Chemical Reactions in Science and Technology

TECHNOLOGY

MICHAEL JOHN UGLO
This is the fifth lecture in the science in action series on matter focusing on chemicals and chemical reactions. Prior to this, one point to note is that, as you come of age you may become wiser or not at all. Disobedience and rebellion are two most undesirable traits that creates more problems than solving them. If anyone wants to solve a problem, you will be better of staying within a given confinement to create and recreate those changes which saves time, costs, money than to endeavor to create your own.
See, you are ambitious to do something and all support and authority will be accorded to you because you are capable creating those changes. Only time will tell if you were capable. This presupposes, you are better of staying within the confines to demonstrate your capabilities, potentials and your true self.
Chemicals
Chemical refers to the make-up of a substrate by a particular substance. It is about the study of matter and reagents formed either naturally or artificially.
The basic part of matter being the atoms can be used or manipulated to make different substances for different uses. These can form substances called the chemicals.

Substances go through a process called chemical reactions to acquire their usefulness.
These are the basic start up states that combine different substances called reactants or reagents to combine with the presence or without the presence of a source of energy to produce end results called the products.
This is shown by a chemical equation.
The products behave differently to the parent materials from which they are made.
Chemical reactions include the transfer, acceptance and sharing of electrons to form new compounds with parent materials intact, radioactive decay of nuclear reactions and sub-atomic particle known as elementary particles involved in the quantum field theory.
These are all chemical reactions.
Chemical reactions that proceed in living organisms are called biochemical reactions.
These involve proteins as enzymes which are also known as organic catalysts.
Those chemical reactions are called metabolisms in which the energy produced from glucose into a chemical substance called ATP (or adenosine-triphosphate) is used to power up all chemical reactions taking place inside a living cell.
The metabolism inside a living cell is a cycle as one product form one chemical reaction becomes as a substrate to another chemical reaction unique to temperature and substrate or reactant concentrations inside a living cell which cannot happen outside of a living cell.

The chemical reaction can proceed in forward as well as in reverse directions. The reactions that happen in a forward direction may not require energy like heat to do so.
These can be called spontaneous reactions. The exergonic or exothermic reactions release energy.
Non-spontaneous reactions can require energy to do so.
Such reactions include electroplating and charging of a battery that require external sources of electrical energy to empower it to happen.
Photosynthesis also requires absorption of sunlight energy to do so. These particular reactions are called endothermic reactions.
The most common chemical reactions are redox reactions. Redox reactions involve transfer and acceptance of electrons to form new products with different chemical properties although the parent elements remain unaffected. I
n nuclear reactions, there is formation of new elements because the nucleus breaks up and forms nuclides of new elements as in radioactive decay and interactions of elementary particles as described in the quantum field theory.
Four of the main chemical reactions that take place are single and double displacement reactions, Synthesis, dissociation and combustion reactions. In single displacement reactions, one metallic element in its salt state and in solution state as copper sulphate solution can be easily displaced by any metallic element that is more reactive such as iron. For instance, copper can be displaced or replaced by iron forming iron sulphate solution and copper is displaced and become what is known as spectator ions. Those elements higher in the reactivity series are more reactive than those below them and can easily replace them in the case of iron and copper as mentioned above. Such as A + BC = AC + B

In double displacement reactions the positive ions and the negative ions swap positions. That is AB + CD = AD + CB.

In Synthesis reactions A + B = AB

In a dissociation or decomposition reaction AB = A + B

Combustion reaction always involves oxygen to emit heat or light. It is always burning of hydrocarbon compounds. The by-product is always water and carbon dioxide in complete combustion. In incomplete combustion, carbon monoxide is produced instead of carbon dioxide. Combustion can also take place with oxygen, magnesium and sulfur producing magnesium oxide and sulfur dioxide.
The chemical reactions in redox, complexation, acid-base, precipitation, solid-state reactions, photochemical reactions and the reactions at the solid/gas interface are all happening in nature or in controlled environments.
Chemical reactions also take place with the use of catalysts. Catalysts speed up reactions and are not used up themselves. They can be used over and over again.
There is so much chemical reaction taking place in organic chemistry or chemistry of the living world such as in plants and the animals’ are the biochemical systems for metabolism and anabolism. In the olden days it was hard to study organic chemistry until urea was synthesized. Then mineral acids were made followed by the synthesis of ammonia through the Haber process.

The chemical reactions in the living systems use the energy derived from glucose to make a chemical compound known as the ATP or adenosine-triphosphate to power the chemical reactions. The product of one chemical reaction inside a cell becomes the reagent for another chemical reaction that follows and so on. These cycles of chemical reactions are unique inside a cellular environment with its specified temperatures and concentrations that cannot happen under normal external conditions.

My Prayer for PNG today is: “All that we have and all that we offer. Comes from a heart, both frightened and free…”

Next week: Acids, Bases and Salts in Science and Technology

Presenter: Michael John Uglo – Science Textbook Author “Science in PNG, Pacific, Asia & Caribbean” & Lecturer in Avionics, Auto- Piloting & Aircraft Engineering)

Note: Please send your sentiments and comments to my email: [email protected]