Notes, abstracts, papers, exams and problems of Chemistry

ACID OR BASES: Substances that react with each other according to the following reaction

Nomenclature

Nomenclature: Binary ionic compounds involves combining the names of the compound’s positive and negative ions. The name of the cation is given first, followed by the name of the anion.
Binary compounds: Compounds composed of two elements.

Systems

Stock: uses a Roman numeral to indicate an Ion's charge.

Systematic: naming molecular compounds based on the use of prefixes.

Traditional: the latin names of chemical elements.

Types of Inorganics

Binary Ions: monatomic+monatomic

Ternary Ions: monatomic + polyatomic

Binary Acids: H + monatomic ( Hydro- & -ic acid )

Ternary Oxyacid: H +polyatomic ( -ate, -ide → -ic acid) ( -ite → -ous acid)

Metal oxides

The Mole Concept

The mole concept is an International System unit of measurement for a substance. It is also represented by carbon-12, and 1 mole is equal to Avogadro's number (6.022 x 10^23).

The Periodic Table's Role in Stoichiometric Calculations

We use the periodic table to get values for given elements in a reaction to obtain their atomic values. We can then use these values for conversion from grams to moles or moles to grams in stoichiometric-based problems (gram/mole, mole-gram conversions).

Heat vs. Enthalpy

Heat is the energy that flows between a system and its surroundings due to a difference in temperature.

Enthalpy is equivalent to the total heat content of a system.

Why Only Enthalpy Explains Energy Associated with Chemical Bonds

Because... Continue reading "Principles of Chemistry: From Stoichiometry to Molecular Orbital Theory" »

Fluorine (F): -1

Chlorine (Cl), Bromine (Br), Iodine (I): 1, 3, 5, 7

Sulfur (S), Selenium (Se), Tellurium (Te): 2, 4, 6

Nitrogen: 3, 5

Phosphorus (P), Arsenic (As), Antimony (Sb), Bismuth (Bi): 3, 5

Carbon (C), Silicon (Si): 2, 4

Boron (B): 3

LIthium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), Francium (Fr), Silver (Ag): 1

Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), Radmium (Ra), Zinc (Zn), Cadmium (Cd): 2

Mercury (Hg), Copper (Cu): 1, 2

Tin (Sn), Lead (Pb), Platinum (Pt), Iridium (Ir), Titanium (Ti): 2, 4

Iron (Fe), Cobalt (Co), Nickel (Ni): 2, 3

Gold (Au): 1, 3

Manganese (Mn): 2, 3, (4, 6, 7)

Aluminium (Al): 3

Chromium (Cr): 2, 3, (6)

Chemistry and Physics Basics

Chemistry

The study of the composition, structure, and properties of matter.

Physics

The study of the principles of matter and energy.

Earth Science

The study of Earth and its neighbors in space.

Matter and Its Properties

Mass

A measure of the amount of matter.

Matter

Anything that has mass and takes up space.

Atom

The smallest unit of an element.

Element

A pure substance that cannot be broken down into simpler substances, made up of atoms.

Compound

Made up of elements and can be broken down into simpler substances.

States of Matter

• Liquid: A state of matter that has a definite volume but not a definite shape.
• Gas: A state of matter with no definite volume or shape.
• Plasma: A high-temperature state of matter in which atoms lose most

Tension is a type of stress that a structural element experiences when subjected to two equal and opposite forces pulling outwards along the same axis.

These forces:

• Act on either side of the element.
• Are equal in magnitude.
• Are aligned along the element's axis.
• Pull in opposite directions.

If these forces deform the element, it will stretch. If the element fails, it will break in the middle, perpendicular to the force direction.

Compression is a type of stress that a structural element experiences when subjected to two equal and opposite forces pushing inwards along the same axis.

These forces:

• Act on either side of the element.
• Are equal in magnitude.
• Are aligned along the element's axis.
• Push in opposite directions.

If these forces deform the element,... Continue reading "Structural Element Behavior Under Different Forces" »

- Without H20 being polar, there would be no life on Earth, and Earth will be very dry. Humans and living organisims depend on H20 and it's polarity to sustain life on Earth because h20 wouldnt be able to form hydrogen bonds because it isnt polar. Animals who depend on ice such as polar bears and seals wold not be able to live due to ice not floating on the surface of water. When ice lacks crystal lattice structure, it starts to drown, and this happens due to the lack of hydrogen bonding. Therefore, h20 is very important for life to exist on earth.

- h-h: nonpolar covalent bond

- p-cl: covalent

- na-br: ionic

Electronegativity: 0->0.4 = covalent, 0.5->1.7=polar covalent, more than 1.7= ionic bonds, minus the EN

- Ion-induced dipole force:

DISTILATION PROCESS: ELEMENTS

• Thermometer: measure the temperature of the vapor
• The stopper: hold the thermometer
• The Bunsen Burner: heat the liquid
• The tube at the top of the condenser: conduct the cool water away
• The cool water: cool the vaporized alcohol
• The tube at the bottom of the condenser: conduct cool water in
• The receiving flask: collect the condensed alcohol
• The stand (soporte): maintain an upright or vertical position
• The clamps (pinzas): support the wire
• The wire gauze (rejilla de alambre): spread the flame out
• The ring clamps (pinzas de anilla): grip the flask and the condenser

ORDER

1. Distillation is used...
2. To separate a mixture of liquids...
3. Distillation is a widely used method...
4. The gas is then condensed...
5. Although the term is mostly common.

What is an atom?

Atoms are the basic units of matter and the defining structure of elements.

What is an electron?

A subatomic particle with a charge of negative electricity.

What is the nucleus of an atom made of?

Is made up of protons and neutrons.

What is a proton?

Elemental particle of the nucleus of the atom and that has a positive electric charge.

What is a neutron?

A subatomic particle of about the same mass as a proton but without an electric charge.

Where is the mass of an atom concentrated?

In the nucleus most of 99.9% of the mass is concentrated here.

An atom is mostly empty space?

Yes.

What is the function of neutrons?

To allow protons to be together.

What surrounds the nucleus of an atom?

The nucleus is surrounded by electron clouds that produce... Continue reading "Understanding Atoms and Quantum Mechanics: A Comprehensive Guide" »