Draw an electrolytic cell in which Mn2+ is reduced to Mn and Sn is oxidized to Sn2+. Label the anode and cathode, indicate the direction of electron flow, and write an equation for the half reaction occurring at each electrode. What minimum voltage is necessary to drive the reaction?
Chem 115 Week Five Notes Covalent Bond: sharing of electrons, low electronegativity difference Single bond: sharing of two electrons Double bond: sharing of four electrons Triple bond: sharing of six electrons Cannot “give” electrons as seen in ionic salts, or bonds Central atom: the atom which all other atoms in molecule bond to Nonpolar Bonds: 0.0 0.2 Polar Bonds: 0.31.4 Ionic Bonds: >1.5 Octet Rule: Number of valence electrons equals group # for main group elements Octet= 8 bonding valence electrons Driving force to “fill” octet Derived from electron configuration e.g. 1s2, 2s2, 2p2 4 valence electrons for carbon 1s2, 2s2, 2p4 6 valence electrons for oxygen n=2 is valence electrons Alkali metal, M has an outer shell configuration of ns1 Halogen (group 7) has an outer shell configuration of ns2, np5 7 valence electrons Unshared electrons: lone pairs Shared electrons: bonding electrons E.g. Cl2 has 3 lone pairs each, with one electron used for bonding ( ClCl) Rules for Central Atom: 1. Written first in formula 2. When two atoms present, usually one with only one atom present 3. Hydrogen is exception 4. Aim for symmetrical structure 5. Start with outer lone pair electrons and work in Lewis Structure: 1. Calculate total valence electrons E.g. for CS2: (4x1) carbon + (2x6) sulfur= 16 valence electrons 2. Draw
