CHEM 120 Lecture Notes - Lecture 30: Alpha Decay, Oxygen-18, Positron

• School: McGill University
• Department: Chemistry
• Course: CHEM 120
• Professor: Laura Pavelka

Document Summary

Secondary batteries: rechargeable, self-contained series of voltaic cells, electrical current supplied to reverse the cell reaction: lead-acid battery (6 cells in series, car batteries used to start engines) Anode = pb grid with pb(s), cathode = pb grid with pbo2(s), electrolyte = Pb(s) + pbo2(s) + 2h2so4(aq) 2pbso4(s) + 2h2o() (ecell = 2. 1v: nickel-metal hydride (ni-mh) battery: lightweight, discharges during storage. Anode = mh(s); cathode = nio(oh)(s); elecgtrolyte = koh(aq) Mh(s) + nio(oh)(s) m(s) + ni(oh)2(s) (ecell = 1. 4v: lithium ion battery: laptops, cellphones, high cost, flammable. Anode = li+ + graphite; cathode = li-m oxide, electrolyte = lipf6 in organic solvent. Lixc6 + li1-xmn2o4(s) limn2o4(s) + c6(s) (ecell = 3. 7v) 1: part of atom involved, energy/mass changes not significant (conservation. Temperature, concentration, pressure, which atom & its position, catalysts, compounds, etc: dependencies of reaction rates. Significant (conservation of mass energy, but have conversion of mass to energy at a significant level) Only thing that matters is # of nuclei.