24.2 part 2pptx


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24.2 part 2pptx

  1. 1. 24.2 sec 2Nitrogen Family- Oxygen Family<br />
  2. 2. Nitrogen and Group 5<br />N is a nonmetal, gas at rm temp; essential for living things<br />80% of air is N2, but most living things cannot use pure nitrogen- bacteria “fix” nitrogen into usable form<br />N2 is commercially obtained 2 ways, both from air: <br /> 1) fractional distillation ( nitrogen boils off first)<br /> 2) Air is moved over hot coke ( C) and oxygen is removed and forms CO2leaving nitrogen<br />
  3. 3. N2 is colorless, odorless, tasteless, slightly soluble in water <br />Used to make NH3, ammonia in Haber process (pg 715), and nitric acid<br />Ammonia- strong odor, colorless gas, soluble in water, slightly basic; used in cleaning products, fertilizers, refrigerant<br />Nitric acid ( can be made from ammonia)-used in etching, fertilizers, dyes and explosives<br />Nitrogen and Group 5<br />
  4. 4. N video<br />N video<br />By lennox_mcdough<br />
  5. 5. P- nonmetal; important in living things (DNA, bones, teeth, ATP)<br />Found as phosphate rock<br />In pure form- 2 types of P- red and white<br /> white is very reactive and stored under water; red is less reactive-used in matches<br />Nitrogen and Group 5<br />
  6. 6. Arsenic, Bismuth, Antimony<br />Arsenic, Bi and antimony occur in nature as sulfide minerals<br />Sb and Bi expand when heated- used in alloys ( printing presses)<br />Bi video<br />Sb video<br />Ar video<br />
  7. 7. Oxygen and Group 6A<br />O and S nonmetals; Se and Te are metalloids; Po is a radioactive, metal that occurs in small amounts<br />
  8. 8. Oxygen<br />There are more oxygen atoms in the Earth’s crust, surface waters and atmosphere than atoms of any other element.<br />Molecular oxygen (O 2)makes up 23% by mass of the atmosphere.<br />Oxygen in compounds make up 46% by mass of the crust and upper mantle.<br />In surface waters, oxygen accounts for 86% by mass.<br />
  9. 9. Oxygen production<br />Industrially, oxygen is obtained by liquefying and fractionally distilling air.<br />Worldwide production of oxygen is almost 2 x 1011 pounds each year. This is only 10-5% of the oxygen in the atmosphere.<br />Molecular oxygen is continuously being<br /> made via photosynthesis by plants that<br /> require carbon dioxide.<br />Animals breathe in oxygen and breathe out<br /> carbon dioxide.<br />
  10. 10. Oxygen use<br />The major industrial use is in the production of steel. This accounts for 65-85% of production.<br />Large quantities of oxygen are also used to produce titanium(IV) oxide, a white pigment.<br />Oxygen is also used as an oxidizing agent to power the space shuttle, for sewage treatment and various industrial processes.<br />It also is used in medicine. <br />
  11. 11. Physical properties of O2<br />O2 is a colorless, odorless, tasteless gas.<br />Solubility.<br />Only slightly soluble in water.<br />Less soluble in salt water than fresh water.<br />Increasing temperature will decrease solubility in water.<br />It is paramagnetic (weakly magnetic)<br />
  12. 12. Ozone<br />Ozone, O3, is an allotrope of molecular oxygen.<br />It is prepared by electrical discharge or UV light on molecular oxygen.<br /> 3O2 + 2O2 (g)<br />Ozone is a diamagnetic blue gas with a characteristic odor. Concentrations as low as 0.01 ppm can be detected by odor.<br />UV or <br />silent electrical discharge<br />GOOD UP HIGH<br />BAD NEARBY<br />
  13. 13. Ozone<br />Ozone is unstable and very reactive, <br /> Catalysts and UV light cause it to decompose.<br /> 2O3 (g) 3O2 (g)<br />It is also a more powerful oxidizing agent that molecular oxygen. In acidic solutions, it is one of the most powerful oxidizing agents known.<br /> O3 (g) + 2H+ + 2e- O2 (g) + H2O (l) Eo = +2.07 V<br />catalyst or UV<br />
  14. 14. Ozone<br />Atmospheric ozone.<br />Ozone strongly absorbs UV radiation in the 220-290 nm range.<br />The ozone layer is stratospheric-level O3. It protects the Earth’s surface from the Sun’s intense UV radiation.<br />Tropospheric level O3, however, is harmful. It contributes to smog formation and causes rubber to crack.<br />GOOD UP HIGHBAD NEARBY<br />
  15. 15. Ozone<br />Ozone as a disinfectant.<br />O3 is now being used in hospitals, hotels and commercial laundries.<br />It is also used to purify drinking water.<br /> Advantage<br /> After reaction, only O2 remains unlike when Cl2 is used. Chlorine can form chlorocarbons.<br />Disadvantage<br /> No residual protection. Since it rapidly decomposes, there is no protection after water treatment.<br />
  16. 16. Chemical Properties of O<br />When substances combine w/oxygen the process is called oxidation, mostly the products are oxides<br />Usually this occurs when you heat the elements in the presence of oxygen<br />Oxides of metals are usually solids, and can form a basic water solution<br />Oxides of nonmetals can be a solid, liquid or gas and tend to form acidic water solutions<br />
  17. 17. Oxygen video<br />
  18. 18. Sulfur<br />S is a yellow, tasteless, odorless, brittle solid<br />Elemental sulfur has more allotropes than any other elements.<br />The S-S bond is<br />the third strongest<br />single bond between<br />the same kind of<br />atoms.<br />At room temperature,<br />the most common<br />form is rhombic,<br />consisting of <br />eight member rings.(S8)<br />
  19. 19. Sulfur<br />When sulfur is heated, the packing of the S8 molecules changes around 96 oC.<br />Another form of sulfur is monoclinic sulfur. It is stable between 96-119 oC.<br />When liquid sulfur is heated (160-195 oC), it polymerizes into chains up to 200 000 S long.<br />160-195 oC<br />160-195 oC<br />
  20. 20. Sulfur<br />When liquid sulfur polymerizes, its viscosity increases by a factor of at least 10 000.<br /> This is because the long chains tend to get tangled up in each other.<br />
  21. 21. Sulfur reactivity<br />Sulfur is quite a reactive element.<br />It will react will all elements except nitrogen, tellurium, iodine, iridium, platinum, gold and the noble gases.<br />Heating may be necessary to bring about a reaction.<br />Compounds of all elements except the noble gases with sulfur are known.<br />Although it is reactive, sulfur can be found in nature in free as well as combined form.<br />
  22. 22. Sulfur production<br />Compressed<br />hot air<br /> Free sulfur occurs in rock over salt domes near the coast of East Texas and Louisiana and under the Gulf of Mexico. It is mined by the Frasch process.<br />Sulfur<br />Superheated<br />water<br />Frasch process<br />Molten<br />Sulfur<br />
  23. 23. Sulfuric acid and sulfates<br />Sulfuric acid<br />It is the cheapest strong acid.<br />Concentrated sulfuric acid is an oxidizing agent -- but only when hot.<br /> Cu (s) + 2H2SO4 (conc) CuSO4 (aq) + 2H2O (l) + SO2 (g)<br />When cold, it will not oxidize copper.<br />It is such a powerful dehydrating agent, it can char many organic substances (sugar dehydration-products are C and water)<br />heat<br />Little Tommy was my friend.<br /> Alas, he is no more<br />What little Tommy thought was H2O,<br /> Was H2SO4<br />
  24. 24. Produced by the contact process-Sulfur is burned in air to form sulfur dioxide, then sulfur dioxide combines w/more oxygen in presence of vanadium(V)oxide to form sulfur trioxide; sulfur trioxide combines w/water to form sulfuric acid<br />Dilute sulfuric acid combines w/ metals, oxides, hydroxides or carbonates to form sulfate salts<br />Sulfuric acid and sulfates<br />
  25. 25. Sulfuric acid and sulfates<br /> Some important sulfates<br />Aluminum sulfate<br /><ul><li>Al2(SO4)3
  26. 26. Produced from Al2O3.2H2O (bauxite)
  27. 27. Used to treat water
  28. 28. Used to size paper - fill pores.</li></ul>Ammonium sulfate<br /><ul><li>(NH4)2SO4
  29. 29. Produced by reaction of H2SO4 and NH3
  30. 30. Used in fertilizers.</li></li></ul><li>Oxides of sulfur<br />A number of oxides are known to exist but SO2 and SO3 are the most stable and important.<br />Sulfur dioxide - SO2<br /> Colorless gas with a sharp odor; harmful to animal and plant life; produced by combustion of sulfur-containing fuels, volcanoes and air oxidation of marsh gases.<br />Is oxidized to SO3 by air oxidation.<br />
  31. 31. Oxides of sulfur<br />Sulfur trioxide - SO3<br />It is a liquid under ordinary conditions. Difficult to handle because it reacts vigorously with many materials. It is an anhydride of sulfuric acid.<br /> SO3 (g) + H2O (l) H2SO4 (l)<br />It, along with NO2, HCl, SO2, accounts for the acidity of acid rain. <br />
  32. 32. S video<br />