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

Fundamentals of Polymers

Polymer: Giant organic molecules with molecular weights ranging from 10,000 to 1,000,000 g/mol.

Monomer Unit: The structural entity that is repeated along the polymer molecule.

Monomer + Catalyst → Reactive Monomer Unit

Classification of Polymers

• Mechanism of Polymerization: Addition and condensation.
• Molecular Structure: Linear, branched, and cross-linked.
• Thermal Behavior:
  • Thermoplastics: Plastic polymers that soften when heated and harden upon cooling. This process is reversible; they are typically soft and ductile (e.g., Polyamide via spinning).
  • Thermosets: Plastic polymers that harden irreversibly when heated; they are hard, tough, and fragile (e.g., Melamine via compression).
• Nature of Monomer Units: Homopolymers and

Egg Protein Composition and Quality

Eggs contain proteins that are of the highest quality. It is necessary to distinguish between the white and the yolk, both in terms of quality and quantity.

The Egg White

The egg white, or Clara, consists of clear proteins and almost corresponds to a protein solution. Most of these proteins are biologically active as enzymes, inhibitors, or antibodies. Their functional foaming capacity may diminish or disappear due to heating, freezing, dehydration, mechanical strength, and also by adding some chemicals such as NaCl.

Primary Egg White Proteins

• Ovalbumin: It is the most abundant protein (54%). It has a molecular weight of 45,000. It easily denatures and has many SH groups.
• Conalbumin: Represents 13% of the total.

Polyether Dental Impression Materials

Elastic impression materials are based on a polyether polymer with a reactive aziridine ring. These materials stiffen in the presence of a catalyst through a cationic polymerization process.

Synonyms

• Polyether
• Polyether polymer
• Polyethers

Chemical Composition of Self-Curing Materials

• Base: Polyether groups (aziridines), silica (filler), and phthalate glycol (plasticizer).
• Catalyst: Alkyl sulfonate (reactor that generates the ring opening), silica (filler), phthalate glycol (plasticizer), and solvent (octyl phthalate).

Curing Chemical Composition

• Base: Polyether resin, urethane dimethacrylate, and silicon dioxide (filler).
• Initiator: Light-activated photoinitiator.

Chemical Reaction: Polyether (base) + Alkyl sulfonate...

Anions: Definition and Characteristics

An anion is an ion (an atom or molecule) that possesses a negative electrical charge, meaning it has an excess of electrons. Anions are typically described with a negative oxidation state. They are broadly classified into two main types: monatomic and polyatomic.

Monatomic Anions

Monatomic anions are typically formed when nonmetals gain electrons to complete their valence shell.

Traditional Nomenclature (Monatomic)

These are named using the word ion followed by the name of the nonmetal, ending in the suffix -ide. (Note: Amide and Cyanide are often included here for simplicity, though technically polyatomic.)

• Cl^-: Chloride ion
• H^-: Hydride ion
• S^2-: Sulfide ion
• NH₂^-: Amide ion
• CN^-: Cyanide ion

Systematic Nomenclature

Vowel Phonemes

Vowel phonemes are speech sounds produced with an open vocal tract, allowing air to flow freely. They are classified by tongue position (front, central, back), tongue height (high, mid, low), and lip rounding.

• /i/: Front, high, unrounded (e.g., as in "feet")
• /e/: Front, mid, unrounded (e.g., as in "bed")
• /a/: Central, low, unrounded (e.g., as in "father")
• /o/: Back, mid, rounded (e.g., as in "boat")
• /u/: Back, high, rounded (e.g., as in "boot")

Consonant Phoneme Allographs

A single phoneme (distinct sound unit) can have different spellings (graphemes or allographs) depending on the context or language:

• /b/: b, v, w (e.g., ball, van, wear – depending on language and pronunciation)
• /s/: z (e.g., zoo), c (before e, i; e.g., city)
• /k/: c

Bonding

Formal Charge: # Valence Electrons - (Nonbonding Electrons + 1/2 Bonding Electrons)

Gases

STP = Standard Temperature and Pressure (273 K or 0°C and 1 atm)

Ideal Gas Law

R = 0.0821 atm x L / (mol x K)

• Pressure (P): Always in atm
  • 760 mmHg = 1 atm
  • 760 Torr = 1 atm
  • 101,326 Pascal = 1 atm
• Temperature (T): Always in Kelvin
• # of Moles (n)
• Volume (V): Always in Liters

Boyle's Law

Occurs when T and n are constant.

Charles's Law

Occurs when P and n are constant.

Avogadro's Law

Occurs when P and T are constant.

Gay-Lussac's Law

Occurs when V and n are constant.

Combined Gas Law

n is constant.

Test

1. a) Valence Electrons for Na⁺ = 0
2. b) Which of the following does not have an octet around the central atom: BCl₃
3. d) A triple bond has a bond order of: 3
4. c) Least electronegative

1. Phases of Pure Substances

• Solid: Molecules are closely packed and vibrate in place due to strong intermolecular forces.
• Liquid: Molecules are closer together but remain free to move with weaker intermolecular forces.
• Vapor: Molecules are far apart and possess very high kinetic energy.

2. Phase Change Processes

• Compressed Liquid: A liquid that is not about to vaporize (e.g., water at 20°C and 1 atm).
• Saturated Liquid: A liquid that is about to vaporize (e.g., water at 100°C and 1 atm).
• Saturated Vapor: Vapor that is about to condense (e.g., steam at 100°C and 1 atm).
• Superheated Vapor: Vapor that is far from condensing (e.g., steam at 150°C and 1 atm).

3. Latent Heat

• Latent Heat of Fusion: The energy required to change 1 kg of solid into liquid.

An Arrhenius acid is a substance that dissociates in water to form hydrogen ions or protons. In other words, it increases the number of H⁺ ions in the water. In contrast, an Arrhenius base dissociates in water to form hydroxide ions, OH^-.

A Bronsted-Lowry acid is a solution that donates protons and is known as a proton donor. The Bronsted-Lowry base, on the other hand, is a solution that accepts protons and is known as a proton acceptor. Going back to a Bronsted-Lowry acid, in general, it must contain a hydrogen ion that it can give up.

Mineralogy and Crystallography

1. Define Polymorphism

Polymorphism refers to the phenomenon where the same chemical substance can exhibit different physical and even chemical properties due to variations in formation conditions, such as pressure and temperature. These variations lead to different arrangements of atoms within the crystal structure.

2. Define Isomorphism

Isomorphism occurs when two or more chemical compounds adopt the same crystalline structure.

3. Define Pseudomorphs

Pseudomorphs are minerals where the internal structure does not correspond to the external crystal form, resulting in a "false form."

4. Define Solid Solution and Mixing

• Solid solution: A homogeneous solid with a variable composition.
• Mixing: A type of solid solution where