Halogens

• Halogens

  “The producer of sea salt” or “Salt-forming”
• Pseudohalogens

  CN, CNO, SCN, N3
• Fluorine

  • Most electronegative element
  • Super halogen (Linus Pauling)
  • Toxicity: Fluorosis
• Manifestation of Fluorine Toxicity

  • Mottled Enamel
  • Abnormal Bone Growth
• Cryolite

  Na + Al + F
• Sodium Fluoride (NaF)


  Anticariogenic at 2%
• Stannous Fluoride (SnF2)


  Anticariogenic at 8%
• Sodium Monofluorophosphate (Na2FPO3)

  Anticariogenic
• Dichlorodifluoromethane (CCl2F2)

  • Also known as Treon
  • Refrigerant
• Chlorine

  Dephlogisticated Muriatic Acid
• Chloros


  Greenish-Yellow
• Chlorides are precipitated with AgNO3
• Chloride is the most abundant extracellular anion
• Hypochlorite (ClO- )

  • Bleaching Agent
  • Oxidizing Agent
• Hydrochloric Acid (HCl)

  • Muriatic Acid (36.5-38% w/w)
  • Treatment for Achlorhydria (diluted)
• Bromine

  • Greek meaning: Stench
  • Dark reddish-brown fuming liquid with suffocating odor
  • Quickly attacks the skin to cause burn that is slow to heal. (Ammonia prevents it action)
• Use of Bromine

  Sedative/depressant
• Poisoning of Bromine

  Bromism
• Principal Manifestation of Bromine

  Skin eruption, Psychosis, Weakness, Headache
• Antidote for Bromism 


  NaCl and NH4Cl
• Bromine 10th N solution

  • AKA: Koppeschaar’s solution
  • Assay of phenols and related compounds
• Iodine

  • Greek meaning: Iodos (Violet-colored)
  • Most metallic halogen
  • Oldest germicide still used today
• Uses of Halogens:

  • Expectorant
  • Anti-fungal
  • Antibacterial (1:5000 or 0.02%) greater antibacterial activity versus chlorine and bromine of the same strength; same strength as KMnO4
• Deficiency if Iodine

  Goiter
• Toxicity of Iodine

  Iodism
• Antidote for Iodine

  Corn starch, Sodium thiosulfate
• Iodine Solution

  2% iodine in water + NaI (solubilizing agent; prevents precipitate)
• Phenolic Iodine Solution

  • AKA: Bolton’s Solution
  • Use: Antibacterial and irritant
• Strong Iodine Solution

  • AKA: Lugol’s Iodine
  • 5% iodine with KI in water
• Iodine Tincture

  Disinfectant (2% iodine: 50% alcohol with Na I)
• Povidone-Iodine (Betadine)

  • Iodine – Iodophore (Surfactant + Iodine); This doesn’t dissolve in H2O
  • Polyvinylpyrrolidone (Surfactant)
• Astatine

  • Only metallic and synthetic halogen resembling iodine
  • Only radioactive halogen
  • Half-life 8.1 hours (Rarest element)