Natural Resources, Manufacturing & Environmental Management
Item 11: Natural Resources and Manufacturing
Natural Resources
Water, air, minerals, rocks, oil, natural gas, timber, and agricultural products are examples of natural resources.
Manufacturing
Key processes involve acids and bases under specific conditions (durable, accessible, abundant).
Classification of Resources
Resources are classified based on their durability:
- Inexhaustible: Air (separation of components by distillation, nitrate combination, electrical discharges, ozone), Water (desalination, potable
Alkali, Alkaline Earth, Earthy & Carbonoide Elements
Alkali Metals
The alkali metals, Lithium, Sodium, Potassium, Rubidium, Cesium, and Francium, are in Group 1 of the periodic table. They are named for the alkalinity of their compounds. Due to their chemical activity, they are not found in a free state and comprise almost 5% of the Earth’s crust (especially Sodium and Potassium).
Properties
- Electronic configuration: ns1
- Low first ionization energy
- Low electronegativity, decreasing down the group
- Common oxidation state: +1
- Form ionic compounds
- Low melting
Chemical Reactions, Equilibria, and Industrial Processes
Hess’s Law
If a reaction can be performed in several steps, whether real or theoretical, the total enthalpy change is equal to the sum of the enthalpy changes of these intermediate reactions.
Standard Enthalpy of Reaction
From standard enthalpies of formation.
From bond enthalpies.
Standard Entropy of Reaction
Free Energy
Spontaneous
Theories of Chemical Reactions
Collision Theory
For a chemical reaction to occur, reactants (atoms, molecules, or ions) must collide. Effective collisions require:
- Sufficient
Atomic Structure and Chemical Reactions
Atomic Structure
Dalton’s Atomic Theory and Its Demise
Dalton’s atomic theory proposed that matter consists of indivisible particles called atoms. However, the discovery of the electron, a subatomic particle, challenged this theory.
Cathode Rays and the Electron
Cathode rays exhibit specific properties:
- They travel in a straight line from the cathode to the anode, producing fluorescence upon hitting the tube walls.
- They behave like a negatively charged electric current, deflecting towards the positive
Polymer Chemistry, Ceramics, and Composite Materials
Polymer Chemistry
For obtaining a polymer in polymer chemistry, hundreds of thousands of molecules (monomers) are chemically bound. Homopolymers are obtained if the polymer chain is formed by the union of identical monomers. If the polymer chain is formed by the union of different monomers, copolymers are obtained.
Polycondensation: The chain growth occurs by chemical reaction between two functional groups, in most cases with the loss of a small molecule, such as water or hydrochloric acid.
Polyaddition:
Read MoreImprovised Detonators and Explosives Construction
Detonators of delay, also known as time detonators, are useful in various applications. Here are some examples:
Mecha Time
It is relatively simple to create time detonators using fuses for ignition. One common method involves cigarettes, which burn for approximately eight minutes. By determining the burn time of a cigarette, you can plan its use as a delay fuse.
A similar method uses a rolled paper tube filled with coal dust and a leaf. Powdered coal mixed with finely ground materials can also serve
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