Notes, summaries, assignments, exams, and exercises for Chemistry for University

Element: refers to a class of atoms, all s them with the same number of protons in its nucleus. Although traditionally chemical element can be defined as that substance that can not be decomposed by chemical reaction, into simpler COMPOUND: a substance formed by the joining of two or more elements of the periodic table, in a fixed ratio . MIXTURE: A mixture is a material system consisting of two or more pure substances, without chemical reaction chemically. AGGREGATION STATES OF MATTER: In chemistry shows that, for any substance or material element, changing the conditions of temperature or pressure, can be obtained from different states or phases, known as states of aggregation of matter in relation to the binding forces of the particles (...

Ketogenesis

Ketogenesis is the biochemical process by which ketone bodies are produced as a result of fatty acid breakdown.

Phase 1: Acetoacetyl-CoA Formation

Acetyl-CoA + Acetyl-CoA → Acetoacetyl-CoA

Phase 2: HMG-CoA Synthesis

Acetoacetyl-CoA + Acetyl-CoA + H₂O → Hydroxymethylglutaryl-CoA (HMG-CoA)

Phase 3: Ketone Body Production

Hydroxymethylglutaryl-CoA (HMG-CoA) → Acetoacetate → Acetone AND β-Hydroxybutyrate

Deamination of Amino Acids

Deamination is the removal of an amino group from an amino acid.

Non-Oxidative Deamination

Serine Complex Unstable → Imino Acid → Pyruvic Acid + Ammonia (NH₃)

Oxidative Deamination

Amino Acid (AA) → Imino Acid → Keto Acid + Ammonia (NH₃)

Glycolysis

Glycolysis is the metabolic pathway that converts...

Chlorides

Chlorine, as an element, has a huge tendency to form the chloride ion (Cl^-, a chlorine atom with a negative charge). This ion, in turn, will tend to form salts with other positively charged elements or cations (Na⁺ sodium, K⁺ potassium, Mg²⁺ magnesium, etc.). The chloride ion is one of the main inorganic anions in natural water and wastewater. The chloride content of water is variable and is mainly due to the nature of the terrain traversed. Typically, the chloride ion content of natural waters is less than 50 mg/L. In drinking water, the salt produced by the Cl^- is variable and depends on the water chemistry.

Chlorite and Chlorate

These are salts derived from chloric acid and chlorous acid. These compounds tend to form chlorine gas,...

Ozone (O3 ) is a made with three oxygen atoms; it is very unstable and has a short lifetime. At room Temperature and pressure has acrid odour and no colour, although at high concentration levels can turn Into blue. At high concentrations can be toxic and can cause death. It s not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. VOC + NOx + sunlight tropospheric O3Particulate Matter (PM) "Particulate matter," also known as particle pollution or PM, is a complex mixture of extremely small Particles and liquid droplets. Particle pollution is made up of a number of components, including acids (such as nitrates and sulfates), organic...

Atomic Structure

Elements are a type of atom. Atoms are made up of protons, neutrons, and electrons. The nucleus is the center of an atom.

• Proton: +1 charge
• Electron: -1 charge
• Neutron: 0 charge (neutral)

Rutherford (1911) conducted the gold foil experiment.

Different elements have different numbers of protons in the nucleus.

• Atomic number (Z): Number of protons
• Mass number (A): Number of protons + Number of neutrons

Z

Chemical Symbol

A

Neutron number = Mass number - Atomic number

The number of neutrons can change (protons stay the same) in a given atom, making them isotopes.

Atomic mass is the total mass of elements and all its isotopes. U represents atomic mass units.

A radioactive isotope consists of nuclides whose nuclei undergo spontaneous decay.

Three

Solubility Fundamentals

Definition of Solubility

Solubility: The maximum concentration of a solute in a saturated solution at a given temperature in a given solvent.

Factors Affecting Salt Solubility

• Temperature (Temp): Generally, higher temperatures increase solubility.
• Entropy: Highly soluble substances often exhibit high entropy (disorder); the reverse is true for less soluble substances.
• Ion Size: A greater size difference between ions typically leads to higher solubility.
• Charge Density: This is the ratio between the ion's charge and its size. Lower charge density results in higher solubility because the solvent can more easily overcome the electrostatic attraction between the ions of the compound.

Equilibrium Factors Affecting Solubility

• Common

Copper: Properties and Applications

Copper is reddish in color with a metallic luster. It is characterized as one of the best conductors of electricity and heat. Thanks to its high electrical conductivity, ductility, and malleability, it has become the most widely used material for manufacturing electrical cables and various electrical and electronic components. Copper is a highly durable metal because it can be recycled almost indefinitely without losing its metallic properties.

Refining Copper

Copper refining is the process of removing impurities that make the metal brittle (both cold and hot). This process facilitates rolling and drawing into wire and thread, ensuring optimal application for electrical conductors, as impurities significantly

Stoichiometry: Quantitative Chemical Relationships

In chemistry, stoichiometry (from the Greek "στοιχεῖον" = stoicheion (element) and "μέτρον" = metron (measure)) is the calculation of the quantitative relationships between reactants and products during a chemical reaction. These relationships can be deduced from atomic theory, although historically they were formulated without direct reference to the composition of matter, based on various laws and principles.

Molarity (Molar Concentration)

Molarity (M), or molar concentration, is the number of moles of solute per liter of solution. For example, if 0.5 mole of solute is dissolved in 1000 mL of solution, the concentration of that solute is 0.5 M (0.5 molar).

Molality

Molality (m)

Fire Extinguishment Methods

Cooling: Reducing Fuel Temperature

This method reduces the temperature of the fuel, causing the fire to extinguish as no vapors can escape to sustain combustion. Water is the most effective agent for this purpose.

Suffocation: Cutting Off Oxygen

This method prevents vapors released from the fuel at a certain temperature from contacting oxygen in the air, thereby cutting off the oxygen supply to the fire.

Inhibition: Chemical Fire Suppression

This method prevents the transmission of heat from one fuel particle to another by interposing catalysts. It involves applying chemicals that alter the chemistry of the combustion reaction. Examples include PQS (Dry Chemical) and Halon fire extinguishers.

Dilution: Fuel Removal

This...

Casting Process for Oral Appliances

Casting is the process whereby the appliance is formed from an alloy in the space left by the wax pattern to manufacture different types of oral prosthetic devices.

Key Stages in the Dental Casting Process

1. Achievement of the wax pattern.
2. Investing the wax pattern.
3. Wax removal (burnout).
4. Melting the alloy and casting.
5. Finishing and polishing.

Refractory Foil Rings

These rings are used during the investment process.

Types of Refractory Foil Rings

• Asbestos (now largely replaced)
• Cellulose
• Ceramics

Functions of Refractory Foil Rings

• Insulation: Avoids abrupt warming of the investment material and facilitates the removal of the ring after casting.
• Expansionist: Contributes to expansion (setting, thermal, and hygroscopic).

Dental