Step into the Generalities in Chemistry, where the foundations of this diverse field are explored. Delve into the fundamental principles and concepts that underpin the study of matter and its transformations. From atomic structure and chemical bonding to states of matter and chemical reactions, uncover the key elements that shape our understanding of chemistry. Embark on a journey of discovery as you unravel the secrets and intricacies of this fascinating science.
Oxidation-reduction concept Initially, these processes were understood as follows: Oxidation: addition of oxygen to a substance. Reduction: Loss of oxygen from a compound, resulting in a reduction in mass: If the reaction of zinc in the first process is compared with the following: It can be seen that the following transformation has taken place in … Read more
What are the colligative properties of solutions? When a solute is dissolved in a solvent, some properties of this solvent are modified, such as vapor pressure, boiling point, melting point and osmotic pressure. These properties are known as colligative properties. The extent to which these modifications occur will depend on both the concentration and the … Read more
What is electronegativity? The concept of electronegativity is originated from the experimental observation, for example, elements such as chlorine and fluoride exhibit a very strong tendency to give negative ions. On the other hand, other elements in group I, as there are electronegative, and is best described as electropositive (tendency to form positive ions). This … Read more
What is the oxidation number? The oxidation number also known as oxidation state is the fictitious electrical charge that is assigned to an atom. It is used to indicate the possible net charge of the same, and a possible method of accounting of electrons. For example, it is used to know whether a reaction is redox … Read more
What is an acid-base indicator? An acid-base indicator is an organic substance that changes color when the pH of the medium in which it is found changes. They are generally weak acids or bases whose dissociation equilibrium is shifted to the left or to the right depending on the [H+] and that present different color … Read more
Enzymes are important proteins whose function is to accelerate the speed of chemical reactions that occur in the body and that are necessary to maintain their biological activity, which they do by decreasing the activation energy. Enzyme-catalyzed reactions occur at rates 1010 to 1014 times faster than non-catalyzed reactions. For example, urease accelerates the hydrolysis … Read more
Suspended particles have a size smaller than 10 microns. They are made up of a multitude of different pollutants. These particles remain stable in the air for long periods of time without falling to the ground and can be carried by the wind over long distances. Particle origin and formation Particulate matter smaller than 10 … Read more
Water is necessary for life on earth and therefore its quality is of great importance. When the pH of precipitation is less than 5.6 we call it acid rain. Emissions of two atmospheric pollutants, NOx and SO2 are the main cause of acid rain formation. While in Europe and North America such emissions are decreasing, … Read more
Photochemical Smog is the contamination of the air, mainly in urban areas, by ozone caused by photochemical reactions and other compounds. The result is a reddish-brown atmosphere. Ozone is an oxidizing and toxic compound that can cause respiratory problems in humans. This type of smog was first described in Los Angeles in the 1940s, and … Read more
Carbon monoxide (CO) is a colorless, odorless and toxic gas. It is a product of incomplete combustion of hydrocarbons. Its molecule is composed of one carbon atom and one oxygen atom. Health hazards If inhaled, carbon monoxide replaces the oxygen that cells need to function. Carbon monoxide in the air builds up quickly in the … Read more
