6A 6B

• CrO 4 2- BaCl 2 : yellow ppt of BaCrO 4 AgNO 3 : brownish red ppt of Ag 2 CrO 4 Perchromic Acid Test or Vanishing Blue Test H 2 O 2 and ether  blue ethereal layer due to perchromic acid.
• Oxygen, also known as Empyreal Air, Dephlogisticated Air, Yne, and Acid former, is the most abundant element and is used in the treatment of hypoxia/asphyxia.
• Sulfur, also known as Sufra, is a crude furnace source and is used in the preparation of scabicidal and keratolytic ointment or lotion, as a stimulant cathartic, depilatory agent, fumigant, and anti-dandruff.
• Sulfur varieties include amorphous sulfur, liquid sulfur, heating sulfur at 160-180 degrees Celcius, plastic sulfur, and precipitated sulfur/lac sulfur/milk sulfur.
• Sulfuric Acid, also known as Oil of Vitriol, is a sulfonating and dehydrating agent, and is used in photography, for ringworm, and as an antidote for cyanide and Iodine poisoning.
• Selenium Disulfide, SeS2, is used in SelsunBlue®(2.5%).
• Brand name: MOL-IRON.
• Group VIB: Chromium Subgroup
• When an oxidizing agent like Na 2 O 2 is added, it turns yellow due to Na 2 CrO 4.
• KMnO 4 or I 2 solutions: the solutions are decolorized
• Group VIB: Tungsten
• Uranium was discovered by Becquerel and is a radioactive element used for the manufacture of atomic bombs.
• BaCl 2 : white ppt of BaSO 4 , which is insoluble in all acids
• Seaborgium is an artificial chemical element with atomic number 106 and the symbol Sg in the periodic table.
• Compounds in which chromium exhibits a 2+ oxidation state are good reducing agents (since they are readily oxidized to 3+); compounds such as dichromates (Cr 2 O 7 2- ) having 6+ oxidation number are readily reduced to the 3+ state and are thus good oxidizing agents
• The oxides form a series of compounds such as the chromates, the molybdates, etc.
• Group VIB: Uranium
• Seaborgium is presently used for research purposes and its biological use is yet to be known.
• For chromium the most stable oxidation state is 3+
• 2 KMnO 4 or I 2 solutions: the solutions are decolorized
• Molybdenum and tungsten form compounds in which they exhibit oxidation states of 2+ through 6+
• Pb(C 2 H 3 O 2 ) 2 : black ppt of PbS SO 3 2- Dilute H 2 SO 4 evolves SO 2 characterized by its odor of burnt sulfur
• The elements of group VI-B form oxides of which those of higher molecular weight are acidic
• Group VIB: Molybdenum
• Chromium (III) hydroxide is amphoteric salt or will dissolve in excess of alkali to form chromite (CrO 2 - )
• Molybdenum Oxide is used as a hematinic.
• Molybdenum is an essential trace element and a co-factor enzyme.
• Chromium forms compounds with oxidation states of 2+, 3+ and 6+
• Identification tests of the ions include: Cr 3+ in NaOH: grayish green ppt of Cr(OH) 3 which will dissolve in excess of the alkali to form a green solution, NaCrO 2.
• S 2 O 3 2- Dilute H 2 SO 4 evolves SO 2 with the precipitation of yellow S
• Uranium has no pharmaceutical use.
• Tungsten is used in making special steel alloys and filaments of electric lamps as the anti-cathode in X-ray tubes.
• Tellurium, a metalloid, has a characteristic metallic luster, but can be pulverized to form a gray powder.
• Polonium, discovered by Marie Curie in 1898, along with Radium, is used in cancer treatment.
• Identification tests of the ions include S2- dilute H2SO4 evolving H2S characterized by its odor of rotten egg.