PCQA111 Periodic Table of Elements Group VIA and VIB PDF

OUR LADY OF FATIMA UNIVERSITY College of Pharmacy PCQA111 WEEK 14 At the end of this unit, the students are expected to:  Demonstrate a comprehensive understanding of the chemistry of metals, non-metals and metalloids. 2 ▪ Elements ▪...

OUR LADY OF FATIMA UNIVERSITY College of Pharmacy PCQA111 WEEK 14 At the end of this unit, the students are expected to:  Demonstrate a comprehensive understanding of the chemistry of metals, non-metals and metalloids. 2 ▪ Elements ▪ Properties ▪ Identification Tests ▪ Compounds and Their Uses 3  Read the available learning references before the discussion.  Search for the meaning of the following terminologies.  Listen and participate in the board discussion. 4 5 6  Sulfur is also a very It occurs on the earth’s common element and was crust as a free element and known to the ancients as in combined form as metal brimstone, that is- “burning sulfides and sulfates stone”. Oxygen is the most abundant element in the earth’s crust. Selenium and tellurium occur much less abundantly than sulfur. Polonium occurs only in the They are found along with sulfur form of radioisotopes as a in metal sulfides and are recovered in some quantity from result of the decay of the lead and copper refining actinide elements processes. What are the elements under group VIA? 8 9 Oxygen  “Dephlogisticated Air” (Priestly)  “Empyreal Air” (Scheele)  Most abundant element  Non metallic element  2nd most electronegative  Essential of all elements 10 3 Allotropes of Oxygen 11 Oxygen Requirements: 1. Anoxic-inadequate O2 tension in air 2. Anemic-decrease hemoglobin 3. Histotoxic-tissue or cell oxidation 4. Stagnant-blood circulation is retarded USE:  Treatment of hypoxia (lack of O2) 12 Oxygen Gas  Administration - tubes, masks, tents  Diluent for anesthetic agent 13  “Brimstone”  “Burning Stone”  Shulbari-enemy of Copper 14 15  Rhombic – ex. Rock sulfur, roll sulfur, flower of S  Monoclinic – needle like crystal  Mobile – straw-colored liquid  Viscous – thick and sticky like molasses  Plastic or Amorphous– rubbery, plastic mass  Sulfur Vapor – form when sulfur is heated above 1000 degrees Celsius 16 Forms of Sulfur  Precipitated Sulfur -milk of sulfur, fine, component of cream, ointment  Sublimed sulfur -flower of sulfur, azufre, coarse, cathartic 17 USES:  Preparation of scabicidal & keratolytic ointments & lotions  Stimulant cathartic  Stimulant in alopecia  Fumigant(SO2)  Depilatory (sulfides)  Keratolytic (SrS)  Antiseborrheic(CdS) 18 Sulfuric Acid  “Oil of Vitriol”  Sulfonating agent  Dehydrating agent Sodium Thiosulfate  Use in photography  For ringworm  Antidote for cyanide and Iodine poisoning 19 Hydrogen Sulfide  Aitch-tu-es- gas  Reducing agent, precipitating agent of metal ions  Rotten egg odor Sulfur Ointment  Precipitated sulfur  Liquid petrolatum  White ointment  Scabicide  parasiticide 20  Selenium  “ moon”  Trace element  Anti-oxidant  Synergistic with Vitamin E  Too toxic when taken internally  Use in the manufacture of photocopying machine  Catalyst in Nitrogen determination 21 Selenium Sulfide  Active constituent of Selsun Blue  Antiseborrheic 22  A radioactive isotope as a result of decay of actinide elements 23 24 S2-  1 Dilute H2SO4 evolves H2S characterized by its odor of rotten egg.  Pb(C2H3O2)2: black ppt of PbS SO32-  Dilute H2SO4 evolves SO2 characterized by its odor of burnt sulfur.  KMnO4 or I2 solutions: the solutions are decolorized SO42-  Dilute H2SO4: no reaction  BaCl2: white ppt of BaSO4, which is insoluble in all acids. S2O32-  1Dilute H2SO4 evolves SO2 with the precipitation of yellow S.  2 KMnO4 or I2 solutions: the solutions are decolorized. 27 28  Compounds in which chromium exhibits a 2+ oxidation state are good Chromium forms compounds with reducing agents (since they are oxidation states of 2+, 3+ and 6+. readily oxidized to 3+); compounds Molybdenum and tungsten form such as dichromates (Cr2O72-) having compounds in which they exhibit oxidation states of 2+ through 6+. For chromium the 6+ oxidation number are readily most stable oxidation state is 3+. reduced to the 3+ state and are thus good oxidizing agents. GROUP VI-B THE CHROMIUM SUBGROUP The oxides form a series of compounds such as the chromates, The elements of group VI-B form the molybdates, etc., Chromium (III) oxides of which those of higher hydroxide is amphoteric salt or will molecular weight are acidic. dissolve in excess of alkali to form chromite (CrO2-). What are the elements under group VIB? 30 31  Chromium  Cr+2-green  Cr+3-blue  CrO4-2-yellow  Cr2O7-2-orange SOURCE:  chrome iron ore 32  Chromium  Trace element  Glucose tolerance factor  Increases insulin sensitivity  Found in brown sugar & butter  Salts are destructive to tissues DEFICIENCY:  mimics Diabetes Mellitus K2Cr2O7  Powerful oxidizing agent 33  Essential trace element  Cofactor of enzyme that are flavin dependent  Use in nitrogen fixation involve in bacterial fixing of atmospheric nitrogen  MoO+FeSO4 (Mol-Iron®) 34  Radioactive element  Discovered by Becquerel  Manufacture of atomic bombs 35 Uses  Use in making special steel alloys,  Filaments of electric lamps  as the anti-cathode in X-ray tubes. 36 37 Cr3+  NaOH: grayish green ppt of Cr(OH)3 which will dissolve in excess of the alkali to form a green solution, NaCrO2. When an oxidizing agent like Na2O2 is added, it turns yellow due to Na2CrO4. CrO42-  BaCl2: yellow ppt of BaCrO4  AgNO3: brownish red ppt of Ag2CrO4  Perchromic Acid Test or Vanishing Blue Test  H2O2 and ether ➔ blue ethereal layer due to perchromic acid ◉ https://www.youtube.com/watch?v=HxnDNs Fra5o 39  2. It is 1. Enumerate radioactive 3. Enumerate chemical isotope as a identification properties of result of decay tests for Group VIA. of actinide elements group VI B. 1. Please take Quiz #__ on _______. You have 20 minutes to complete this quiz. ▪ Questions : 20 questions ▪ Time Limit : 20 minutes 41  Qualitative Analysis by Esmarch S. Gilreath Remington: The Science and Practice of Pharmacy 21st Edition 42 ANY QUESTIONS? You can find me at: [email protected],ph 43