Equilibrio ion unit

EQUILIBRIO ION UNIT

Schoolgirl: Azuaje S. Roxi A. School: 49, Chemical Engineering ENGLISH II

EQUILIBRIO ION UNIT

Ionic balance The bal brioIonic or this is one tip oresp eci toof equ ili bri orere mic orcar act eri Func orabout the presence of chemical species in aqueous solution, which produce ion species in solution produced charges are called electrolytes. An electrolyte is any species that allows conduction of electric current. โ ข Acids and Bases In 1923, two scientists named Johannes TMLowry N.Brรถnsted and well characterized acids and bases: Acid: It is the substance that can donate protons. Base: Is the substance capable of receiving proton. So between an acid and a base given there a certain ratio by exchanging protons.

This exchange is what makes them good acids considered either bases.

Issyst ema acid-bas eConjug ado. Itform ula asreaction It proto lisi s ofthe following manner: ACID <----> PROTON + CONJUGATE BASE.

Classifying the properties of aqueous solutions

When a solute to a solvent is added, some physical properties of the solvent remain unchanged. By increasing the amount of solute, the boiling point rises and lowers the freezing point. So, to prevent freezing of the water used in the cooling of automobile engines, is added antifreeze (solute). But when a solute is added to the solvent vapor pressure is lowered.

Another remarkable property of a solution is its ability to exert osmotic pressure. If split two solutions of different concentrations by a semipermeable membrane (a membrane that allows passage of solvent molecules, but prevents the passage of solute), the solvent molecules pass from the less concentrated solution to more concentrated solution , making the latter more dilute.

* Solute particles are smaller than in other kinds of mixtures. * They present a single phase, that is, they are homogeneous. * If allowed to stand for a while, the phases do not separate or sedimentation is observed, ie the particles do not settle to the bottom of the container.

Identify the different acid-base theories

Acid-Base Theories There are three theories to identify identity That Which unique characteristic define an acid and base: the Arrhenius theory, for the Swedish chemist Svante Which WAS Arrhenius Howard Shore wins Film Prize in chemistry Nobel 1903; the Bronsted-Lowry, or proton donor, theory, advanced in 1923; and the Lewis, or electron-pair, theory, Which Was Also Presented in 1923. Each of the three theories Has Its own advantages and Disadvantages; Useful each is under Un certain conditions.

The Arrhenius Theory When an acid dissolves in water based or, in Un certain percentage of the acid or basic particles will break up, or dissociate (see dissociation ), into oppositely charged ions. The theory Arrhenius define an acid as a compound That can dissociate in water to yield hydrogen ions, H + , and as a base compound That can dissociate in water to yield hydroxide ions, OH - â&#x20AC;&#x160;. For example, hydrochloric acid, HCl, dissociates in water to yield the required hydrogen ions, H+, And Also chloride ions, Cl - â&#x20AC;&#x160;. The basic sodium hydroxide, NaOH, dissociates in water to yield the required hydroxide ions, OH - , And Also sodium ions, Na+.

The Bronsted-Lowry Theory Some Substances Act as acids or base When They are Dissolved in solvents other than water, liquid: such as ammonia. The Bronsted-Lowry theory, named for the Danish chemist Johannes Brรถnsted and the British chemist Thomas Lowry, Provides more general definition of acids and base That can be Used to Deal With Both solutions That Contain no water and solutions That Contain water. It define an acid as a proton donor and base as a proton acceptor. In the Bronsted-Lowry theory, water, H 2 O, can be Considered an acid or base since it can lose a proton to form a hydroxide ion, OH - , or accept a proton to form a hydronium ion, HThreeO+(See amphoterism ). When an acid Loses a proton, the remaining species can be a proton acceptor and is called the basis of the conjugate acid.

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.

Consider determining the difference in pH and the strengthof and electrolyte

Strong and weak electrolytes Although there is a large amount of electrolyte in nature, not all behave in the same way. For example, if a 1 M hydrochloric acid (HCl) and a 1 M solution of acetic acid (CH3COOH, as vinegar), the first electric current best lead is prepared. Both molecules dissociate in water forming a H + cation and an anion (Cl- and CH3COO-, respectively).

Why then do these substances do not conduct current like? The difference is that while all the molecules dissociate hydrochloric acid to generate ions, only 0.4% of acetic acid molecules make; others do not dissociate. This means that only 4 out of every 1000 molecules of CH3COOH generate ions. Acetic acid is a weak electrolyte, the electrolyte that completely dissociate in water, such as HCl or NaCl, are called strong electrolytes.

Strength of acids and bases A strong electrolytes that have acidic or basic properties are also called strong acids or respectively bases. Of course, there are weak acids or bases if electrolyte is not completely dissociated in aqueous solution.

Other examples of strong acids are sulfuric acid (H2SO4), nitric acid (HNO3) and hydrobromic acid (HBr). A weak acid is citric acid which is found in fruits, such as orange or lemon.

THE pH The acidity or basicity of a solution depends on the amount of cations H + and OHanions having; that is, depends on the ion concentration. Therefore a 1M strong acid, such as hydrochloric acid (HCI) solution is more acidic than a solution of the same molar concentration, but of a weak acid such as acetic acid (CH3COOH).

To distinguish the acidic solutions of the basic solutions, a fundamental rule followed in the molar concentration of ions in solution. If the concentration of H + ions is higher than that of 0H- ion solution is acidic. If instead 0H- ion concentration is higher, the solution is basic or alkaline.

[H +]> [OH-] acid solution [H +] <[OH-] basic solution

pH> 7 basic solution pH <7 acidic solution neutral solution pH = 7