Overview of acidbase equilibria questions key the following questions are designed to give you an overview of the topics in acids and bases and equilibria in acidbase solutions. Strong bases completely dissociate into their ions. Wed like to understand how you use our websites in order to improve them. Acid base equilibria bronstedlowry definition of acid base behaviour a bronstedlowry acid is defined as a substance that can donate a proton. Practice using curved arrow notation to show the process of acid base reactions bronstedlowry and lewis. At chemical equilibrium, the products and reactants have reached a state of balance.
That means a equilibrium is established and it lies far to the left reactant favored. Practice predicting the direction of equilibrium for. The ability of acids to react with bases depends on the tendency of hydrogen ions to combine with hydroxide ions to form water. Classification of acids and bases lecture video if you have ever tried to get a stain out of a favorite garment or struggled to clean your bathtub after a long period of neglect, this lecture is for you. Strong acids dissociate 100% to ionic form no molecules of acid remain all ions common strong bases know these lioh naoh koh caoh 2 sroh 2 baoh 2 if solvent reduces different reagents to the same strength it is the leveling effect. Every arrhenius acid is a bronstedlowry acid and likewise for the bases. It can be considered an acid in some reactions and a base in others. This tendency is very great, so the reaction in eq 1 is practically complete. If you know these, you will automatically know if something is a weak acid or base. Set up the law of mass action hc 2 h 3 o 2 c 2 h 3 o 2. Acids and bases are everywhere every liquid you see will probably have either acidic or basic traits. Introduction to acidbase chemistry a chem1 reference text stephen k. Chemistry 108 chapter 9 lecture notes acids, bases, and equilibrium 1 chapter 9 lecture notes.
Notes include acidbase definitions, ph calculations for strong acids, strong bases and weak bases, acidbase titration curves and buffer solution calculations. This would be easy to know exactly, except that the ha is not always equal to the concentration of solute that actually went into the solution. Chapter 14 chemical equilibrium chapter 15 aqueous equilibria. Given a chemical equation, write the law of mass action. All acids and bases come with a conjugate paira base or acid, respectively, that is formed in conjunction with the original species. Describes the arrhenius, bronstedlowry, and lewis theories of acids and bases, and explains the relationship between them.
Acids are electron pair acceptors bases are electron pair donors. This model, developed by gilbert lewis, defined acids and bases in terms of electronpair transfer. Unit 8 chemical equilibrium focusing on acidbase systems nelson. Define and identify bronstedlowry acids and bases, and identify conjugate acidbase pairs. A2 chemistry acidbase equilibria teaching resources. The equilibrium expression for acids is known as the ka the acid dissociation constant. Like all equilibria, an acidbase dissociation will have a particular equilibrium constant which will determine. He determined that acids and bases must ionize or dissociate in water. A solution of calcium hypochlorite, a common additive to. An acid dissociation constant, k a, also known as acidity constant, or acidionization constant is a quantitative measure of the strength of an acid in solution.
To find the phpoh, take the logx since x represents the hydronium ion concentration in acids and the hydroxide ion concentration in. Chemistry 108 chapter 9 lecture notes acids, bases, and equilibrium 3 when an equilibrium constant has a value less than 1, the denominator related to reactant concentration of the equilibrium constant expression is greater than the numerator, which means that at equilibrium the reactants are favored more reactants than products. That means a equilibrium is established and it lies far. Can be used as a teaching resource or selfteaching tool. We need to be able to identify acids and bases and understand their properties. Water is present in all acidbase chemistry and is amphoteric in. The quantity most measured in aqueous acid base equilibrium is the oxonium hydronium ion concentration but usually called. Strong acids and bases examples of strong acids are h 2 so 4, hno 3, hcl, hbr, and hi. Weak acids and weak bases acid base equilibrium weak acids and weak bases do not dissociate completely.
Given the equilibrium constant k eq for a reaction, predict whether the reactants or products are predominant. Solve for the rice table x by writing the equilibrium expression, plugging in the values from the equilibrium line of the rice table, and setting it equal to the given k a or k b. Nonadditivity of volumes video pdf acids and bases weak acids and bases hydrolysis of salts video pdf dry ice rainbow of colors video pdf battle of the acids video pdf ammonia fountain with bromthymol blue video pdf acidic, basic and neutral salts video pdf acids and bases buffers bet on buffers video pdf. How do bronstedlowry acids and bases illustrate equilibrium. Monoprotic acidbase equilibria monoprotic acidbase equilibria. Acids and bases chapter 16 applications of aqueous equilibrium chapter 17 thermodynamics. This kind of reaction is called a neutralization reaction. Hints for working acidbase equilibrium problems there are only six equations needed to solve acid base problems. Notice what happens when you get rid of spectator ions for strong acids and bases. Jan 15, 2016 a2 chemistry revision notes on acidbase equilibria. The quantity most measured in aqueous acidbase equilibrium is the oxonium hydronium ion concentration but usually called.
Write the formula of the conjugate base for the following compound. Reactions may still be taking place within the sample, but the forward and reverse reactions are taking place at the same rate, so the concentrations of the products and reactants are not changing with time. An ampholyte is a substance that has the ability to act as either an acid or a base, depending on the other reactant. Acids are named from the latin acidus meaning sour. Computer calculations of acidbase equilibria in aqueous.
It will also help you to become familiar with conjugated acid. Water can even react with itself to form acids and bases. In particular, the ph of a solution can be predicted when the analytical concentration and p k a values of all acids and bases are known. The equilibrium constant for a strong acid or strong base is undefined, since the reaction the ionization is. Pdf this presentation is useful to familiarize with acidbase equilibria theories. Includes the meaning of the term conjugate as applied to acidbase pairs. Lecture 10 the strong acidstrong base equilibrium calculation. General chemistrychemical equilibriaacidbase equilibrium. Like it or not, sometimes it is just easier to commit really important stuff to memory. Unlike arrhenius acids and bases, they are not limited to aqueous solutions. Can assume other acids you encounter are weak if not one of six above. Entropy, free energy and equilibrium please note that the notes are in powerpoint format. Acids and bases have a chemical equilibrium in solution. This would be easy to know exactly, except that the ha.
Proton transfer in biological systems learning objectives 7. Weak bases partially react to give ions in aqueous solution e. A weak acid equilibrium problem what is the ph of a 0. Although not comprehensive, these few questions do a good job of covering the majority of the concepts and calculations related to this subject area. R p and p r acid dissociation is a reversible reaction. Strong acids, weak acids, strong bases, weak bases acids. Water h 2 o can be both an acid and a base, depending on how you look at it. For all questions referring to solutions, assume that the solvent is water unless otherwise stated. Feb 18, 2014 068 acidbase equilibrium in this video paul andersen explains how acidbase chemistry can be understood in terms of equilibrium. Acids and bases are very common in chemistry and even biology. Relate the strength of an acid to the strength of its conjugate base.
Have a good idea of what are strong acids and bases. Find materials for this course in the pages linked along the left. Strong acidsbases dissociate completely, so their equilibrium constants are overwhelmingly large. Explain the difference between weak and strong acids bases and. Practice identifying acids and bases using bronstedlowry and lewis definitions. Acids and bases react with one another to yield two products.
There are only five possible variables to put into these equations. Acid and base equilibrium ionization of water, kw water is amphiprotic meaning it can act as a base or an acid water is capable of selfionization making itself into ions this can happen in two ways. If stoichiometric amounts are combined, the solution will be slightly basic determine ph of a solution with 0. A bronstedlowry base is defined as a substance that can accept a proton. The strength of bases strong bases completely dissociate into ions in aqueous solution e. Acid and base equilibrium ionization of water, kw water is amphiprotic meaning it can act as a base or an acid water is capable of selfionization making itself into ions. Chemistry 108 chapter 9 lecture notes acids, bases, and equilibrium 3 when an equilibrium constant has a value less than 1, the denominator related to reactant concentration of the equilibrium. The quantitative behaviour of acids and bases in solution can be understood only if their pk a values are known. Practice writing acidbase reactions and identifying acidbaseconjugate acidconjugate base. Strong acids dissociate 100% to ionic form no molecules of acid remain all ions common strong bases know these lioh naoh. Acid proton donor lewis acid nonprotic acids chemists use pka values. Use le chateliers principle to explain how a chemical reaction at equilibrium responds when a change is made to the concentration of reactant or. Acids and bases weak acid and salt of a strong base.