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