Notes, summaries, assignments, exams, and problems for Chemistry

Links and interaction:
Link: q down at junctions to form dif compounds and the goal is stability.

E. Ionian (+ strong) (M + NM)
The - in Cedeno E. And the + to reach. Both can be combined.
E. Covalent (+ weak) (NM + NM) (EX: cl2, CO2, H2, H20)
I share their valence.
E. Metallic. + ions form networks, move easily, the latest E levels (valence).
Intermolecular forces: it depends on physical condition and character of st ud them. The + weak Van der Waals.
Ranking 2: dipoles (between E. Covalent polar mol), polarization transient (london: between nonpolar covalent mol), PH (an H is linked to another major in such as O, N or F) <P Boiling affects ..
Mixing:
Solubility of a solute: q max amount is dissolved in a fixed amount of a solvent... Continue reading "Chemical Principles: Bonds, Solutions, and Gas Laws" »

Understanding Carbohydrates

Carbohydrates are biomolecules primarily composed of carbon, hydrogen, and oxygen. Their atoms are linked to alcohol groups (hydroxyl groups, -OH) and hydrogen atoms (-H). All carbohydrates contain a carbonyl group (C=O), which can be either an aldehyde group (-CHO) or a ketone group (-CO). Therefore, they can be defined as polyhydroxyaldehydes or polyhydroxyketones.

Classification of Carbohydrates

Carbohydrates are classified into several groups:

• Monosaccharides: Simple sugars made of single units.
• Oligosaccharides: Contain between 2 and 10 monosaccharide units.
• Polysaccharides: Formed by multiple repeating units of monosaccharides, further divided into:
  • Homopolysaccharides: Formed by the repetition of a single monomer.

Analysis and Instrumentation

Physical Properties:

• Hardness
• Color
• Shape
• Smell
• Ductility
• Density
• Flavor
• Malleability
• Volatility
• Viscosity
• Conductivity
• Weight
• Volume
• Brightness
• Porosity
• Toughness
• Boiling Point (Punto de ebullición)
• Melting Point (Punto de fusión)

Chemical Properties:

Chemical reactions.

Composition:

CaCO3 100%

Determining the Composition of Liquids, Gases, and Solutions: Instrumental Applications

Objectives:

• To know the fundamentals and applications of instrumental techniques in environmental engineering.
• Understand the general problem of analysis.
• Purchase criteria for a particular control method.
• Analysis, sampling, preservation, and preparation of samples.
• Distinguish the key parts and functions of each instrumental technique.
• Interpret information obtained

Chemical Bonds and Properties

Ionic Bonds

Ionic bonds are characteristic of compounds formed between a metal and a non-metal. Metals form positive ions (cations), and non-metals form ion-accepting negative ions (anions).

Properties of Ionic Compounds

• Soluble in water
• Hard and fragile
• Have an ionic crystal structure

Covalent Bonds

Covalent bonds are seen in particles formed by atoms of non-metals, as is the case of diatomic gas molecules. Atoms share one or more pairs of electrons to complete their outer octet.

Properties of Covalent Compounds

• Do not conduct electric current
• Molecules of simple gases have covalent bonds
• Have atomic or molecular crystalline structure

Types of Covalent Bonds

• Polar Covalent
• Non-Polar Covalent
• Coordinate Covalent: Two electrons

Lipids: Classification and Key Characteristics

LIPIDS: Lipids are classified into three major groups: fatty acids (saturated and unsaturated), saponifiable lipids (simple and complex, including acylglycerides and waxes) and unsaponifiable lipids (terpenes, steroids and prostaglandins).

Fatty Acids: Structure and Properties

Fatty acid: a hydrocarbon chain typically from 12 to 22 carbon atoms with a terminal COOH (carboxyl) group. They are divided into:

• Saturated fatty acids — chains with no double bonds; they adopt an extended, zigzag conformation and have stronger van der Waals interactions between hydrocarbon chains, producing higher melting points.
• Unsaturated fatty acids — chains that contain one or more double bonds; double bonds create

Atomic Structure and Chemistry Fundamentals

Organic chemistry is the science of matter. All matter occupies space. Plasma is when atoms are in a high-temperature environment.

• Elements: A single type of atom that cannot be transformed into simpler substances.
• Compounds: Substances formed by different types of atoms combined in a constant ratio.
• Homogeneous: Has a single phase, and components are indistinguishable (H₂O + C₆H₁₂O₆). Can be separated by evaporation or distillation.
• Heterogeneous: Components can be distinguished from each other.
• Phase: A portion of matter with definite limits. Can be separated by filtering or decanting.

d = mass / volume

Prefixes: milli (m) - 10^-3 / micro (μ) - 10^-6 / nano (n) - 10^-9

1 kg = 1000 g and 1 dozen = 12 units

Temperature... Continue reading "Atomic Structure, Compounds, and Chemical Formulas" »

Nuclear Physics Fundamentals

The atomic nucleus is formed by nucleons (protons and neutrons). The atomic number (Z) defines the mass.

Nuclide Classifications

• Isotopes: Nuclides with the same number of protons but a distinct number of neutrons.
• Isobars: Nuclides with the same mass number (A) but a distinct number of protons and neutrons.
• Isotones: Nuclides with the same number of neutrons but a different number of protons.

Fundamental Forces of Nature

• Gravitational Force: Exerted between two particles with mass. It is always attractive and responsible for the existence of planets and stars. It is a weak, long-range interaction.
• Electromagnetic Force: Exerted between two electrically charged particles. It can be attractive or repulsive and is responsible

Matter: Core Properties, States, and Mixtures

Matter is anything that has mass and occupies volume. It is characterized by two types of properties:

Key Properties of Matter

• General properties: These are mass and volume.
• Specific properties: These are different in each material, so they serve to differentiate materials from each other and assign them different uses.

The Three States of Matter

Matter can occur in three states:

• Gas: A gas has no definite shape and spreads to fill its container. It can be compressed and expands greatly with temperature.
• Liquid: A liquid does not hold its own shape (it takes the shape of its container) but has a definite volume. It is not easily compressed and expands slightly with increasing temperature, although much

Acid–Base Theories

Arrhenius (1883)

Acid: A substance that yields H⁺ in aqueous solution. Base: A substance that in aqueous solution gives OH^-.

Limitations: substances with basic properties that do not contain hydroxyl ions (e.g., NH₃); limited to aqueous solutions. Free, isolated protons do not exist in water.

Brønsted–Lowry (1923)

Acid: A species that tends to donate an H⁺. Base: A species that tends to accept an H⁺.

Lewis (1923)

Acid: A species that can accept an electron pair. Base: A species that can donate an electron pair.

Buffer Solutions

1. Buffer (dissolution buffer)

Definition: Buffer solutions are solutions that maintain a nearly constant pH when small amounts of acid or base are added, or when diluted.

Composition: Significant amounts... Continue reading "Acid–Base Theories, Buffers, Indicators, Titrations & pKa List" »

Binary Compounds

Binary Oxygen Compounds (Oxides)

Systematic Nomenclature

• Prefixes (mono-, di-, tri-, tetra-...) + oxide (element symbol).
• e.g., N₂O₅: Dinitrogen pentoxide.

Stock Nomenclature

• Oxide of (element) + (valence of element in Roman numerals).
• e.g., N₂O₅: Nitrogen(V) oxide.

Binary Hydrogen Compounds (Hydrides)

Metal Hydrides (Hydrogen + Metal)

Systematic Nomenclature

• Prefixes (mono-, di-, tri-, tetra-...) + hydride of (metal).
• e.g., CrH₃: Chromium trihydride.

Stock Nomenclature

• Hydride of (metal) + (valence of metal in Roman numerals).
• e.g., CrH₃: Chromium(III) hydride.

Volatile Hydrides (Hydrogen + Semimetal)

Systematic Nomenclature

• Prefixes (mono-, di-, tri-, tetra-...) + hydride of (semimetal).
• e.g., PH₃: Phosphorus trihydride.

Common Names

• Ammonia