Solubility rules usually soluble

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Solubility rules usually soluble

  1. 1. Solubility rules-usually soluble<br />Apply rules in order<br />Acids (except long chain organics)<br />SA: HCl, HBr, HI, HNO3, H2SO4, HClO4<br />SA completely dissociate<br />All Na+, K+, NH4+, NO3-, C2H3O2-<br />Most Cl-, Br-, I- (some exceptions)<br />Most SO4-2 (some exceptions)<br />
  2. 2. Solublity rules –mostly insoluble<br />5. Most S-<br />6. Most OH- CO3-2 SO3-2 PO4-3<br /> Strong Bases: Li, Na, K, Rb, Cs OH<br /> Ca, Sr, Ba, Ra (OH)2<br /> strong bases completely dissociate<br />7. Gases <br />Elemental gases very slightly soluble<br />CO2 H2S SO2 slightly soluble<br />(bubble out of solution)<br />H2SO3 and H2CO3 break down in acidic soln<br />See more detailed rule<br />Handouts<br />Book chart<br />
  3. 3. Another way to look at the rules follows<br />These are only for the most common compounds – there are obviously more rules (and exceptions!!!)<br />
  4. 4. General Solubility rulesusually soluble<br />Soluble Compounds<br />Salts of Na+ K+ NH4+<br />Salts of Cl- Br- I-<br />Salt of F-<br />Salts of NO3- ClO3- ClO4- and C2H3O2-<br />Salts of SO4-2<br />Exceptions<br />Ag+ Hg2+2 Pb+2<br />Mg+2 Ca+2 Sr+2 Ba+2 Pb+2<br />Sr+2 Ba+2 Pb+2<br />
  5. 5. General solubility rulesgenerally insoluble<br />Insoluble compounds <br />Salts of<br />CO3-2<br />PO4-3<br />C2O4-2 (oxalate)<br />CrO4-2<br />S-2<br />OH-1<br />O-2<br />Exceptions<br />Salts of NH4+ and all the alkali metals (Group IA metals)<br />
  6. 6. Medical applications<br />Kidney stones are often calcium salts of slightly soluble compounds (we classified them as insoluble)<br />Phosphates<br />Carbonates<br />Oxalates<br />Calcium oxalate crystals are needle like and would be extremely painful to excrete!! Whereas the phosphates and carbonates aren’t needle-like<br />
  7. 7. Other medical applications<br />A lot of drugs have poor solubilities as neutral molecules –<br />Many of the drug molecules have acidic or basic groups<br />If you react the acid molecules with NaOH – you can produce the sodium salt - usually with better solubility<br />If you react the basic molecules (the amines) with HCl – you produce the chloride salt and usually increase the solubility<br />
  8. 8. Example of these drugs<br />Naproxen sodium (or sodium naproxen) the drug in Alleve – acid group reacts with NaOH to eliminate water leaving naproxen as an anion<br />Naproxen-COOH + NaOH NaproxenCOO-Na+ + H2O<br />Pseudoephedrine hydrochloride:a decongestant <br />PseudoephedrineNH2 + HCl pseudoephedreinNH3+Cl-<br />

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