Atmospheric Chemistry: Composition, Reactions, and Environmental Impact
Steady state balance between protons and electrons. Rocks = eruptive volatile atmosphere + sea water sediments. Determined by atmospheric composition, seawater pH, redox potential of 0.75. Non-photosynthetic microorganisms act as catalysts. pE = E / 2.303RT / F in 25 ºC.
pE0 = E0 / 2.303RT / F in 25 ºC. F = Faraday constant. pE = -log (ae-). It accounts for the effects of different electrode potential activities. Fe3+ + e– ⇌ Fe2+, E0 = +0.77 volts, pE0 = 13.2. The Nernst equation is: E = E0 +
Read MoreChemical Equilibrium, Reaction Rates, and Solutions
Mass Action Law
The mass action law states that the value of the equilibrium constant Kc is constant for a particular reaction at a constant temperature, provided that equilibrium concentrations are used. The mathematical expression representing the equilibrium constant at a certain temperature is:
aA + bB ⇌ cC + dD
Kc = ([C]c[D]d) / ([A]a[B]b)
This shows that the equilibrium constant is the ratio of the product concentrations to the reactant concentrations, each raised to the power of their stoichiometric
Read MoreIntermolecular Forces, Thermodynamics, and Chemical Kinetics
Intermolecular Forces
F. Orientation/Permanent Dipole-Dipole
Dipoles are oriented; the positive pole of one molecule attracts the negative pole of the nearest molecule. The force (F) of attraction increases with polarity. This is present in liquids and gases. Examples of weak attractions include HCl, NH3, H2O, and ethanol.
F. Dispersion/London Forces
These forces occur between nonpolar molecules due to instantaneous dipoles caused by electron vibration. The force value increases with molecular mass
Read MoreMetal Production: Mining, Metallurgy, Alloys, and Iron-Carbon Processes
Metal Production Processes
Mining and Metallurgy
Mining involves extracting ore deposits and separating the metal-rich parts from other materials. Metallurgy is the set of processes used to obtain metals from their ores, separating them from other elements. Metallic industries create useful items from metals.
Historical Significance and Recycling
Iron and its derivatives (steel and cast iron) have significant historical importance. Metallurgy also includes obtaining steel from siderite (iron ore). Metals
Read MoreUnderstanding Metal Corrosion: Processes and Prevention
Understanding Metal Corrosion
Metal corrosion is the transformation of a metal or metal alloy through chemical or electrochemical interactions, resulting in corrosion products and energy release.
Metallic corrosion (electrochemical mechanism) typically occurs when metal is exposed to water molecules, oxygen gas, or hydrogen ions in a conductive medium.
Protection Against Metal Corrosion
Protection methods must consider technical and economic aspects. Exposure is crucial. Corrosion inhibitors or controlling
Read MoreA History of Technological Advancements
Etymology of Technology
The word “technology” originates from the Greek technologia, meaning systematic treatment of an art, derived from techne (art, skill) + -o- + -logia (logy) in 1859.
The Scientific Revolution (17th Century)
Key Events:
- 1649: Charles I beheaded (English Revolution)
- 1688: Changes in England
- 1700: War of Spanish Succession (concluded in 1713)
- 1756: Seven Years’ War
- 1760: James Cook’s voyages
- 1776: American Revolution (concluded in 1783)
- 1815: Napoleonic Wars and Congress of Vienna
- 1829: