Module 5

• Peroxide anion


  O2 2-
• α-tin


  • Nonmetallic
• β-tin


  • Metallic
• Protium


  Most abundant
• Deuterium


  Reacts slower than protium
• Tritium


  Least abundant, found in trace amounts, half-life of 12.3 years
• Isotopic labeling


  One or more hydrogens are targeted and replaced by either deuterium or tritium
• Cracking


  The process of converting high-molecular weight hydrocarbons from petroleum into lower-molecular weight hydrocarbons that are more suitable for gasoline, diesel, etc.
• Ionic hydrides


  • With group 1 or 2 elements (less electronegative elements); hydrogen acquires an electron
• Metallic hydrides


  • With transition metals
• Interstitial holes


  • Empty areas located between the sites occupied by metal atoms
• Molecular hydrides


  • With nonmetals and metalloids; exist as gasses or liquids under standard conditions
• Carbon monoxide


  Formed when carbon or hydrocarbons are burned with limited supply of oxygen, functions as a Lewis base
• Carbon dioxide


  Produced when carbon-containing substances are burned in the presence of excessive amounts of oxygen, greenhouse effect
• Catenation


  Ability to bond with other carbon atoms, leading to formation of several compounds containing chains of carbon atoms
• Graphite


  • sp2-hybridized, soft, black, slippery solid
• Diamond


  • sp3-hybridized, clear, hard solid, takes million years to be converted to graphite
• Calcium carbide


  Ripening agent for fruits, kalburo
• Interstitial carbides


  • Carbon atoms occupy open spaces in the metal lattice
• Covalent carbides


  • Do not involve metals
• Carbonic acid


  Formed when carbon dioxide is dissolved in water, weak diprotic acid, responsible for the sharp, slightly acidic taste of carbonated beverages
• Bicarbonate


  Products of partial neutralization, amphoteric in water
• Carbonate


  Products of complete neutralization, much stronger bases than bicarbonates, commonly found as minerals
• White phosphorus


  • Very unstable due to strained bonds, can spontaneously combust upon exposure to air, commonly stored in water to prevent exposure to air
• Red phosphorus


  • More stable due to the linked network of phosphorus atoms, does not spontaneously combust upon contact with air, can be obtained by heating white phosphorus to 400 C in the absence of air
• Violet phosphorus


  • Most stable along with black phosphorus, exists in the form of a polymer with pentagonal tubes
• Black phosphorus


  • A sheet similar to graphene
• Phosphorus trihalides


  Reacts with water to form phosphorous acid H3PO3 and a hydrohalic acid HX
• Phosphorus pentahalides


  Reacts with water that produces phosphoric acid H3PO4 and a hydrohalic acid
• Oxy compounds


  Most significant phosphorus derivatives
• Boron-10


  • Commonly used in boron neutron capture therapy, known to be a good absorber of neutrons
• Boron-11


  • More attracted to tumor sites than the healthy sites
• Borane


  Contains boron and hydrogen only, do not occur in nature, high reactive when exposed to air which releases large amounts of energy
• BH3


  Spontaneously flammable in air, simplest borane dimerizes to form diborane B2H6; a lewis acid-base reaction wherein B–H bonding pair can be donated to another molecule of BH3
• Bridging hydrogens


  • Hydrogens having two bonds around it, can satisfy the deficiency of valence electrons between the two BH3 molecules that dimerized
• Closo–


  • BnHn2-, bigger closo borane, the more stable it is in solution, appear as triangulate polyhedra with n corners
• Nido–


  • BnHn4-, removal of one corner from the closo– framework yields nido structure
• Arachno–


  • BnHn6- two corners are removed from the closo– framework