Primary Air Pollutants: Sources, Impacts, and Control
Primary Air Pollutants
Sulfur Dioxide (SO2)
Properties: Colorless gas, reactive, soluble, and has a pungent odor at higher concentrations.
Sources:
- Natural: Organic matter decomposition, volcanic eruptions.
- Anthropogenic: Industrial processes (fossil fuel combustion, refining, chemical manufacturing).
Fate: Oxidizes to form SO3, leading to acid rain through dry and wet deposition.
Nitrogen Oxides (NOx)
Properties: NO (nitric oxide) is colorless, odorless, and non-flammable. NO2 (nitrogen dioxide) is a reddish-
Read MoreRedox Reactions, Voltaic Cells, and Electrolysis
Redox Reactions
Oxidation and Reduction
Oxidation: The process of electron loss by a reductant. The reductant is the substance that contains the element whose oxidation number increases.
Reduction: The process of electron gain by an oxidant. The oxidant is the substance that contains the element whose oxidation number decreases.
- Oxidation: Process where an element’s oxidation number increases (loses electrons).
- Reduction: Process where an element’s oxidation number decreases (gains electrons).
Redox Reactions:
Read MoreChemical Bonding: An In-Depth Exploration of Ionic, Covalent, and Metallic Bonds
The Periodic Table and Element Classification
The arrangement of elements in the periodic table is based on their atomic number, a concept discovered by Henry Moseley through his study of X-ray spectra. This organization reflects the electronic configuration of each element, with periods representing the filling of electron energy levels. The first period holds two elements, the second and third contain eight each. While subsequent periods also fill ‘d’ and ‘f’ sublevels, these are energetically
Read MoreChemical Equilibrium and Le Chatelier’s Principle
Chemical Equilibrium
The chemical equilibrium is a reversible process where the rates of the forward and reverse reactions are equal, resulting in constant reactant and product concentrations over time. When all species are in the same phase, the equilibrium is homogeneous.
Homogeneous Equilibria: Law of Mass Action
In a homogeneous equilibrium, all chemical species are in the same phase. A general homogeneous equilibrium is represented as: aA + bB ⇌ cC + dD. At a given temperature, a constant ratio
Read MoreFundamental Chemistry Laws, Atomic Models, and Periodic Properties
Fundamental Chemical Laws
Law of Conservation of Mass
In any chemical reaction that takes place in a closed system, mass is conserved: The mass of starting substances (reactants) is the same as that of the final products.
Law of Definite Proportions
When two or more elements combine to yield a compound, they do so in a fixed proportion.
Law of Multiple Proportions
When two or more elements combine to form different compounds, they do so in a ratio of small whole numbers.
Dalton’s Atomic Theory
- Chemical
Electron Configuration and Chemical Periodicity
Electron Configuration
Pauli Exclusion Principle
Two electrons in the same atom cannot have identical quantum numbers. Since electrons in the same orbital are identical, an orbital cannot contain more than two electrons.
The maximum number of electrons per energy level is 2n2
Electronic Configuration of the Elements
Spectral Notation
Spectral notation schematically represents the distribution of electrons in an atom based on Bohr’s atomic model. Electrons tend to occupy the lowest energy orbitals.
The
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