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

Conjugate Acid-Base Pairs

The CN⁻ ion is a base because it is capable of accepting a proton to form HCN, its conjugate acid:

CN⁻ + H₂O ⇌ HCN + OH⁻

The NH₄⁺ ion is an acid because it is capable of yielding a proton to form NH₃, its conjugate base:

NH₄⁺ + H₂O ⇌ NH₃ + H₃O⁺

The SO₄²⁻ ion is a base because it is capable of accepting a proton to form the HSO₄⁻ ion, its conjugate acid:

SO₄²⁻ + H₂O ⇌ HSO₄⁻ + OH⁻

Salt Hydrolysis and Solution pH

Potassium Chloride (KCl)

, is a salt that dissociates in aqueous solution leading to potassium ions (K +) and ions
chloride (Cl?). The chloride ion (Cl?) comes from a strong acid such as hydrochloric acid (HCl) and therefore it is
a weak conjugate base that is not

Organic Reactions

Halogenation Substitution of Alkanes

CH₄ + Cl₂ → CH₃Cl + HCl

Obtaining Alcohol from Halogenated Alkanes

CH₃-CH₂-CH₂-CH₂Cl + KOH → CH₃-CH₂-CH₂OH + KCl

Addition Reactions to Double and Triple Bonds

Hydrogenation

Hydrogen is added to alkenes and alkynes to give alkanes in the presence of a metal catalyst.

CH₃-CH=CH-CH₃ + H₂ → CH₃-CH₂-CH₂-CH₃

Halogenation

Alkenes and alkynes react with halogens to give halogenated compounds.

CH₃-CH=CH₂ + Br₂ → CH₃-CHBr-CH₂Br

Adding Hydracids

Acid hydrogen is added to the carbon with more hydrogens (Markovnikov's rule).

CH₂=CH₂ + HI → CH₃CH₂I

Water Addition

Water is added to alkenes in the presence of acid and also follows Markovnikov's rule.

Voltaic Battery

A voltaic battery is a device that allows an...

Chemical Bonding Fundamentals

Chemical bonding describes how atoms or ions join to form molecules, giant structures, or lattices.

The Octet Rule

Atoms that bond tend to gain, lose, or share electrons until they complete their valence shell with eight electrons.

Primary Types of Chemical Bonds

• Ionic Bonding

  Originates from the electrostatic forces between oppositely charged ions, resulting in the formation of an ionic crystal.

• Covalent Bonding

  Originates when atoms share electrons so that their valence shells are filled, thereby satisfying the octet rule.

Models and Theories of Bonding

• Lewis Model

  The bond is established when attractive forces between atoms are balanced by repulsive forces.

• Standard Electronic Clouds Model

  The charge density between the

Catalyst

A catalyst is a substance present in a chemical reaction that produces a change in its speed without being consumed during its course. It participates in the reaction but is not altered by it. There are positive catalysts that increase the rate of reaction and negative catalysts that reduce the rate of reaction.

Oil

Oil is a mixture of organic substances—liquid, gaseous, or even solid in solution—mainly abundant in hydrocarbons. Simple hydrocarbons, such as methane, exist, as well as more complex ones that can have up to 40 carbon atoms. Organic compounds with oxygen, such as phenols, are also present. Oil is composed mainly of carbon, a lower percentage of hydrogen, and an even smaller percentage of other elements like nitrogen,...

Fundamentals of Electrolysis

Electrolysis is the process in which the passage of electric current through a solution or a molten electrolyte produces a non-spontaneous oxidation-reduction (redox) reaction.

Key Components of an Electrolytic Cell

The electrolytic cell (or container) is the vessel where the process takes place. It holds the solution or molten electrolyte, in which the electrodes are immersed and connected to a continuous (DC) power source.

The electrodes are the surfaces where the oxidation-reduction half-reactions occur. They tend to be inert. Electrodes are distinguished as follows:

• Cathode: The electrode where reduction occurs. In an electrolytic cell, it connects to the negative pole of the power source.
• Anode: The electrode where

Fundamental Atomic Structure

• Atom: The smallest unit of a substance that retains its chemical properties, composed of subatomic particles common to all elements.
• Atomic Number (Z): The number of protons in an atom's nucleus. In a neutral atom, this equals the number of electrons.
• Mass Number (A): The total number of particles in the nucleus (protons + neutrons).
• Isotopes: Varieties of the same element with the same atomic number (Z) but a different number of neutrons, resulting in a different mass number (A).

Chemical Quantities and Formulas

• Mole (mol): The amount of substance containing 6.022 × 10²³ particles, known as Avogadro's number.
• Empirical Formula: Indicates the simplest whole-number ratio of atoms in a molecule.
• Molecular Formula: Indicates

Fundamental Chemical Principles: Acid-Base Theories

Arrhenius Theory: Ionic Dissociation

The Arrhenius theory postulates the existence of positive and negative ions in aqueous solutions of acids, bases, and salts (electrolytes) to explain their electrical conductivity.

Key Definitions in Arrhenius Theory

• Acid: A substance, electrically neutral, that in aqueous solution dissociates into $ ext{H}^+$ ions (protons) and negative ions.
• Base: A substance, electrically neutral, that in aqueous solution dissociates into $ ext{OH}^-$ ions (hydroxide or hydroxyl ions) and positive ions.

Neutralization Reaction (Arrhenius)

According to this theory, the neutralization reaction occurs between an acid and a base, yielding a salt and water.

Brønsted-Lowry Theory:

Types of Materials

Materials are substances whose properties make them useful for the fabrication of structures, machinery, and other products.

Material Classification Groups

Materials are typically classified into groups:

• Metals and Alloys (e.g., iron, steel, aluminum)
• Polymers (e.g., nylon, polyurethane)
• Ceramics and Glass (e.g., alumina, magnesia)
• Composite Materials (e.g., wood, cermets)

Material Properties

Key material properties include:

• Chemical Properties
• Physical Properties
• Mechanical Properties
• Aesthetic and Economic Properties
• Fabrication Properties

Chemical Properties

Chemical properties include behavior related to oxidation and corrosion.

Oxidation

Oxidation occurs when a material combines with oxygen, forming oxides.

Corrosion

Corrosion is a form...

Equi. Homogeneous reactants and products in the same physical state. Equi different heterogeneous. Kc: The law of mass action tells us the equilibrium constant q is the product of the high concentration of the products to their stoichiometric coefficients, divided by the product of the concentrations of the reactants raised to their respective stoichiometric coefficients. The value of Kc is specific for each reaction qiomica and independent of initial concentrations of reactants and products. It just depends on the temperature. T = KC = Degree of dissociation: indicates the amount to as x q open one of reagent reacted. Is the ratio between the amount, expressed in mol, q reagent has reacted and the amount of initial reagent: a = Qc reaction

Basic and Acidic Oxides

METAL + O₂ → a basic oxide. A basic oxide + H₂O → a hydroxide. An oxide can react to form a salt and H₂O.

METAL + H₂O → typically forms a hydroxide (in some cases, hydrides may form).

NONMETAL + O₂ → an acidic oxide (acid anhydride). An acidic oxide + H₂O → an acid; acids can form salts + H₂O in neutralization reactions.

Basic oxides: definition and examples

Basic oxides: These are binary compounds formed by the union of a metal with oxygen.

Basic oxide formation examples: METAL + O₂ → a basic oxide. Examples:

• Na + O₂ → Na₂O
• Ca + O₂ → CaO
• Al + O₂ → Al₂O₃

Formation of hydroxides from oxides

The oxides combine with H₂O to form hydroxides:

• Na₂O + H₂O → 2 NaOH
• CaO + H₂O → Ca(OH)₂
• Al₂O₃ + H₂O → 2 Al(OH)₃ (depending