Category: General Chemistry Library

• What is a Solution?

  A solution is a homogeneous mixture formed when a solute, typically present in smaller amounts, dissolves in a solvent. Solutions can vary based on the physical states of the solute and solvent, leading to liquid, solid, and gaseous solutions.

• How to Determine the Limiting Reagent in a Chemical Reaction?

  The limiting reagent, is consumed first during the reaction. It is termed “limiting” because it limits the extent of the reaction.

• How to Convert Between Moles and Grams?

  In the world of chemistry, the ability to convert between moles and grams is a fundamental skill for chemical calculations and analyses.

• What is The Mole and How Many Atoms are There in One Mole?

  In the laboratory, we need a unit that can be used for practical measurements. For this purpose, we use the unit mole, which can later be converted to grams. The mole is a unit of measurement that is used to count the number of atoms, molecules, or ions in a substance. One mole of any…

• How to Calculate Average Atomic Mass?

  The mass of atoms depends on the number of protons, electrons and neutrons they contain. As atoms are extremely small, it is impossible to weight them using normal units.

• Trend of Atomic Radius in Periodic Table

  Learn Trend of Atomic Radius in Periodic Table

• Balance redox equations (reaction of copper with potassium permanganate)

  Learn balance redox equations (reaction of copper with potassium permanganate). Copper reacts with potassium permanganate is an example of redox reaction in which copper oxidation state changes from zero to +2.

• The Electrons and Cathode-Ray Tube

  The atom is the basic unit of any substance. The atom consists of three main components. Protons, neutrons, and electrons.

• Dalton’s Atomic Model

  Dalton revived Democritus postulation when he found that each time tin reacts with oxygen gas to give tin oxide they react with a ratio 1:2 (tin : oxygen). From that he assumed that each tin and oxygen must contain small particle that take a place in the chemical reaction.

• Calculating Lattice Energy For Al2O3

  Calculate the value for the lattice energy of aluminum oxide and energy diagram for aluminum oxide

• Lattice energy and Lattice Enthalpy

  When positive and negative ions come together to form the crystal lattice an amount of energy is released, we name it “lattice enthalpy” ΔHꝊlatt.

• Nitrogen and Nitrogen Compound

  Nitrogen is located in the group 15 second period. Nitrogen electronic configuration: 1s22s22p3 Nitrogen’s physical properties: Why is nitrogen gas unreactive? The reaction of nitrogen with oxygen under extreme conditions: N2(g) + O2(g)  →    2NO(g) (Nitrogen oxide) Nitrogen oxide oxidizes into nitrogen dioxide. 2NO(g) + O2(g)   →   2NO2(g)    (nitrogen dioxide) Once it is formed, it…

• Empirical formula and ionic formula

  The empirical formula: An empirical formula is the formula that represents the simplest whole number ratio of atoms in an element. For example: Hydrazine’s molecular formula is N2H4 We can obtain the empirical formula by dividing the molecular formula by two to obtain the simplest ratio. By that, we get that the empirical formula of…

•  Periodic Table of Elements

  The modern periodic table contains 118 elements, where elements from 95 to 188 are synthetic elements.

• What are molecules? and Ions?

    Except for noble gases, all elements are found in nature not as single atoms but as groups of atoms bonded together. Two or more atoms that are joined by chemical bonds make up a molecule. Molecules can be formed from identical atoms, which are elements.For example, one molecule of oxygen gas consists of two…

• Atomic Number, Mass Number and Isotopes

  Atoms consist of a nucleus where the mass of the atom is concentrated. The nucleus contains the positive protons and neutral neutrons. In the vast space around the nucleus, the negatively charged electrons are located. Each element has a distinct number of protons; we often call it the atomic number. No two elements have the…

• The Discovery of Neutrons and Rutherford Gold Foil Experiment

  After the discovery of radioactivity, it was observed that radioactive elements, such as uranium, emit spontaneous radiation as a result of their radioactive decay. There are three types of radiation emitted during radioactive decay: In 1910, Ernest Rutherford, a New Zealand physicist and former student of J. J. Thomson, embarked on a study of the…

• Millikan Experiment to Obtain the Charge of an electron

  How to obtain the charge of an electron? The first to obtain the electron charge and mass of an electron was Millikan. In his experiment, he used: Two charged plates in which the positive plate is placed at the top and has a tinny hole. Then he fired a mist of tiny oil drops using…

• The Discovery of the Atom and Dalton’s Atomic Theory 

  The ancient Greek philosopher Democritus proposed a groundbreaking idea regarding the nature of matter. He hypothesized that all substances are comprised of incredibly tiny, indivisible particles, which he aptly named “atomos” meaning “uncuttable” or “indivisible.” To illustrate this concept, consider the example of an apple. If we were to slice the apple into smaller and…

• States and Classification of Matter

  Matter refers to any substance that possesses mass and occupies space, or in other words, has volume. This broad definition encompasses everything in our surroundings, including ourselves. Even the air that surrounds us is classified as matter since it has both mass and occupies a specific volume. Everything around us is considered a matter: To…