Fundamentals of Chemical Bonding and Compounds
Chemical Bonds
Covalent Bond Types
A covalent bond takes place between atoms that share pairs of electrons. The type depends on the electronegativity difference (ΔEN) between the atoms:
- Nonpolar covalent: Occurs between atoms sharing electron pairs with an electronegativity difference of zero (ΔEN = 0).
- Polar covalent: Occurs between atoms sharing electron pairs with an electronegativity difference greater than 0 but less than 1.7 (0 < ΔEN < 1.7).
- Coordinate covalent bond: In this bond, one
Fuel Properties, Coal Analysis, and Corrosion Science
Fuel Definition and Types
A fuel is defined as any substance that can provide heat and produce energy when it is burned. The energy released is generally in the form of chemical energy or heat energy.
Examples of fuel:
- Methanol
- Gasoline
- Diesel
- Natural gas
Types of fuel:
- Solid fuel
- Liquid fuel
- Biofuel
- Fossil fuel
Characteristics of a Good Fuel
A good fuel has the following characteristics:
- Availability: It should be readily available.
- Cost: It should be inexpensive.
- Combustion: It should burn easily in air at a
Core Chemistry Concepts and Calculations
Fundamental Chemistry Definitions
- Which statement best defines chemistry?
- The science that studies the connections between the properties of matter and the particles that compose that matter.
- Where can we find chemicals?
- Everywhere.
- Which statement most resembles a scientific theory?
- A gas is composed of small particles in constant motion.
- According to scientific methods, what is a Law?
- A short statement that summarizes a large number of observations.
Measurements and Calculations
Significant Figures
How many
Read MoreFundamental Chemistry: Elements, Atoms, Laws, and Bonding
Fundamental Chemistry Concepts
Basic Definitions
- Element: A pure substance that cannot be broken down by either physical or chemical methods.
- Compound: A pure substance that can be decomposed into its constituent elements by chemical methods.
Fundamental Chemical Laws
- Law of Conservation of Mass (Lavoisier): The total mass of reactants equals the total mass of products in a chemical reaction.
- Law of Definite Proportions (Proust): When two or more elements combine to form a compound, they always do so
Vitamin C Content in Citrus Juices: A Comparative Analysis
Discussion
The results demonstrate that orange juice has a higher vitamin C content per unit volume compared to lemon and lime juices. Orange juice exhibited the highest ascorbic acid concentration at 0.319 M, while lemon juice had a similar concentration at 0.319 M. Lime juice had the lowest concentration at 0.277 M. These findings support the hypothesis that oranges possess the highest vitamin C content and align with previous studies confirming this observation.
While concordant titers enhanced
Read MoreKey Concepts in Analytical Chemistry
Gravimetric Analysis
Gravimetric analysis is a technique in which the only measurement performed is mass.
Analyte
The analyte is the species whose composition is required to be determined.
Stages of Gravimetry
Precipitation
If the solid sample is weighed, it is dissolved, and then the precipitating agent is added.
Digestion
The precipitate remains in contact with the mother liquor in order to improve the quality of the crystals.
Filtering
Filtering prevents the loss of the solid. It should be done with cold
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