Chemistry notes chapters 20 and 21 acids and bases. Lewis acidbase theory sometimes called donoracceptor theory is a broad, widely applicable approach to the classification of chemical substances and the analysis of chemical reactions. Bronsteds model introduces the notion of conjugate acidbase pairs. An acid is a species which donates a proton bronstedlowry base b. The ph of the salt depends on the strengths of the original acids and bases. 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. Large numbers are strong acids, small numbers are weak acids a strong acid has a stronger tendency to donate a proton a strong base has a. Bronsted lowry acid, lewis acid, acids in aqueous solution, relationship between kb and ka, muliprotic acids, equilibrium calculations, mass balance, equilibrium relationship, proton condition, weak acidbase calculations, strong acidbase calculations, strong acidstrong base mixtures, strong acidweak base mixtures. The caffeine in her coffee is a base, and like all bases, it tastes bitter.
Acids and bases read the passage and study the diagram. Chapter 15 acids and bases some powerpoint lecture slides in this set were prepared by roy kennedy massachusetts bay community college wellesley hills, ma 2008, prentice hall chemistry. 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. Aside from the section on ph which presumes an elementary knowledge of logarithms, there is no math here. A base is a substance that produces hydroxide ions, oh,in water.
The reverse reaction also is the reaction of an acid and a base. For example, acetic acid hc 2 h 3 o 2 is a weak acid. Dr mike lyons school of chemistry trinity college dublin. Ammonia, nh 3, is a weak electrolyte and weak base. Read this article to get information about nucleic acids, its structure, size, types and significance. Given the acid form or the base form of a conjugate pair, identify its. If someone in the family is suffering from a problem of acidity after. Ch 9 acids and bases 116 9 acids and bases the chemistry of acids and bases has remained the core of chemistry from ancient times to the modern era, and indeed, most of chemistry that was performed in laboratories in olden times was the acidbase chemistry. Nivaldo tro 1 stomach acid the cells that line our stomach produce hydrochloric acid, hcl aq to kill unwanted bacteria to help.
By the end of lecture you will be able to calculate the ph of such a solution. Calculating ph of weak bases weak bases are only partially ionized in solution while strong bases are completely ionized, so need to determine the hydroxide concentration via equilibrium, then calculate the poh and then. Ther e are some substances whose odour changes in acidic or basic media. The substance in which the solute dissolves is called the solvent. Notes on acid base chemistry pdf 28p this note contains the following subtopics of acidbase chemistry, bronstedlowry and lewis acidsbases acid dissociation constants, pka, the relative strength of acids and bases, equilibrium in acidbase reactions and molecular structure and acidity. When dissolved in water these various salts do not necessarily give neutral solutions. The reaction between an acid and a base is called neutralization. You missed some questions, but you can learn to identify the strong and weak acids and bases. It is logical that if something an acid exists and may lose a proton, then the product. While boyle and others tried to explain why acids and bases behave the way they do, the first reasonable definition of acids and bases would not be proposed until 200 years later. Water when it self ionizes forms a hydrogen ion acid and a hydroxide ion base. Quizlet flashcards, activities and games help you improve your grades. Acid base chemistry the university of texas at austin.
Similarly, a weak base a base that is less than 100% ionized in aqueous solution. Bases feel slippery, change litmus blue, and become less basic when mixed with acids. The future of the past pdf 9 aqueous acids and bases titration pdf 14 ch 15 modern chemistry textbook questions pdf 10 weak acid, pka pdf 15 textbook questions pdf. On this basis a list of hard and soft acids and bases may be obtained. Strong and weak acids and bases the strength of acids and bases depends on their ability to dissociate or break into their ions in water. Acids and bases are compounds that people use every day. When given only the chemical formula and asked to identify the compound as either an acid or a. Relate the strength of an acid to the strength of its conjugate base.
An acid and base are not two totally separate chemicals but are related. On the other hand, the phenolate anion is already charged, and the canonical contributors act to disperse the charge, resulting in a substantial stabilization of this species. Free acid base chemistry books download ebooks online. All acids contain hydrogen, but not all hydrogencontaining compounds are acids e. Acids, bases and salts chapter2 you have learnt in your previous classes that the sour and bitter tastes of food are due to acids and bases, respectively, present in them.
When we think of acids and bases we tend to think of chemistry lab acids and bases like but we are surrounded by acids and bases in the world. Lesson summary students predict if common household products are acids or bases. The rate of reaction, desired product, yield, handling easiness. Using a computer, bring up the powerpoint file basic chemistry part 2 iii.
The neutralization reaction between an acid and a base produces a salt and water. One of the most common characteristics of acids is their sour taste. Explore the chemistry of acids and bases to see how fundamental they are to the functioning of our world. The negative ions in an acid combine with the positive ions in a base to produce an ionic compound called a salt. Acid ionization reaction in water conjugate base ka kb h. Abuffer is a solution that is resistant to large changes in ph. Buffers can be prepared by mixing a weak acid and its salt or a weak base and its salt. Hcl, hbr, hi, hno 3, hclo 4, h 2 so 4 the following are some less common acids that are also strong. Amphoteric substances are substances which can act as both an acid and a base.
Strong bases dissociate almost completely in water. This classification is shown in the tables below for ligands and metal ions. Lemons and grapefruits taste sour because they contain acids such as citric and ascorbic acid vitamin c. The strong acidstrong base equilibrium calculation after an entire lecture on water with nothing added, you must be pumped to know that in this lecture something will actually be added to watera strong acid or a strong base. While these definitions dont contradict each other, they do vary in how inclusive they are. Hclo 3, hbro 3, hio 3, h 2 seo 4 assume all other acids are weak unless told otherwise.
See how it is done in this little demonstration press play. In any acid base reaction, a conjugate acid and a base pair are established. These are important organic substances found in nucleus and cytoplasm. Hsab theory lewis acids and bases hard and soft acidbase theory definitions of lewis acid base theory. Perhaps the single h20 molecule should decrease in size to reveal others around it. Then theyll learn about the ph scale, acid rain, and human cells. They control the important biosynthetic activities of the cell and carry hereditary information from generation to generation. Lecture 10 the strong acidstrong base equilibrium calculation. If you encounter a molecule that isnt a strong acid or base, all you have to do is determine whether its an acid or a base you already know its weak. The use of simplifying assumptions is even more important for this system. Free acid base chemistry books download ebooks online textbooks. Examples of arrhenius acids are hydrochloric acid hcl, sulfuric acid h 2so 4, and phosphoric acid h 3po 4.
Some acids can eat away metal, some can cause serious skin burns, and others are harmless. These definitions are quite general and refer to the reaction between an acid and a base. Chapter 15 acids and bases bridgewater state university. The key is to learn the short lists of strong acids and strong bases. The baking soda contains a base that neutralizes some of her excess stomach acid. The acid and base that react in the reverse reaction are identified under the equation as a conjugate acid and a. Amphoteric compounds chem 0012 lecture notes 17 acids, bases and salts hebden unit 4 page 109. In that course which probably seems juvenile now, you learned that acids dissociate in. Acidity and basicity, proton concentration, the ph scale, and buffers. Thus, nucleic acids are macromolecules of the utmost biological importance. Pearson chapter 11 acids, bases, and solutions unit test. Weak acids and bases do not dissociate completely, so while the approach to solving the equations is similar to strongacid systems, the complication of the ka is added. By studying various equilibria reactions, qualitative classification of hard and soft acid bases may be established. Hsab theory lewis acids and bases hard and soft acidbase theory definitions of lewis acidbase theory.
Acids and bases touch upon virtually all areas of chemistry, biochemistry, and physiology. Examples of arrhenius bases are sodium hydroxide naoh, calcium hydroxide caoh 2. The kb is the reaction in which a base accepts a proton from a water molecule. Strong acids and bases are strong electrolytes because they dissociate. Acids are classified by the number of hydrogen ions available to be donated. Students will see how these two classes of compounds combine to produce salts. Bronsteds acids and bases are by and large the same acids and bases as in the arrhenius model but the model of bronsted and lowry is not restricted to aqueous solutions. Lewis acidbase theory sometimes called donoracceptor theory is a broad, widely applicable approach to the classification of chemical substances and the analysis of. Acids and bases are important substances in health, industry, and the environment. Know the definitions of bronstedlowry acids and bases. Substances can dissolve in water in three waysby dissociation, dispersion, and ionization. The most common definitions of acids and bases are arrhenius acids and bases, bronstedlowry acids and bases, and lewis acids and bases. The conjugate bases of simple alcohols are not stabilized by charge delocalization, so the acidity of these compounds is similar to that of water.
Acid base chemistry notes pdf 10p this note covers the following topics. As a general rule for weak acids and bases, negative ions in solution will behave as bases. Examples of arrhenius bases are sodium hydroxide naoh, calcium hydroxide caoh 2, and aluminum hydroxide aloh 3. Describe the difference between strong and weak acids and bases. In studying acids and bases we are going to see that water can also participate in chemical reactions 2. Lewis acids and bases hard and soft acidbase theory. Define and identify bronstedlowry acids and bases, and identify conjugate acidbase pairs.
We can rank the strengths of acids by the extent to which they ionize in aqueous solution. Identification of strong and weak acids and bases and. Most metal hydroxides are strong electrolytes and strong bases. Chem1 general chemistry reference text 3 introduction to acidbase chemistry 3 neutralization just as an acid is a substance that liberates hydrogen ions into solution, a base yields hydroxide ions. Chapter 5 acids, bases, and acid base reactions 53 objectives are especially important because they pertain to skills that you will need while studying other chapters of this text. This set of lessons will get you started by presenting the underlying concepts in a systematic way. Pass out the handout acids, bases, and the ph scale. The value of ka or kb is the strength of the acid or base. Chemistry 12 notes on unit 4 acids, bases and salts chemistry 12unit 4notes page 1 chemistry 12 notes on unit 4 part 1 acid base hydronium ions and how they are formed first of all, we must apoligize again for something about chemistry 11.
Amphiprotic substance a substance that can act either as a pppproton acceptor or a proton donor. Nov 07, 2009 can you name the strong acids and bases. In chemistry, and particularly biochemistry, water is the most common solvent 1. A strong acid or strong base completely dissociates e. Ch 9 acids and bases 116 9 acids and bases the chemistry of acids and bases has remained the core of chemistry from ancient times to the modern era, and indeed, most of chemistry that was performed in laboratories in olden times was the.
It changes its colour depending on whether the solution it is in, is basicalkaline or acidic. Using this theory, you should be able to write weak acidbase dissociation equations and identify. Carry out equilibrium calculations for weak acidbase systems. Test your knowledge on this science quiz to see how you do and compare your score to others. These indicators tell us whether a substance is acidic or basic by change in colour. Liquids all around us have either acidic or basic alkaline properties.
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