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

Fundamental Concepts in Physical Science

I. Atomic and Chemical Structure

Basic Constituents of Matter

Atom

The basic or fundamental constituent of matter.

Element

A species of atoms having the same number of protons in their atomic nuclei.

Molecule

An electrically neutral group of two or more atoms of the same element held together by chemical bonds.

Compound

An electrically neutral group of two or more atoms of different elements held together by chemical bonds.

Ion

An atom or molecule in which the number of electrons is not equal to the number of protons. (Note: Extracting electrons can lead to plasma.)

Isotope

An element made up of atoms that have the same number of protons (atomic number) but a different number of neutrons (mass number).

Periodic Table

Biophysics Fundamentals

Biophysics is a branch of biology that studies the physical phenomena produced inside the cellular plasma.

1. Systems of Dispersions

A dispersion is a mixture of two substances in which one completely surrounds the other without settling. It consists of two phases:

• Dispersed phase: The solute.
• Dispersing phase: The solvent.

Classification of Dispersions

Dispersions are classified into three groups, including suspensions and emulsions.

Molecular Solutions

A solution or molecular dispersion is a mixture where both phases are closely linked to form a homogeneous, transparent substance.

Concentration of Solutions

Solutions are categorized by their solute concentration:

• Saturated: Contains the maximum amount of solute possible to dissolve.

Its function is to complete the measurement circuit, providing a passage from the conductivity-sensing electrode, through the solution, to the reading device. The four parts form an electrical circuit.

Types of Electrodes

1. Hydrogen Electrode
2. Calomel Electrode: Consists of a mixture of mercury and mercurous chloride in contact with a potassium chloride solution.
3. Silver Chloride Electrode
4. Glass Electrode:
   • Parts: Lead-plated, resin-filled rod, internal electrode, sensitive glass.
5. Glass Electrode and Calomel: External calomel reference, two different cells connected in series.

Analysis Methodology

To analyze a substance using potentiometric techniques (anions, cations, organic and inorganic), the substance, or some of its possible complexes, must be electroactive...

Antisepsis, Disinfection and Sterilization

Antisepsis: lowers organic surface microbes. Toxic disinfectants like those used on skin are antiseptics. Antisepsis substances inhibit the development of bacteria and are useful on skin. Antisepsis preserves sterility.

Disinfection: destruction of pathogenic microorganisms, classified by materials, inorganic in nature. Effectiveness levels:

1. High-level disinfection: kills all microorganisms.
2. Intermediate-level disinfection
3. Low-level disinfection: kills only some vegetative bacteria, fungi and lipid viruses.

Disinfectant: destroys non-sporulated organisms and their spores.

Sterilization: destruction of all forms of microorganisms, including their spores.

Sterilization cycle: heat generation over a defined time....

Electrochemical Cells: Batteries and Redox

In a voltaic pile, a spontaneous redox reaction produces energy. Conversely, in an electrolytic cell, a redox reaction occurs only when external energy is provided.

Commercial Battery Types

• Primary Batteries: Reactants are consumed during the reaction; once depleted, the battery is exhausted.
• Secondary Batteries: These are rechargeable; the reaction can be reversed by applying an external current.
• Fuel Cells: Combustion occurs via redox reactions, with hydrogen-oxygen (H₂-O₂) cells being the most common.

Corrosion of Iron

An iron plate undergoing corrosion shows specific areas where the metal is attacked. Corrosion accelerates under the following conditions:

• Contact with seawater.
• Presence of a strong electrolyte.

The Scientific Method and Metric Measurements

1.Know and understand The steps in the scientific method.

Making observations

Asking questions

Proposing answers

Testing the hypothesis

Accepting or rejecting the hypothesis

Repeating the test

2.Understand what is Meant by a controlled experiment.

3.What is the Difference between a control group and an experimental group?

Control group- Never changes

Experimental groups- Dependent and independent Variables

4.Know the metric units Of measurement and how to convert from one unit to another.

10^3 kilo, 10^0 unit, 10^-1 deci, 10^-2 Centri, 10^-3 Mili, 10^-6 Micro, 10^-9 Nano

5.What do the following Instruments measure: pipette-volume, Metric ruler length, beaker- volume, triple beam balance- mass, graduated cylinder-...

The Life of British Naturalist Charles Darwin

Charles Darwin was a British naturalist who revolutionized the science of biology through his demonstration of evolution by natural selection. Darwin's seminal work, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle of Life, was published on November 24, 1859.

Charles Darwin was born in Shrewsbury. His grandfather, Erasmus Darwin, was a scientist whose ideas on evolution anticipated later theories. In 1827, he started theology studies in Cambridge. His love for collecting plants, insects, and geological specimens was noted by his botany professor, who arranged for his talented student a place on the surveying expedition of the HMS Beagle...

What is an Inorganic Compound?

Inorganic compounds are substances formed by various chemical elements. Unlike organic compounds, the main component in inorganic compounds is not always carbon. Water is the most abundant inorganic compound. Almost all known elements can be involved in the formation of inorganic compounds.

History of Inorganic Chemistry

• The beginnings of inorganic chemistry trace back to the history of civilized man. Since the early metal ages, people have been devoted to understanding the minerals in deposits and how they react under certain conditions.
• Later, during the Middle Ages and Renaissance, significant knowledge was gained through the pursuit of a reaction that could lead to gold from other metals. This practice was known

Density of States

Density of states: Each value of K determines an orbital state of e-, double degeneracy due to spin. It is agreed that:

1. The electronic states always include spin degeneracy.
2. When an electron current is assumed, the electron charge of each spin is always included.
3. Electron density N is defined as the total number of electrons per unit volume.

Now the following is discussed:

1. E is a quantized continuous distribution of values, as the quantized E is increased by small integer steps of K, leading to small ΔE of the order of h².
2. Given the continuous distribution of E, the probability of a particular value of E must be zero.
3. We define the density of states n(E), which is the density of energy electrons in the range around energy E per unit

Fundamentals of Electricity

Etymology and Early Observations

Electricity originates from the Greek word "elelctron," meaning "amber." This name was given because the Greeks observed that fossil resin used in jewelry, when rubbed, attracted light objects.

Thales' Discovery

Thales noted that when amber was rubbed with force using cloth, silk, wool, or skin, it would attract light materials.

William Gilbert's Contribution

William Gilbert observed that this attractive behavior was not limited to amber and similar substances. He recognized these phenomena as electrostatics.

Causes and Natural Phenomena

These electrostatic phenomena are caused by the behavior of atoms in each material. Natural phenomena associated with electricity include:

• Lightning storms.