41. Acids, Bases, Cabbage And some chemicals are in between acids and bases and are called neutral.Red cabbage juice has an interesting property, it changes colors depend if it is http://www.doscience.com/act_archive/home_activities/cabbage_juice/cabbage_juice

To g et a Do Science logo product, click here Send a t-shirt with an activity on the back (Condiment Diver activity is on back). Return to The Archive List Do you have a comment or response to this activity, submit it to the Do Science bulletin board More science activities can be found here: Great for Science Fair projects! While You're Waiting for the Food to Come by Eric Muller, Illustrated by Eldon Doty Hardcover version Paperback version To order or find out more about this book, click on the book cover above or on either cover version. Go to the Do Science Store What's the solution? Acid, base or neutral. Ingredients: Red Cabbage -Some water -Baking-soda -Vinegar -Strainer -Two white or clear bowls -Mixing variations A blender or a sauce pan and stove The Recipe: 1) Chop-up a handful of cabbage.

42. Identifying Acids And Bases Being able to readily identify a species with regards to a acid/base behavior isa very useful skill. This page provides basic drill and practice in this http://chemistry2.csudh.edu/newlechelp/acidorbase.html

Identifying acid-base species Being able to readily identify a species with regards to a acid/base behavior is a very useful skill. This page provides basic drill and practice in this area. Though most of the species should be easily recognized, feel free to use whatever reference materials you wish. Ultimately the goal is to be able to run through the drills without the need of such aids. When you press "New Species", a formula will appear to the right of the table. Click on the appropriate bubble. If the species is weak, to verify that you have properly identified it and are not merely guessing, you will be asked to input the coefficient of the K. Just enter the coefficient. That is, if the K=3.4*10 , just enter the 3.4. You can skip this step and just ask for a new species, if you wish. Since the goal of this page is accuracy, you only get one attempt. If you misidentify the species, the answer will appear. Results Total Done Total Correct

43. Solutions Of Acids And Bases This page randomly generates problems involving acids and bases. In order to usethe page, you need a table of acid/base Ks. To start,press New Problem http://chemistry2.csudh.edu/newlechelp/acidbasecompletevalues.html

Solutions of acids and bases This page randomly generates problems involving acids and bases. In order to use the page, you need a table of acid/base Ks. To start,press "New Problem" and a question will appear to the right of the button. If the acid/base species listed is not in your table, press "New Problem " again. Otherwise, determine the value of the answer, enter it in the cell and press "Check Answer". This page assumes that you can perform the basic calculations on acid/base solutions and its may aim is to demonstrate fully the other aspects, such as percent ionization of such solutions. If you are still having difficulty calculating [H ] for acetic acid solutions, you should return to the pages that only perform that provide that type of problem. Results appear in the table. To begin-press "New Problem" and a question will appear to the right of the button. Put the correct value into the answer cell and press "Check Answer." If you use scientific notation enter the number is the form 2.3e5. The results on the problem and a running total will appear in the second table.

44. Acid Base Definitions In 1887, Arrhenius extended this his idea by defining acids and bases as the Though the Arrhenius theory helped to explain more about acids and bases, http://www.chem.tamu.edu/class/majors/tutorialnotefiles/acidbasedef.htm

Acids and Bases : Development of Acids and Bases 1661 - Robert Boyle Characterized acids and alkalies bases ) as the following: Acids: Sour taste Corrosive Change litmus (dye extracted from lichens) from blue to red Become less acidic when combined with alkalies. Alkalies (Bases): Feel slippery Change litmus from red to blue Become less alkaline when combined with acids. Antoine Lavoisier Believed that all acids contained oxygen after studying several acids e.g. H SO - sulfuric acid, HNO - nitric acid 1811 - Humphry Davy Questioned Lavoisier's theory, noting that hydrochloric acid (HCl) did not contain oxygen yet is an acid. Soon thereafter, several more acids without oxygen were found. e.g. HBr, HF, HI 1838 - Justig Liebig Suggested that acids contain one or more hydrogen atoms which can be replaced by metal atoms to produce salts. e.g. HSCN is an acid because the H atom can be replace by a metal to form a salt, such as NaSCN. 1884-1887 - Svante Arrhenius In 1884, Arrhenius proposed that salts dissociate when they dissolve in water to give charged particles which he called

45. Learn.co.za : Chemistry Solutions of acids and bases cause a colour change of indicators. Solutions ofacids or bases conduct electricity due to the presence of free ions. http://www.learn.co.za/content/grade12/Science/chem_acidsbases/bass/Unit1/

You are here: Classroom Grade 12 Science Chemistry : Acids and Bases ... Acids and Bases : 1. Characteristics of Acids and Bases Other units in this lesson: 2. Acid/Base models 3. Conjugate Acid/Base pairs 4. Acid/Base terminology 5. pH scale and calculations ... 9. Hydrolysis Characteristics of acids and bases Note: Solutions of acids and bases cause a colour change of indicators. Acids and bases react to neutralise each other. Points to remember ! Solutions of acids or bases conduct electricity due to the presence of free ions. Acids taste sour and are clear. Bases feel soapy and are cloudy. Other units in this lesson: 2. Acid/Base models 3. Conjugate Acid/Base pairs 4. Acid/Base terminology 5. pH scale and calculations ... 9. Hydrolysis

46. Acids And Bases: Conjugate Acids And Bases Where a compound is an acid or base is not controlled solely by molecular structure,but rather by the molecule s role in the reaction. Exercises http://web.chem.ucla.edu/~harding/tutorials/acids_and_bases/conj_acids.html

Acids and Bases: Conjugate Acids and Bases Discussion : Proton transfers are key features of many organic and biochemical reactions. If a reactant accepts a proton (a Bronsted-Lowry base ) the product is termed the conjugate acid of that base. An electron pair from the Bronsted-Lowry base is shared with the proton to make a new bond. If a reactant donates a proton (a Bronsted-Lowry acid ), the product is the conjugate base of that acid. The electron pair that was the bond to the transferred proton is left behind as part of the conjugate base. As a fundamental skill necessary to master proton transfer reactions, you will need to be able to draw the conjugates of an acid or base. Example 1 : Provide the products of the following proton transfer reaction. The proton that is transferred is circled. Label all reactants and products as Bronsted-Lowry or conjugate acids and bases. Solution 1 Example 2 : A small portion of the molecules in liquid water have reacted by proton transfer. This process is termed auto-ionization. Write an equation for the auto-ionization of water that clearly illustrates this proton transfer. Name all the products. Label all reactants and products as Bronsted-Lowry or conjugate acids and bases. Solution 2 Note that some compounds such as water in this example can function as either an acid or base. Such compounds are termed amphoteric. Where a compound is an acid or base is not controlled solely by molecular structure, but rather by the molecule's role in the reaction.

47. Organic Acids And Bases Menu Understanding Chemistry. ORGANIC acids AND bases MENU. Organic acids . . .Explains why organic acids are acidic, and what affects their strengths. http://www.chemguide.co.uk/basicorg/acidmenu.html

Understanding Chemistry ORGANIC ACIDS AND BASES MENU Organic acids . . . Explains why organic acids are acidic, and what affects their strengths. Organic bases . . . Explains why primary amines are basic, and what affects their strengths. Go to menu of basic organic chemistry. . . Go to Main Menu . . .

48. Theories Of Acids And Bases Describes the Arrhenius, BronstedLowry, and Lewis theories of acids and bases,and explains the relationships between them. http://www.chemguide.co.uk/physical/acidbaseeqia/theories.html

THEORIES OF ACIDS AND BASES This page describes the Arrhenius, Bronsted-Lowry, and Lewis theories of acids and bases, and explains the relationships between them. It also explains the concept of a conjugate pair - an acid and its conjugate base, or a base and its conjugate acid. Note: Current UK A' level syllabuses concentrate on the Bronsted-Lowry theory, but you should also be aware of Lewis acids and bases. The Arrhenius theory is of historical interest only, and you are unlikely to need it unless you are doing some work on the development of ideas in chemistry. The Arrhenius Theory of acids and bases The theory Acids are substances which produce hydrogen ions in solution. Bases are substances which produce hydroxide ions in solution. Neutralisation happens because hydrogen ions and hydroxide ions react to produce water. Limitations of the theory Hydrochloric acid is neutralised by both sodium hydroxide solution and ammonia solution. In both cases, you get a colourless solution which you can crystallise to get a white salt - either sodium chloride or ammonium chloride. These are clearly very similar reactions. The full equations are:

49. SparkNotes: Introduction To Acids And Bases: Introduction acids and bases play a central role in chemistry because, Finally, Lewis gaveus the more general definition of acids and bases that we use today. http://www.sparknotes.com/chemistry/acidsbases/intro/summary.html

saveBookmark("", "", ""); Home Chemistry Study Guides Intro : Introduction - Navigate Here - Introduction Terms Introduction Acids and bases play a central role in chemistry because, with the exception of redox reactions, every chemical reaction can be classified as an acid- base reaction. Our understanding of chemical reactions as acid-base interactions comes from the wide acceptance of the Lewis definition of acids and bases, which supplanted both the earlier Bronsted-Lowry concept and the first definitionthe Arrhenius model. Arrhenius first defined acids as proton (H ) producers in aqueous solution and bases as hydroxide (OH ) producers. Although this model is intuitively correct, it is limited to substances that include proton and hydroxide groups. Bronsted and Lowry proposed the more general definitions of acids and bases as proton donors and acceptors, respectively. Unlike the Arrhenius conception, the Bronsted-Lowry model accounts for acids in solvents other than water, where the proton transfers do not necessarily involve hydroxide ions . But the Bronsted-Lowry model fails to explain the observation that metal ions make water more acidic (discussed in Calculating pH's ). Finally, Lewis gave us the more general definition of acids and bases that we use today. According to Lewis, acids are electron pair acceptors and bases are electron pair donors. Any chemical reaction that can be represented as a simple exchange of valence electron pairs to break and form bonds is therefore an acid-base reaction.

50. SparkNotes: SAT II Biology: Acids And Bases Like acids, bases can be strong or weak depending on how many hydroxide Some substances resist changes in pH even when acids or bases are added to them. http://www.sparknotes.com/testprep/books/sat2/biology/chapter5section3.rhtml

saveBookmark("", "", ""); Jump to a New Chapter Introduction to the SAT II Introduction to the SAT II Biology Strategies for Taking the SAT II Biology The Cell Organic and Biochemistry Cell Processes Mendelian and Molecular Genetics Evolution and Diversity Organismal Biology Ecology Glossary Practice Tests Are Your Best Friends < return to the previous section continue to the next section >> The Building Blocks of Matter Chemical Bonds ... Explanations Acids and Bases Sometimes atoms give their electrons up altogether instead of sharing them in a chemical bond. This process is known as disassociation. Water, for instance, dissociates by the following formula: H O H + OH The hydrogen atom gives up a negatively charged electron, gaining a positive charge, and the OH compound gains a negatively charged electron, taking on a negative charge. The H is known as a hydrogen ion and OH ion is known as a hydroxide ion The disassociation of water produces equal amounts of hydrogen and hydroxide ions. However, the disassociation of some compounds produces solutions with high proportions of either hydrogen or hydroxide ions. Solutions high in hydrogen ions are known as acids , while solutions high in hydroxide ions are known as bases . Both types of solution are extremely reactive—likely to form bonds—because they contain so many charged particles. The technical definition of an acid is that it is a hydrogen ion donor, or a proton donor, as hydrogen ions are consist of only a single proton. Acids put

51. Household Acids And Bases Household acids and bases Veasley, Joyce Nansen Elementary 38 Pheasant Road The learners will be able to infer the presence of acids or bases from http://www.iit.edu/~smile/ch8812.html

Household Acids and Bases Veasley, Joyce Nansen Elementary 38 Pheasant Road 821-2785 Matteson, Illinois 60443 720-2150 Objectives: 1. The learners will be able to determine whether a substance dissolved in water will form an acid, a base or a neutral solution. 2. The learners will be able to infer the presence of acids or bases from evidence in the demonstration of interactions of common household products and an indicator. Apparatus Needed: 1. Egg Cartons (one for every two students) 2. Litmus Paper (red and blue) 3. 10 Household solutions: a. lemon juice b. bleach-water c. water d. aspirin-water e. milk f. ammonia-water g. tea (concentrated) h. vinegar-water i. soap-water j. your saliva 4. 10 Eye Droppers 5. 10 Small Containers, or Clear Cups 6. Red Cabbage 7. 100 mL Water 8. 8 Test Tubes 9. Tube 1. 10 mL of Lemon Juice 10. Tube 2. 10 mL of White Vinegar 11. Tube 3. 10 mL of Boric Acid Solution 12. Tube 4. 10 mL of Water 13. Tube 5. 10 mL of Sodium Bicarbonate Solution 14. Tube 6. 10 mL of Borax Solution 15. Tube 7. 10 mL of Washing Soda Solution 16. Tube 8. 10 mL of Drain Cleaner 17. Test Tube Holder 18. Beakers, 100 and 250 mL 19. Burner Recommended Strategy: Return to Chemistry Index

52. Acids/Bases Introduction Students will define bases and acids and how they are significantin our They will be asked how much they know about acids and bases. http://www.iit.edu/~smile/cb1398.htm

Biology /Chemistry Acids/Bases Chandra E. Price Burnham/Anthony Inclusive 10516 S. Wood St. 1903 East 96 Street Chicago IL 60643 Chicago IL 60617 Objective(s) The student will be able to: 1) distinguish between the differences of acids/bases, 2) demonstrate how to test for acids and bases, and 3) communicate the significance of testing for acids and bases. Materials Needed Detergent-quart, shampoo- quart Lemon-juice-quart Milk-quart Orange-juice-quart Tomato-juice-quart Baking-soda Salt-shaker Peroxide-quart Red-cabbage-small Apple-juice Containers-plastic-25 Hot plate distilled water Paper towels eye droppers station signs Pepto Bismol acid rain paper towels Markers spoons antacid tablets Pickle juice large containers transparent containers Safety glasses pot holders aprons Vocabulary Acid, base, chemistry, indicator Strategies Strategy 1 Introduction: What you Know, What you will Learn What you have learned.). Strategy 2 Dramatization: Traditional vs. Phenomenological Ms. Traditional asked her students to read and answer questions about acids and bases. She gave little explanation and no hands on activities for the students to become involved. When she went over the assignment the majority of the class did not complete the assignment. However, in Ms. Phenomenological the atmosphere was different. She began eating an orange and indicated that her mouth was burning. She asked the students what they thought her problem was? Someone responded, "there might be too much acid in that orange". What a great statement! Then, she states, "we are going to learn about acids and bases."

53. Acids And Bases. The Columbia Encyclopedia, Sixth Edition. 2001-05 acids and bases. The Columbia Encyclopedia, Sixth Edition. 200105. http://www.bartleby.com/65/ac/acidsNba.html

Select Search All Bartleby.com All Reference Columbia Encyclopedia World History Encyclopedia Cultural Literacy World Factbook Columbia Gazetteer American Heritage Coll. Dictionary Roget's Thesauri Roget's II: Thesaurus Roget's Int'l Thesaurus Quotations Bartlett's Quotations Columbia Quotations Simpson's Quotations Respectfully Quoted English Usage Modern Usage American English Fowler's King's English Strunk's Style Mencken's Language Cambridge History The King James Bible Oxford Shakespeare Gray's Anatomy Farmer's Cookbook Post's Etiquette Bulfinch's Mythology Frazer's Golden Bough All Verse Anthologies Dickinson, E. Eliot, T.S. Frost, R. Hopkins, G.M. Keats, J. Lawrence, D.H. Masters, E.L. Sandburg, C. Sassoon, S. Whitman, W. Wordsworth, W. Yeats, W.B. All Nonfiction Harvard Classics American Essays Einstein's Relativity Grant, U.S. Roosevelt, T. Wells's History Presidential Inaugurals All Fiction Shelf of Fiction Ghost Stories Short Stories Shaw, G.B. Stein, G. Stevenson, R.L. Wells, H.G. Reference Columbia Encyclopedia PREVIOUS NEXT ... BIBLIOGRAPHIC RECORD The Columbia Encyclopedia, Sixth Edition. acids and bases two related classes of chemicals; the members of each class have a number of common properties when dissolved in a solvent, usually water.

54. Foundations To Chemistry - Adapted From "Chemistry, Matter And The Universe" acids and bases, Previous Page Next Page. Introduction. acids are familiar to usbecause of their power as corrosive agents and solvents, bringing into http://www.chem.ox.ac.uk/vrchemistry/chapter16/pag01.htm

16. Ions and Equilibrium; Acids and Bases Introduction Acids are familiar to us because of their power as corrosive agents and solvents, bringing into solution compounds that are insoluble in water alone Strong acids will attack many metals, converting them to soluble ions and liberating bubbles of hydrogen gas in the process. Acids also will dissolve carbonates such as limestone, and certain other minerals and inorganic compounds. The weaker acids that are safe to taste, such as citric acid in lemons and acetic acid in vinegar, have a characteristic mouth puckering sharp taste that we immediately recognize and designate as "acid". Bases also are useful for dissolving water-insoluble substances, especially oils, greases, and other organic compounds. Sodium hydroxide, for example, will attack the oils of the skin and turn them into soap, which is why solutions of household lye feel slippery to the touch. We have seen previously that there are many substances, amphoteric oxides among them, that are insoluble in plain water but are dissolved either by an acid or a base, or both.

55. Introduction To Acids And Bases Arrhenius Concept Of Acids And Bases Bronsted Lewis Concept of acids and bases ..Arrhenius Concept of acids and bases ..Equilibriumwith acids and bases ..BronstedLowery Concept of acids and bases. http://www.cartage.org.lb/en/themes/Sciences/Chemistry/Inorganicchemistry/AcidsB

Themes Science Chemistry Inorganic Chemistry Themes Science Chemistry Inorganic Chemistry ... Bronsted-Lowery Concept of Acids and Bases

56. Acids And Bases The Operational Definition Of Acids And Bases Typical Acids And Themes Science Chemistry Inorganic Chemistry acids and bases ..acids andbases ..pH As A Measure of the Concentration. http://www.cartage.org.lb/en/themes/Sciences/Chemistry/Inorganicchemistry/AcidsB

Themes Science Chemistry Inorganic Chemistry Themes Science Chemistry Inorganic Chemistry ... Strong and Weak Acids and Bases

57. Acids And Bases You may wish to take the Quiz on acids and bases to test your understanding ofthe material. Instructor Use of CheModules http://www.karentimberlake.com/acids_and_bases.htm

C heModule T utorials Chapter 9 The following tutorials are PowerPoint Chemodules that emphasize various topics in Acids and Bases. Each includes basic concepts and learning checks to test your progress. Acids and Bases Acids, Bases and Neutralization pH Strong and Weak Acids Downloading CheModules The CheModules may take 2-3 minutes to download. Within the PowerPoint module, use the forward, back, up and down arrows on your keyboard to move down the slide or to go forwards or back up. You may also use page up and page down. P owerPoint© Viewer I f you do not have PowerPoint© on your computer, you may download one of the following powerpoint viewers: http://office.microsoft.com/downloads Search for Powerpoint Viewer or go to PowerPoint Viewer 97 (2000 Release) for PowerPoint 2000 Users PowerPoint Viewer 97 (2000 Release) for PowerPoint 97 Users Learning with CheModules As you proceed in the module, study the slides. Work the short learning checks before you go to the next slide, which contains the correct answers. You may wish to take the Quiz on Acids and Bases to test your understanding of the material.

58. PH - Acids And Bases Strong acids and bases are hazardous to skin and eyes and can cause serious burns . The indicators used to identify acids and bases, are large organic http://ep.llnl.gov/bep/science/9/tPh.html

pH - Acids and Bases Advance Preparation pH paper is not pre-cut, so it will take at least 5 minutes to cut enough pH paper for one class. It should take ten minutes to assemble the other materials. Introduction Acids and bases are common, everyday substances.: Baking soda, sodium hydrogen carbonate (NaHCO3) is a weak base. Soda-pop, carbonic acid (H2CO3) is a weak acid. Stomach acid (HCl) hydrochloric acid is a relatively strong acid. Ammonium hydroxide (NH4OH) has a strong odor, but is not a strong base. Strong acids and bases are hazardous to skin and eyes and can cause serious burns. Sulfuric acid (H2SO4) is a strong acid. Sodium Hydroxide (NaOH) is a strong base. (See overhead) The indicators used to identify acids and bases, are large organic molecules that change color in acid or base. The most common acid/base indicator is litmus paper which changes color in the presence of any acid or base. Other indicators are specific and will change color only at a particular pH (H+ ion concentration). Once you have determined if a substance is an acid or a base, you need to determine how strong (or concentrated) it is. The simplest measure of the strength of an acid or base is the concentration of H+ ion in the solution. The fastest way to determine pH is to use pH paper. It uses a broad range indicator to turns a series of colors from pH 1 to 14. The color change is then compared with a color chart to determine the pH. A high pH indicates a base, and a low pH indicates an acid. A pH near 7 indicates a neutral substance. Students should be aware that shampoos and soaps and most skin products are pH balanced near 7, to protect skin, hair and eyes.

59. Montshire Museum: Acids And Bases There s some pretty interesting chemistry involved with acids and bases, too.acids and bases can neutralize each other when combined, acids lose their http://www.montshire.org/minute/mm990823.html

Montshire Minute: Acids and Bases Originally aired during the week of August 23, 1999 Monday O.K. Mr. Science person, today we're going to test liquids for acididity. Your first job is to stick this juicy slice of lemon in your mouth. Then, wash your mouth out with soap. Not interested? Well, in the past scientists have used taste as one way to distinguish acids from bases. The English chemist Robert Boyle established the following "taste criteria" for acids and bases: Acids taste sour and bases or "alkalies" (like those found in soap) feel slippery on the tongue. The name "acid" comes from the Latin word acidus meaning "sour." Citric acid is what makes lemons tart and sour. Alkalies in soap are more commonly known as bases because they are the "base" for making certain salts. There's some pretty interesting chemistry involved with acids and bases, too. Acids and bases can neutralize each other: when combined, acids lose their acidity and bases become less "alkaline" or basic. Tuesday Some neutralization reactions are just delicious. Don't believe me? As Tina Seelig writes in The Epicurean Laboratory, cooks are really doing acid-base chemistry when they bake. Let's say you're whipping up a batch of pancakes for breakfast. When you mix an acidic ingredient like buttermilk with a basic ingredient like baking soda, a neutralization occurs, producing carbon dioxide, gas, and water. The carbon dioxide bubbles expand when the batter is poured on a hot griddle, making the batter rise. Leavening agents like baking soda get most of the credit for making pancakes rise, but you actually need an acidic ingredient like buttermilk, yogurt, or even honey to make the carbon dioxide bubbles. In recipes that lack acidic ingredients, baking powder is used rather than baking soda. Baking powder is baking soda with a acid-like cream of tartar-already built in.

60. Acids And Bases acids and bases are encountered frequently both in chemistry and in everyday acids and bases are carefully regulated in the body by the lungs, blood, http://www.elmhurst.edu/~chm/vchembook/180acidsbases.html

Acids and Bases Elmhurst College Acids Acid-Base Strength ... Virtual ChemBook Acids and Bases Introduction and Definitions: Acids and bases are encountered frequently both in chemistry and in everyday living. They have opposite properties and have the ability to cancel or neutralize each other. Acids and bases are carefully regulated in the body by the lungs, blood, and kidneys through equilibrium processes. What are acids and bases? Observational definitions: Acids: Bases: Taste sour. Taste bitter. Give sharp stinging pain in a cut or wound. Feels slippery Turn blue litmus paper red. Turn red litmus paper blue. Turn phenolphthalein colorless. Turn phenolphthalein pink. React with metals to produce hydrogen gas. React with carbonates or bicarbonates to produce carbon dioxide gas. See the graphic on the left as a base is wiped over the paper which already has the indicator phenolphthalein on it. The drawing changes to pink. What are Acids and Bases - on a molecular level?

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