EQUILIBRIO ION UNIT
Student: Zerpa V. Jose G. School: 49 Chemical Engineering
Ion balance is a special type of chemical equilibrium, characterized by the presence of chemical species in aqueous solution, which produce ions. Producing species in solution are referred loads electrolytes. An electrolyte is any species that allows conduction of electric current. Ionization Ion balance Most crystalline inorganic compounds are formed by ions, i.e. electrically charged particles produced when an atom or group of atoms, lose or gain electrons, resulting in positive or negative ions. Electrostatic attraction holds the ions in the crystal. The molten ionic crystals conduct electricity; also solutions in water or other polar solvents of the ionic substances are electrically conductive, which are named electrolytes. When molten glass solutions or a pair of electrodes is introduced and a potential difference is applied, the ions are directed toward one of the electrodes. Those who go to negative hair, called cathode, are called cations and are positively charged, those who go to the positive electrode or anode, are negatively charged anion.
Expressing the ion balance HCl + H2O --> H3O+ + ClDonde: Keq=[H3O+][Cl-]/[HCl] En el tiempo de equilibrio [HCl] tiende a cero, por ende Keq tiende a infinito cuando la disociación es menor al 100%, se habla de un electrolito débil. Los eletrolitos débiles forman equilibrios verdaderos. Ejemplo: HF + H2O <==> H3O+ + FEsta reacción no se completa, alcanza cierto equilibrio, con cierta constante, por eso debe llevar dos medias flechas en direcciones opuestas (flecha doble) donde: Keq=[H3O+][F-]/[HF] como la disociación no es completa, en el tiempo de equilibrio, [HF], [H3O+] y [F-] permanecerán constante, por ende estamos en presencia de un equilibrio químico.
Classifying the properties of aqueous solutions Origin: Water is called the solvent of the millennium, due to the large number of components that can be dissolved in it and its great mixability. The water soluble compounds are those of the ionic group such as sodium chloride, and on the other hand, the less soluble are the covalent group, as the insoluble metals. Water is the most abundant human biomolecule constitutes 65-70% of total body weight. This ratio should remain very close to these values to maintain water homeostasis, for otherwise the body is against pathological situations due to dehydration or fluid retention. The importance of studying the biomolecule water lies in the fact that the totality of the biochemical reactions are performed within the water, all nutrients are transported within the water.
General properties of aqueous solutions: Electrolytic properties: all solutes dissolve in water are grouped into two categories: Electrolyte is a substance that, when dissolved in water forms a solution that conducts electricity.
Not electrolytes: not conduct electricity when dissolved in water These can be classified as: ď ś Electrolitos Strong: the solute is 100% dissociated in susiones. Weak. ď ś Electrolitos: the solute does not dissociate into ions intheir 100%.
Identify the different acid-base theories
The Lewis Theory Another theory That Provides a very broad definition of acids and base hasbeen put forth by the American chemist Gilbert Lewis. The Lewis theory define an acid as a compound That can accept a pair of electrons and a basis as to compound That can donate a pair of electrons. Boron trifluoride, BF 3 , Can be Considered a Lewis acid and ethyl alcohol-based can be Considered Lewis.
The Arrhenius Theory Svante Arrhenius was a Swiss chemist who while still a student, he investigated the conductive properties of electrolytic solutions (leading load). In his doctoral thesis he formulated the theory of electrolytic dissociation. He defined as chemicals acids containing hydrogen dissolved in water and produce a concentration of hydrogen ions or protons, greater than that in pure water. Similarly, a base Arrhenius defined as a substance dissolved in water produced an excess of hydroxyl ions, OH-. The neutralization reaction is: OH- + H + H2O
Arrhenius theory has been criticized. The first is that the concept of acids is limited to hydrogen containing species and species base containing hydroxyl ions. The second criticism is that the theory only relates to aqueous solutions, when in fact many acid-base that occur in the absence of water reactions known.
The Bronsted-Lowry Theory Johannes Bronsted Nicklaus, Danish chemist, born in Varde.Sus most important work was in the field of thermodynamics. Thomas M. Lowry (1847-1936) was a British chemist who, along with Johannes Bronsted announced a revolutionary theory as a result of experiments with acids and bases in solution, which defied the classical definition of acids and bases unrelated to create a new concept of conjugate acid-base pairs. Arrhenius definitions of acids and bases are very useful in the case of aqueous solutions, but by the 1920s the chemicals were working with solvents other than water. They found compounds acting as bases but no OH in their formulas. A new theory is needed.
Consider determining the difference in pH and the strength of and electrolyte There are two classes of chemical compounds interrelated and are very important in everyday life. It is about acids and bases. Some acids are well known vinegar (acetic acid), vitamin C (ascorbic acid) and the battery acid (sulfuric acid). Very common ground lye (sodium hydroxide), the baking soda (sodium bicarbonate) and ammonia. A special type of electrolyte is constituted by acids and bases. Traditionally acids are characterized by having a sour taste, corrode metals, redden litmus paper and lose all their acidic properties upon contact with a base. On the other hand, the bases are characterized by bitter, soapy feel, color blue litmus paper and lose all their properties upon contact with an acid.