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

Fundamentals of Biochemistry

Energy is essential for all biological processes. All atoms contain energy, and they are joined together by chemical bonds, which are crucial for life. We obtain our energy from food, converting it into chemical energy that can be stored and utilized, as opposed to other forms of energy like light and heat that cannot be retained.

Thermodynamics Principles

• First Law: Energy is neither created nor destroyed; it is only transformed from one form to another.
• Second Law: In every energy transmission, some energy is lost, typically as heat, leading to an increase in entropy.

Atomic Structure

The basic units of matter are atoms, composed of three fundamental subatomic particles: neutrons (neutral charge), protons (positive...

ionophore: a pesomolecular compounds ranging from 500-2000, which have a hydrophobic outer surface which is soluble in lipids, and a hydrophilic interior to which the ion binds. There is little evidence that ionophores are physiological constituents of energy-transducing membranes. Through two mechanisms can function as mobile carriers and as trainers of channels or conduits. The mobile carriers can diffuse through the membrane lipid matrix and catalyze the transport of a few thousand ions per second across the membrane. They can show a high selectivity towards the different ions, heavy work through synthetic membranes, but are affected by the state of membrane fluidity. Example, valinomycin is highly selective for potassium cation. By contrast,...

Physical Properties of Alcohols

• State: Lower alcohols are liquids; higher alcohols are solids.
• Density: Less dense than water.
• Boiling Points: Higher than corresponding alkanes.
• Solubility: Decreases as the number of carbon atoms increases.

Common Alcohols

• Methanol: CH₃OH
• Ethanol: CH₃CH₂OH

Ethanol Production

• Natural: C₆H₁₂O₆ → 2CH₃CH₂OH + 2CO₂
• Artificial: CH₂=CH₂ + H₂O → CH₃CH₂OH

Chemical Properties of Alcohols

Alcohols undergo oxidation reactions that distinguish primary, secondary, and tertiary structures:

• Primary Alcohols: Oxidize to form aldehydes (e.g., CH₃CH₂OH + ½O₂ → CH₃CHO + H₂O).
• Secondary Alcohols: Oxidize to form ketones (e.g., CH₃-CHOH-CH₃ + O₂ → CH₃-CO-CH₃ + H₂O).
• Tertiary Alcohols:

Stereoisomerism and Carbohydrate Structure

Asymmetric carbons occur when a radical is attached to four different groups, leading to stereoisomerism. Isomers are compounds with the same molecular formula but different chemical properties.

Monosaccharides and Cyclic Structures

Haworth projections represent monosaccharides where each carbon radical is positioned at the top or bottom of the plane. The ring is formed by a covalent bond joining an alcohol group with an aldehyde or ketone.

• Anomeric Carbon: A new asymmetric carbon that appears in monosaccharides when forming cyclic structures from aldehyde or ketone groups.
• Mutarotation: The change in the rotation values of plane-polarized light during the transition from one anomer to another.
• Fehling's

Electrical Conductivity in Water

Electrical Conductivity: Pure water is a poor conductor of electricity. It is the impurities in the water, such as dissolved salts, which allow water to conduct electricity. It is found that a great indicator of the total level of impurities in fresh water is its electrical conductivity—the efficiency with which water transmits electrical current.

The more impurities it contains, the higher the electrical conductivity. For domestic purposes, the preferred water has a total dissolved solids (TDS) content of less than 500 ppm, or a conductivity below approximately 750 microSiemens (ohm⁻¹).

Water Alkalinity and pH Resistance

Alkalinity: Alkalinity is the measure of water's resistance to reductions in pH when acids...

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...

Topical Excipients

1. Vehicles

• Hydrophobic: Silicones (bentonite, dimethicone), alcohols, hydrocarbons (liquid paraffin, petrolatum), sterols (lanolin), and carboxylic acid esters.
• Cosolvents: Polyols (propylene glycol, glycerin, sorbitol) and esters (polyethylene or polypropylene).

2. Functional Agents

• Emulsifiers: W/O (esters, phenols, mono- or polyesters); O/W (lauryl sulfate, polyoxyethylene sorbitan).
• Preservatives: Phenols (to inhibit microorganism growth).
• Viscosity Agents
• pH Regulators
• Moisturizers
• Antioxidants: BHA, BHT, ascorbic acid.

3. Powder Processing

1. Identify heavy constituents.
2. Sift each component.
3. Mix in a mortar (verify weight) or industrial V-mixer.
4. Sift the final mixture (verify weight).
5. Dosing and distribution: Volumetric dosing.
6. Packaging:

Chemical Nomenclature Rules

This section outlines the basic rules for naming binary and ternary chemical compounds.

Binary Compounds

• Metal Oxides: Oxygen (O) typically has an oxidation state of -2. Formula: M_xO_y (M: metal).
  • Lower oxidation state suffix: -ous.
  • Higher oxidation state suffix: -ic.
• Non-metal Oxides: Oxygen (O) typically has an oxidation state of -2. Formula: NM_xO_y (NM: non-metal).
• Metal Hydrides: Hydrogen (H) has an oxidation state of -1. Formula: MH_x.
• Non-metal Hydrides: Hydrogen (H) has an oxidation state of +1. Formula: H_xNM.
  • Nomenclature term: hydrogen [non-metal root]-ide.
• Binary Acids (Hydrohalic Acids): Non-metal hydrides (often Group 16 or 17 elements) dissolved in water.
  • Nomenclature term: hydro-[non-metal root]-ic acid.
• Binary Salts:

Scientific Prefixes and Submultiples

Understanding scientific prefixes is crucial for expressing very large or very small numbers concisely. Here are common prefixes and their factors:

• Giga (G): 10⁹
• Mega (M): 10⁶
• Micro (µ): 10^-6
• Nano (n): 10^-9
• Pico (p): 10^-12

Understanding Scientific Notation

Scientific notation is a way of writing numbers that are too large or too small to be conveniently written in decimal form. It is commonly used in science, where it is also called "standard form" or "standard index form."

Example: To express 38,000 meters with three significant figures:

38,000 m = 3.80 x 10⁴ m

Gas Volume Variation at Constant Pressure (Charles's Law)

When the temperature of a given mass of gas increases, if the pressure remains constant, the volume...

1. Emulsions: Preparation and Stability

Definition: An emulsion is a biphasic liquid dosage form in which one immiscible liquid is dispersed as fine droplets in another liquid with the aid of an emulsifying agent.

Types: Oil-in-water (O/W) and water-in-oil (W/O).

Methods of Preparation

• Dry gum method: Oil, gum, and water are generally used in a 4:2:1 ratio. Gum is triturated with oil, followed by rapid addition of water to form the primary emulsion.
• Wet gum method: Gum is first triturated with water to form mucilage; oil is then added gradually with continuous trituration.
• Bottle method: Suitable mainly for volatile or low-viscosity oils. Ingredients are placed in a bottle and shaken thoroughly.

Identification and Stability

Identification tests: Dilution...