Given the standard reduction potential for Au31 in Table 18.1 and Au1(aq) 1 e2 Au(s) E 5 1.69 V answer the following questions. (a) Why does gold not tarnish in air? (b) Will the following disproportionationoccur spontaneously? 3Au1(aq) Au31(aq) 1 2Au(s) (c) Predict the reaction between gold and fluorine gas
1.) Water & theAtmosphere (4-19-17) TheAtmosphere • Thin envelope of gases (air) that surround the Earth. Contains material that allows us to live. • It is there because we have a magnetic field. • Composed of… Nitrogen 80% • • Oxygen 20% • Other:Argon, carbon dioxide, methane, nitrous oxide • Water vapor (humidity) Structure of theAtmosphere • It is not visible. We know it exists because we deal with temperature. • 4 Layers: • Troposphere (0-14 km): Most Dense, weather systems take place here. • Stratosphere (15-50 km): Ozone layer. Mesosphere (58-85 km): Temperature is going down as you move up towards the surface • of the Earth. • Thermosphere (90-500 km): Upper atmosphere. 3 States of Water • Solid, liquid, gas • Gas —> liquid —> Ice • Gas is less ordered and ice is more ordered. • What Determines the State • Temperature determines the state of the water. Water and Weather • Water has amazing surface tension. Water is attracted to water. • The thermal properties allow the transfer of heat from the sun into the storm system. • Heat energy released or absorbed. • Water can absorb or release substantial quantities of heat without any significant change in temperature. • Specific heat (heat capacity) - very high. Latent heat (energy released or absorbed during change of state). • • When it goes from the water phase to the vapor phase, evaporation heat is absorbed. When it goes form vapor to water, condensation heat is released. •
