Title ريبورتات كامله Inorganic lab 1.pdf ✅

Kuwait University. Chemistry Department. Inorganic Chemistry Lab (Chem. 338). Exp 1: Synthesis of Potassium TRIOXALATOALUMINATE (III) Trihydrate K3(Al(C2O4)3).3H2O
Mariam Rashed Alnabhan. 2151112291 Jan21, 2020 Abstract: • In this experiment we where able to prepare a Potassiumtrioxalatoaluminate Trihydrate complex. And we have been able to analysis the complex. And calculating the percentage yield and purity by potentiometric titration using combined redox electrode vs KMnO4 (0.02M). Introduction : • The thermal behavior of K3Al(C2O4)3·mH2O was investigated by means of thermogravimetry, differential thermal analysis, differential scanning calorimetry, infrared spectral analysis, evolved gas analysis and high temperature X-ray diffraction. The dehydration proceeds via the intermediate 2- and 0.75-hydrates (room temperature to 120°C). The existence of the 3-hydrate could not be confirmed. On increasing the temperature, anhydrous potassium trioxalatoaluminate decomposes into potassium oxalate, potassium carbonate and alumina (320–435°C). The potassium oxalate decomposition (435- 475°C) is overlapped by the formation of KAlO2 from potassium carbonate and alumina; the procedural final temperature of the latter process is dependent on the CO2 partial pressure. After the thermal decomposition of the excess K2CO3 present, KAlO2 is the final solid product.
Potassiumtrioxalatoaluminate Trihydrate complex : • Molecular formula : K3[Al(C2O4)3].3H2O • Structural formula : • Proprieties of the complex: 1. Octahedral structure. 2. SP3 d2 Hybridization. 3. White or colorless. 4. The ligand is Oxalato C2 O4 2- is bidentate ligand. 5. Very stable complex. 6. Its optically active. (no plane of symmetry) 7. It has two pairs of enantiomers. 8. Its soluble in water. 9. The complex is one type of alums. • Optically active : Definition capable of rotating the plane of vibration of polarized light to the right or left —used of compounds, molecules, or atoms (no plane of symmetry). Optically active is the rotation of the orientation of the plane of polarization about the optical axis of linearly polarized light as it travels through certain materials. Optical activity occurs only in chiral materials, those lacking microscopic mirror symmetry. Unlike other sources of birefringence which alter a beam's state of polarization, optical activity
can be observed in fluids. This can include gases or solutions of chiral molecules such as sugars, molecules with helical secondary structure such as some proteins, and also chiral liquid crystals. It can also be observed in chiral solids such as certain crystals with a rotation between adjacent crystal planes (such as quartz) or metamaterials. Rotation of light's plane of polarization may also occur through the Faraday effect which involves a static magnetic field, however this is a distinct phenomenon that is not usually classified under "optical activity." The rotation of the plane of polarization may be either clockwise, to the right (dextrorotary — d-rotary), or to the left (levorotary — l-rotary) depending on which stereoisomer is present (or dominant). For instance, sucrose and camphor are d-rotary whereas cholesterol is l-rotary. For a given substance, the angle by which the polarization of light of a specified wavelength is rotated is proportional to the path length through the material and (for a solution) proportional to its concentration. The rotation is not dependent on the direction of propagation, unlike the Faraday effect where the rotation is dependent on the relative direction of the applied magnetic field. Optical activity is measured using a polarized source and polarimeter. This is a tool particularly used in the sugar industry to measure the sugar concentration of syrup, and generally in chemistry to measure the concentration or enantiomeric ratio of chiral molecules in solution. Modulation of a liquid crystal's optical activity, viewed between two sheet polarizers, is the principle of operation of liquid-crystal displays (used in most modern televisions and computer monitors). • Enantiomers : An enantiomer is one of two stereoisomers that are mirror images of each other that are non-superposable (not identical), much as one's left and right hands are mirror images of each other that cannot appear identical simply by reorientation. A single chiral atom or similar structural feature in a compound causes that compound to have two possible structures which are non-superposable, each a mirror image of the other. Each member of the pair is termed an enantiomorph (enantio = opposite; morph =
form); the structural property is termed enantiomerism. The presence of multiple chiral features in a given compound increases the number of geometric forms possible, though there may still be some perfect-mirror- image pairs. (S)-(+)-lactic acid (left) and (R)-(–)-lactic acid (right) are nonsuperposable mirror images of each other. • Alums : An alum is a type of chemical compound, usually hydrated double sulfate salt of aluminum with the general formula XAl(SO4)2·12H2O, where X is a monovalent cation such as potassium or ammonium. By itself, "alum" often refers to potassium alum, with the formula KAl(SO4)2·12H2O. Other alums are named after the monovalent ion, such as sodium alum and ammonium alum. The name "alum" is also used, more generally, for salts with the same formula and structure, except that aluminium is replaced by another trivalent metal ion like chromium(III), and/or sulfur is replaced by other chalcogen like selenium. [1] The most common of these analogs is chrome alum KCr(SO4)2·12H2O.In most industries, the name "alum" (or "papermaker's alum") is used to refer to aluminium sulfate Al2(SO4)3·nH2O, which is used for most industrial flocculation. In medicine, "alum" may also refer to aluminium hydroxide gel used as a vaccine adjuvant.