Current Page: Chem4Kids.com | Reactions | Overview

Let's start with the concept of chemical reaction. Reaction occurs when two or more molecules interact to change molecules. The bond between the atoms is broken to form a new bond. However. What are those molecules? How do they talk? What's wrong? The possibilities are endless

Imagine you are using it when you are trying to understand a chemical reaction. Imagine there is a building block on your front table. Sometimes we use chemical toys to help imagine the movement of atoms. Reseat the small connector representing the chemical bond. There are several important points to know about chemical reactions.

A chemical change has to occur. You start with one molecule and then turn it into another. Make chemical molecules or destroy them to make new molecules. An example of a chemical reaction is rust of a steel trash can. The cause of rust is that iron (Fe) in the metal bonds with oxygen (O 2) in the atmosphere. It forms and destroys chemical bonds and ultimately forms iron oxide (Fe 2 O 3)

Even if the refrigerator or air conditioner cools the air, molecules in the air will not react. The change in temperature is a physical change. This is a physical change when melting ice. When you put bleach in the washing machine to clean clothes, chemical change can destroy molecules of dirt

The reaction may comprise a single element atom, ion, compound or molecule. It is necessary to remember that anything can react chemically as long as chemical changes occur. If pure hydrogen (H 2) and pure oxygen are placed in the room, they may participate in the formation of water (H 2 0). However, the number is very small. When sparks are added, these gases undergo a violent chemical reaction, causing a huge explosion (fever). Other chemical reactions may include silver ions (Ag +). When a solution containing silver ions is mixed with a solution containing chloride ion (Cl -) ions, silver chloride (AgCl) precipitates and falls from the solution.

A single reaction often occurs as part of a series of reactions. When plants produce sugar, there are dozens of chemical reactions through the Calvin cycle and may ultimately produce (synthetic) glucose (C 6 H 12 O 6) molecules. An example of a previously used rust shows only the original reactant and the final product of the chemical reaction. There are several intermediate reactions that generate and destroy chemical bonds. An example of silver chloride focuses on ions only. Indeed, when two salts dissociate in water (when it is divided into ions), two solutions are produced.

Chemical reactions are an important part of chemical reactions. This article outlines this broad topic. It understands the history and future of chemical reaction well. I hope that the expansion of chemistry and our knowledge will not end. As scientists are still experimenting, chemical reactions will always be part of chemistry.

If the change in the total entropy of the universe induced by the reaction is not negative, the chemical reaction will proceed naturally (or possibly progress). As discussed in the introduction, Gibbs free energy is the (negative) factor of the total entropy change in the universe if the temperature and pressure remain constant. S has a negative coefficient in the representation of G, so Gibbs free energy moves in the opposite direction to total entropy, so this is "negative". Therefore, reaction with positive Gibbs free energy does not occur spontaneously. However, in biological systems (and others), energy inputs from other energy sources, including solar and exothermic chemical reactions, are "coupled" to non-entropy potential reactions (ie Gibbs free energy exceeding zero) . Given the coupling reaction, the total entropy of the universe increases. Therefore, the biological system does not violate the second law of thermodynamics.

The energy theory of biochemical reactions is best explained by the thermodynamic function called Gibbs free energy (G) called Josiah Willard Gibbs. Changes in the free energy (ΔG) of the reaction are influenced by enthalpy change (heat released or absorbed in chemical reaction) and entropy (extent of disorder caused by the reaction) in order to predict whether the reaction is energetically favorable . All chemical reactions proceed spontaneously in a direction favoring energy with a decrease in free energy (ΔG <0). For example, consider the hypothetical response that A is converted to B.