($6\%\,\text{w/v}$): Used as a hair bleach and disinfectant.

• Lithium ($Li$):

  • Lightest metal.

  • Pharmacologic Action: Mood stabilizer (central nervous system depressant), diuretic.

  • Lithium Carbonate ($Li_2CO_3$):

    • Drug of Choice (DOC): Bipolar Disorder and Mania.

    • Brand Names: Eskalith®, Lithase®, Quilonium-R®.

• Sodium ($Na$):

  • Synonym: Natrium.

  • Principal extracellular cation.

  • Preferred cation choice for organic and medicinal pharmaceutical salts.

  • Pharmacologic Effect: Causes systemic fluid retention (edema).

  • Sodium Acetate ($CH_3COONa$): Diuretic, systemic and urinary alkalizer, and alkalinizing agent for Benedict's Solution.

  • Sodium Bicarbonate ($NaHCO_3$):

    • Synonym: Baking Soda.

    • Synthesized industrially via the Solvay Process.

    • Provides the second major anion ($HCO_3^-$) in the extracellular fluid.

    • Systemic antacid and systemic alkalizer.

    • Antidote for mineral acid ingestion/poisoning.

    • Enhances the renal elimination of acidic drugs (e.g., salicylates, barbiturates).

  • Sodium Phosphate Salts:

    • Monobasic Sodium Phosphate ($NaH_2PO_4$): Source of phosphorus in hypophosphatemia and total parenteral nutrition (TPN); indirectly lowers elevated plasma calcium levels.

    • Dibasic Sodium Phosphate ($Na_2HPO_4$): Primary anion source in intracellular fluid; acts as a saline laxative.

    • Tribasic Sodium Phosphate ($Na_3PO_4$): Highly basic with no medicinal or pharmacologic applications; used exclusively for cleaning specialized laboratory glassware.

  • Sodium Potassium Tartrate ($KNaC_4H_4O_6 \cdot H_2O$):

    • Synonyms: Rochelle Salt, Sal Seignette.

    • Functions as a saline laxative and as a sequestering agent in Fehling's Solution.

  • Sodium Borate ($Na_2B_4O_7 \cdot 10H_2O$):

    • Synonym: Borax.

    • Pharmaceutic necessity as an alkalinizing agent; used as a buffering component in eyewashes.

  • Sodium Carbonate ($Na_2CO_3$):

    • Anhydrous Form: Soda Ash.

    • Dihydrate Form: Trona.

    • Decahydrate Form ($Na_2CO_3 \cdot 10H_2O$): Soda Crystals, Washing Soda, Sal Soda.

  • Sodium Chloride ($NaCl$):

    • Synonyms: Table salt, Rock salt, Sea salt, Solar salt, Dendritic salt.

    • Provides Chloride ($Cl^-$), the major extracellular anion.

    • Electrolyte replenisher supplied as Normal Saline Solution (NSS, $0.9\%\,\text{w/v}$ $NaCl$).

    • Ringer's Solution: Contains $NaCl$, $KCl$, and $CaCl_2$ dissolved in water.

    • Lactated Ringer's Solution: Contains $NaCl$, $KCl$, $CaCl_2$, and Sodium Lactate (also known as Hartmann's Solution).

    • Oral Rehydration Salts (ORS): Combination of $NaCl$, Glucose, $KCl$, and Sodium Citrate.

  • Sodium Gluconate: Electrolyte replenisher.

  • Sodium Citrate:

    • In vivo: Systemic and urinary alkalizer, expectorant.

    • In vitro: Anticoagulant (chelates Calcium ions).

  • Sodium Fluoride ($NaF$):

    • Anticariogenic agent added to dentifrices.

    • Excessive ingestion of fluoride leads to dental fluorosis (mottled enamel).

    • Note: Hydrofluoric acid ($HF$) is used for glass etching and causes deep, slow-healing tissue burns.

  • Sodium Hydroxide ($NaOH$):

    • Synonyms: Caustic Soda, Lye Sosa, Soda Lye.

    • Highly deliquescent solid that rapidly destroys animal tissue through Liquefaction Necrosis (distinct from strong acids, which induce coagulative necrosis).

    • Saponifying agent for the production of hard soaps.

  • Soda Lime (Calx Sodica):

    • Mixture of Calcium Hydroxide ($Ca(OH)_2$) with Sodium Hydroxide ($NaOH$), Potassium Hydroxide ($KOH$), or both.

    • Efficient Carbon Dioxide ($CO_2$) absorber utilized in anesthesia machines, closed-circuit oxygen therapy, and metabolic testing.

  • Sodium Hypochlorite ($NaOCl$) Formulations:

    • Sodium Hypochlorite Solution, USP: $4\%\text{--}6\%\,\text{w/w}$ solution; commercial bleaching agent and disinfectant.

    • Labarraque's Solution: $2.5\%\,\text{w/w}$ $NaOCl$ solution used as a disinfectant.

    • Dakin's Solution: $0.5\%\,\text{w/v}$ $NaOCl$ solution buffered with Sodium Carbonate ($Na_2CO_3$) and Boric Acid ($H_3BO_3$).

    • Modified Dakin's Solution: $0.5\%\,\text{w/v}$ $NaOCl$ solution buffered with Sodium Bicarbonate ($NaHCO_3$).

  • Sodium Iodide ($NaI$):

    • Essential source of iodide required for thyroid hormone synthesis (Triiodothyronine [$T_3$] and Thyroxine [$T_4$]).

    • Functions as an expectorant.

    • Pharmaceutical necessity to solubilize elemental Iodine ($I_2$) in aqueous solutions.

  • Sodium Sulfate ($Na_2SO_4$):

    • Synonym: Glauber's Salt.

    • Saline laxative; Sulfate ion ($SO_4^{2-}$) is poorly absorbed across the gastrointestinal mucosa.

  • Sodium Nitrate ($NaNO_3$):

    • Synonyms: Chile Saltpeter, Salitre.

    • Used as a food preservative.

  • Sodium Tartrate:

    • Primary standard for Karl Fischer Reagent (KFR) in Method I (Titrimetric Water Content Determination).

    • Possesses laxative and diuretic activity.

  • Sodium Nitroprusside: Potent hypotensive agent administered intravenously in hypertensive emergencies.

  • Sodium Polystyrene Sulfonate:

    • Brand Name: Kayexalate®.

    • Cation-exchange resin indicated for the treatment of hyperkalemia resulting from severe renal insufficiency.

  • Sodium Ascorbate: Active Pharmaceutical Ingredient (API) for Vitamin C supplementation; acts as a water-soluble antioxidant.

  • Sodium Formaldehyde Sulfoxylate: Best and most specific antidote for Mercuric Chloride ($HgCl_2$) poisoning.

  • Sodium Thiosulfate ($Na_2S_2O_3$):

    • Synonyms: Hypochlor, Photographer's Hypo, Hypo.

    • Antidote for Cyanide poisoning, administered sequentially with Sodium Nitrite ($NaNO_2$).

    • Volumetric titrant (decolorized to sulfur in acids, converted to sulfate in bases).

  • Sodium Nitrite ($NaNO_2$):

    • Antidote for Cyanide poisoning.

    • Curing agent for meats and fish (enhances red color, preserves flavor with $NaCl$, and prevents bacterial growth).

  • Sodium Starch Glycolate:

    • Brand Name: Primojel®.

    • Superdisintegrant utilized in tablet formulations.

  • Monosodium Glutamate (MSG):

    • Brand Name: Ajinomoto®.

    • Flavor enhancer; excessive consumption causes Chinese Restaurant Syndrome.

• Potassium ($K$):

  • Synonym: Kalium.

  • Principal intracellular cation.

  • Deficiency State: Hypokalemia (resulting from severe thermal burns, persistent diarrhea, or prolonged diuretic use). Manifests clinical signs of severe muscle weakness and flaccid paralysis.

  • Pharmacologic Actions: Diuretic action, fundamental role in muscular contraction and cardiac nerve impulse conduction.

  • Potassium Acetate ($CH_3COOK$): Systemic and urinary alkalizer, diuretic, antacid.

  • Potassium Bicarbonate ($KHCO_3$): Systemic antacid, diuretic, electrolyte replenisher. Prolonged use carries a risk of hyperkalemia. Functions as a carbonating agent in Magnesium Citrate Oral Solution, USP.

  • Potassium Bitartrate ($KHC_4H_4O_6$):

    • Synonyms: Cream of Tartar, Argol, Acid Potassium Tartrate.

    • Naturally occurs in acidulous fruits (especially grapes).

    • Saline laxative; ingredient in baking powder to liberate $CO_2$ and raise dough.

  • Potassium Bromide ($KBr$): Central nervous system depressant, sedative. Used to prepare solid KBr pellets for Infrared (IR) spectroscopy.

  • Potassium Carbonate ($K_2CO_3$):

    • Synonyms: Potash, Pearl Ash, Salt of Tartar, Salt of Wormwood.

    • Basic pharmaceutical necessity, carbonating agent.

  • Potassium Chloride ($KCl$):

    • Salt of choice for intravenous potassium replenishment.

    • Key component in Ringer's Solution and Darrow's Solution ($KCl$, $NaCl$, and Sodium Lactate).

  • Potassium Hydroxide ($KOH$):

    • Synonyms: Caustic Potash, Lye Potash.

    • Extremely strong, corrosive base. Saponifying agent used specifically for the manufacture of soft soaps.

  • Potassium Iodide ($KI$):

    • Iodide salt of choice; expectorant and solubilizing agent for elemental Iodine.

    • Excessive or prolonged administration leads to Iodism (characterized by hyperlacrimation, excessive salivation, severe rhinitis, weakness, and acneiform skin eruptions).

    • Protects the thyroid gland by preventing goiter, blocks radioactive iodine uptake, used in preoperative preparation for thyroidectomy, and serves as the Drug of Choice (DOC) for cutaneous lymphatic sporotrichosis.

  • Potassium Nitrate ($KNO_3$):

    • Synonyms: Saltpeter, Salitre, Salt Prunelle.

    • Meat preservative and tooth-desensitizing agent in dentifrices.

  • Potassium Chlorate ($KClO_3$): Strong oxidizing agent; historically used as an antithyroid agent.

  • Potassium Permanganate ($KMnO_4$):

    • Synonym: Mineral Chameleon.

    • Powerful oxidizing agent; local anti-infective, topical antiseptic, and deodorant. Standard volumetric solution in permanganate titrations.

  • Monobasic Potassium Phosphate ($KH_2PO_4$):

    • Synonym: Sorensen's Potassium Phosphate.

    • Used in conjunction with dibasic potassium phosphate to treat severe hypercalcemia and act as a urinary acidifier.

  • Potassium Alum ($KAl(SO_4)_2 \cdot 12H_2O$):

    • Synonyms: Official Alum, Tawas.

    • Astringent, antiperspirant, deodorant, and local styptic.

  • Sulfurated Potash:

    • Synonyms: Liver of Sulfur, Hepar Sulfuris, Potassa Sulfurata.

    • Prepared by heating Potassium Carbonate with Sulfur.

    • Reagent in the preparation of White Lotion, USP (reacts with Zinc Sulfate to form a precipitate of Zinc Sulfide [$ZnS$]), which is applied topically to treat parasitic skin diseases.

• Ammonia ($NH_3$) and Ammonium Compounds:

  • Ammonia ($NH_3$): Synthesized via the Haber Process (catalytic combination of Nitrogen and Hydrogen gases under high pressure).

  • Ammonium ion ($NH_4^+$) behaves chemically as a hypothetical alkali metal.

  • Ammonium Hydroxide ($NH_4OH$) acts as a weak base compared to strong alkali metal hydroxides.

  • Household Ammonia contains $10\%\,\text{w/w}$ $NH_3$ ($16^\circ$ Baumé ammonia).

  • Ammonia Water (Dilute Ammonia Solution): Contains $9.5\%\text{--}10.5\%\,\text{w/w}$ $NH_3$. Used as a reflex respiratory stimulant and to neutralize local acid irritation from insect stings and jellyfish stings (such as the Portuguese man-of-war).

  • Aromatic Ammonia Spirit: Reflex respiratory stimulant containing Ammonium Carbonate, NF and Strong Ammonia Solution, NF.

  • Strong Ammonia Solution:

    • Synonym: Spirit of Hartshorn.

    • Contains $27\%\text{--}31\%\,\text{w/w}$ $NH_3$. Highly caustic liquid with intensely irritating vapors.

  • Ammonium Carbonate ($(NH_4)_2CO_3$):

    • Synonyms: Ammonia Crystal, Sal Volatile, Ammonium Sesquicarbonate, Preston's Salt, Hartshorn, Baker's Ammonia.

    • Consists of a mixture of ammonium bicarbonate ($NH_4HCO_3$) and ammonium carbamate ($NH_2COONH_4$).

    • Functions as an expectorant and reflex respiratory stimulant.

  • Ammonium Chloride ($NH_4Cl$):

    • Synonyms: Muriate of Hartshorn, Sal Ammoniac.

    • Systemic and urinary acidifier, expectorant, and diuretic.

  • Ammonium Alum ($NH_4Al(SO_4)_2 \cdot 12H_2O$): Tawas; astringent, styptic, antiperspirant, and deodorant.

  • Ammonium Acetate ($CH_3COONH_4$):

    • Synonym: Spirit of Mindererus.

    • Used as a pharmaceutical buffer component.

Antacid Properties and Classifications

• Classifications and Side Effects of Common Antacids:

  • Sodium Bicarbonate ($NaHCO_3$): Soluble antacid that causes systemic alkalosis and fluid retention.

  • Calcium Carbonate ($CaCO_3$): Potent, fast-acting antacid; causes hypercalcemia, rebound hyperacidity, constipation, and renal impairment (Burnett's Syndrome / Milk-Alkali Syndrome).

  • Magnesium Hydroxide ($Mg(OH)_2$): Rapid-acting antacid; induces osmotic diarrhea and systemic hypermagnesemia in patients with renal failure.

  • Aluminum Hydroxide ($Al(OH)_3$): Slow-acting antacid; causes severe constipation, intestinal obstruction, phosphate depletion, osteoporosis, and neurotoxicity (dialysis encephalopathy).

• Classification of Antacids by Onset of Action:

  • Rapid Onset: Magnesium Hydroxide, Magnesium Oxide, Calcium Carbonate.

  • Intermediate Onset: Magaldrate, Magnesium Carbonate.

  • Slowest Onset: Magnesium Trisilicate, Aluminum Compounds.

• Antioxidant Mechanisms and Examples:

  • Free Radical Scavengers (Primary Antioxidants): Propyl Gallate, Vitamin E (Tocopherol), Butylated Hydroxyanisole (BHA), Butylated Hydroxytoluene (BHT).

  • Reducing Agents (Selectively Oxidized Compounds): Vitamin C (Ascorbic Acid), Sulfites ($SO_3^{2-}$), Hypophosphites ($H_2PO_2^-$).

  • Chelating Agents (Prevent metal-catalyzed oxidation): Citric Acid, Tartaric Acid, Ethylenediaminetetraacetic Acid (EDTA) and its salts, Lecithin.

Industrial Processes and Acids

• Pharmaceutically Important Acids:

  • Boric Acid ($H_3BO_3$): Weak inorganic acid used as an eyewash buffer.

  • Hydrochloric Acid ($HCl$): Concentrated form contains $36.5\%\text{--}38\%\,\text{w/w}$ $HCl$ gas dissolved in water.

  • Nitric Acid ($HNO_3$): Concentrated solution contains $69\%\text{--}71\%\,\text{w/w}$ $HNO_3$.

  • Phosphoric Acid ($H_3PO_4$): Concentrated solution contains $85\%\text{--}88\%\,\text{w/w}$ H_3PO_4$.\n * **Sulfuric Acid (H_2SO_4$):** Concentrated solution contains$95\% ext{--}98\%\,\text{w/w}$$H_2SO_4$.

• Summary of Named Industrial Processes:

  • Solvay Process: Manufacture of Sodium Bicarbonate ($NaHCO_3$) and Sodium Carbonate ($Na_2CO_3$).

  • Haber Process: Industrial synthesis of Ammonia ($NH_3$) from $N_2$ and $H_2$ gas.

  • Contact Process: Production of concentrated Sulfuric Acid ($H_2SO_4$).

  • Guggenheim Process: Extraction and refining of nitrates.

  • Ostwald Process: Industrial synthesis of Nitric Acid ($HNO_3$) from ammonia.

  • Frasch Process: Mining and extraction of elemental Sulfur from underground deposits.

  • Dow Process: Extraction of Magnesium metal from seawater.

  • Lane Process / Messerschmidt Process: Production of pure Hydrogen gas ($99\%$ purity).

Group IB: Coinage Metals

• Group IB Overview:

  • Members: Copper ($Cu$), Silver ($Ag$), Gold ($Au$).

  • Known collectively as the Coinage Metals. Occur naturally in the uncombined free metallic state, or as complex chelates.

• Copper ($Cu$):

  • Latin Name: Cuprum.

  • Only reddish-colored metal.

  • Third most malleable metal; excellent conductor of heat (surpassed only by Silver and Gold) and electricity (surpassed only by Silver).

  • Oxidation States:

    • Cuprous ($Cu^+$ / $Cu^{1+}$): Insoluble in water; forms white precipitates, except for Cuprous Oxide ($Cu_2O$, red) and Cuprous Sulfide ($Cu_2S$, black).

    • Cupric ($Cu^{2+}$): Soluble in water; yields intensely blue solutions.

  • Essential trace element found in human respiratory chromoproteins, including Hemocyanin and Cytochrome Oxidase.

  • Pharmacologic Action: Protein precipitant, enhances the systemic utilization of Iron ($Fe$).

  • Toxicity Antidote: Penicillamine or BAL (British Anti-Lewisite / Dimercaprol).

  • Cupric Sulfate ($CuSO_4 \cdot 5H_2O$):

    • Synonyms: Blue Vitriol, Blue Stone, Roman Vitriol, Salzburg Vitriol.

    • Key component in Benedict's, Fehling's, and Barfoed's reagents for detecting reducing sugars.

    • Antidote for acute Phosphorus poisoning.

  • Cupric Acetoarsenite:

    • Synonym: Paris Green.

    • Potent insecticide.

  • Bordeaux Mixture: Mixture of Cupric Sulfate ($CuSO_4$) and Lime ($CaO$); used as an algaecide and fungicide in swimming pools and agriculture.

• Silver ($Ag$):

  • Latin Name: Argentum.

  • Very soft, highly ductile, and extremely malleable metal.

  • Fine silver ($99.9\%$ pure) is too soft for practical physical applications and is alloyed with other metals to increase mechanical strength.

  • Pharmacologic Actions: Protein precipitant, exhibits Oligodynamic Action (antimicrobial activity exerted by minute concentrations of heavy metal ions).

  • Toxicity: Argyria (permanent grayish-blue discoloration of skin and mucous membranes resulting from silver accumulation).

    • Antidote: Normal Saline Solution ($0.9\%\,\text{w/v}$ $NaCl$) or Sodium Chloride solution.

  • Silver Nitrate ($AgNO_3$):

    • Synonyms: Lunar Caustic, Lapis Infernalis (caustic pencil).

    • Water-soluble silver salt; active ingredient in indelible ink.

    • Topical agent for removal of warts; historically instilled as a $1\%$ ophthalmic solution into newborn eyes (Credé's prophylaxis for ophthalmia neonatorum).

  • Silver Proteinates Comparison:

    • Mild Silver Protein (Argyrol®): Contains $19\%\text{--}23\%$ elemental Silver. Used as an antiseptic for eyes.

    • Strong Silver Protein (Protargol®): Contains $7.5\%\text{--}8.5\%$ elemental Silver. Used as an antiseptic for ears and throat.

    • Colloidal Silver Protein (Collargol®): Contains $18\%\text{--}22\%$ elemental Silver. Used as a general germicide.

• Gold ($Au$):

  • Latin Name: Aurum.

  • Known as the "King of All Metals."

  • Most malleable metal and best overall conductor of electricity.

  • Precious, soft, extremely ductile metal.

  • Insoluble in most concentrated acids; dissolves only in the presence of:

    1. Aqua Regia: Solution consisting of $3$ parts Hydrochloric Acid ($HCl$) to $1$ part Nitric Acid ($HNO_3$).

    2. Selenic Acid ($H_2SeO_4$) or Cyanide solutions.

  • Toxicity: Gold Dermatitis.

    • Antidote: BAL (Dimercaprol / British Anti-Lewisite).

  • Purple of Cassius: Colloidal gold adsorbed onto stannic hydroxide ($Sn(OH)_4$).

  • Aurothioglucose (Solganal®): Injectable gold compound used in auto-immune conditions such as Rheumatoid Arthritis.

  • Gold Sodium Thiomalate (Myochrysine®): Injectable gold preparation for adult and juvenile rheumatoid arthritis.

Important Alloys

• Composition of Key Alloys:

  • Bronze: Copper ($Cu$) + Tin ($Sn$)

  • Brass: Copper ($Cu$) + Zinc ($Zn$)

  • Babbitt Metal: $20\%$ Antimony ($Sb$) + $80\%$ Tin ($Sn$)

  • Misch Metal: $30\%$ Iron ($Fe$) + $70\%$ Cerium ($Ce$)

  • Pewter: $20\%$ Lead ($Pb$) + $80\%$ Tin ($Sn$)

  • Solder: $50\%$ Lead ($Pb$) + $50\%$ Tin ($Sn$)

  • Rose Metal: $25\%$ Lead ($Pb$) + $25\%$ Tin ($Sn$) + $50\%$ Bismuth ($Bi$)

  • Gun Metal: $10\%$ Tin ($Sn$) + $90\%$ Copper ($Cu$)

  • Lithopone: $30\%$ Zinc Sulfide ($ZnS$) + $70\%$ Barium Sulfate ($BaSO_4$)

  • Raney Nickel: Nickel ($Ni$) + Aluminum ($Al$)

  • Devarda's Alloy: Zinc ($Zn$) + Aluminum ($Al$) + Copper ($Cu$)

  • Steel: Iron ($Fe$) + $3\%$ Carbon ($C$)

  • Monel Metal: Nickel ($Ni$) + Copper ($Cu$)

  • German Silver: Zinc ($Zn$) + Copper ($Cu$) + Nickel ($Ni$)

  • Basham's Alloy / Mixture: Iron ($Fe$) + Ammonium Acetate