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Acids and Bases

Acids and Bases. By: Karthik Meda, Mehtab Chithiwala, and Ariba Memon. Arrhenius Acid. An Arrhenius acid is a substance that when added to water increases the concentration of H + ions present. When writing an Arrhenius acid solution, the hydrogen ion comes first. .

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Acids and Bases

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  1. Acids and Bases By: Karthik Meda, Mehtab Chithiwala, and Ariba Memon

  2. Arrhenius Acid • An Arrhenius acid is a substance that when added to water increases the concentration of H+ ions present. • When writing an Arrhenius acid solution, the hydrogen ion comes first.

  3. Examples of Arrhenius Acids • HCl is an Arrhenius acid and its equation is: • Other Arrhenius acids: -HBr -HI -HNO3

  4. Arrhenius Base • Arrhenius base is a substance that when added to water increases the concentration of OH- ions present.

  5. Examples of Arrhenius Bases • NaOH is an example of an Arrhenius base and its equation is: • Other Arrhenius bases: -RbOH -Mg(OH)2

  6. Neutralization Reaction • An Arrhenius acid base pair will always undergo a neutralization reaction to make a salt and water.

  7. Bronsted-Lowry Theory • The Bronsted Lowry Theory focuses on the relationship of acids and bases to hydrogen ions, which are also called protons. • Unlike Arrehenius Theory, Bronsted-Lowry Theory can describe: • Reverse reactions for weak acid-base reactions by using conjugate acid-base pairs.

  8. Bronsted-Lowry Acid • Bronsted-Lowry Acid is defined as any substance that can donate one or more hydrogen ions when mixed in a solution. • Bronsted-Lowry Acids are also called Proton Donors.

  9. Bronsted-Lowry Base • Bronsted-Lowry Base is defined as any substance that can accept one or more hydrogen ions when mixed in a soution. • Bronsted-Lowry Bases are also called Proton Acceptors. • This theory also validates substances that are classified as bases even though they do not contain OH ions.

  10. Characteristics of Acids • Acids turn blue litmus paper to red. • Acids taste sour. • Anything lower then 7 on the pH scale are considered acids. • Oranges contain Citric Acid.

  11. Characteristics of Acids • Acids react strongly with metals. • Acids feel like water on your skin. • Can conduct electricity. • Acids react with bases to form salt and water. Vinegar is a type of acetic acid.

  12. Characteristics of Bases • Bases taste bitter. • Bases feel like soap on our skin. • Bases have a pH of 7 or greater. Sodium hypochlorite (NaClO), more commonly known as bleach, is a base that we use everyday.

  13. Characteristics of Bases • Bases don’t react with metals. • Can conduct electricity. • Bases turn red Litmus paper into blue. • Bases react with acids to form salts and water. Toothpaste is a base which we come in contact with everyday.

  14. pH Scale • The pH scale is a scale that ranges from 0-14 and measures the acidity or alkalinity of a substance. • pH of 0 is considered very acidic, pH of 7 is considered neutral, and pH of 14 is considered very basic.

  15. What is the difference between a pH of 4 and a pH of 5? • A pH of 4 is 10 x more acidic than a pH of 5! • A pH of 4 is ____ x more acidic than a pH of 6. • 100 • A pH of 10 is ____ x more acidic than a pH of 13. • 1000 • A pH of 13 is ____ x more basic (alkaline) than a pH of 12. • 10

  16. Can you identify the acid-base pairs? • HF + H2O  H3O+ + F- • A BCA CB • According to Bronsted-Lowry, an acid _____ protons (hydrogens) and bases ____ protons (hydrogens) • Donates (gives away), accept (take)

  17. Calculating pH and pOH • Calculate the pH and pOH of a solution in which [OH-]=6.8 e –5M. • pOH = -log [OH+] • pOH= 4.2 • pH = 9.8 • Is this an acid or a base? • Base because the pH is 9.8

  18. ACID OR A BASE? • pH of 2 • acid • Laundry detergent • base • Donates Hydrogen ions • acid • Tastes sour • acid • Feels slippery • base • Colas • acid • Tomatoes • acid • Bleach • base

  19. Remember to study naming and writing formulas! See the other powerpoints! • NaCl • Sodium chloride • H2SO4 • Sulfuric acid • S3O5 • Trisulfurpentoxide • Dinitrogentetrafluoride • N2F4 • Calcium hydroxide • Ca(OH)2 • Hydrobromic acid • HBr • Nitric acid • HNO3

  20. TEST TOMORROW! • You are not responsible for any slides that come after this.

  21. Acid Rain • Acid rain is combination of wet and dry deposition from the atmosphere that contains higher than normal levels of acidic components. • The acidic components are mainly sulfuric, nitric and carbonic acids, but there are also other chemicals such as ammonia. • Wet depositions are usually in form of rain, snow, and fog. • Dry depositions are usually in form of wind, dust, and smoke.

  22. Causes of Acid RainAcid rain forms when the emissions of acidic gasses react with water and oxygen in the atmosphere to form acidic solutions. • Power plants release majority of the nitrogen oxides and sulfur dioxide by burning fossil fuels such as coal, in order to produce electricity. • Factories and motor vehicles also emit sulfur dioxide, nitrogen oxides and carbon dioxide.

  23. Continued • Livestock also plays a major part by releasing ammonia from the waste they create. Although ammonia is a base it is still a component of acid rain because it combines with sulfer to form ammonium sulfate. • Natural events such as volcano eruptions, forest fires, lightning, and decomposition of plants also release sulfur dioxide and nitrogen oxides.

  24. Effects of Acid Rain • Acid rain induces toxic substances into the soil such as aluminum as well as dissolve nutrients that are essential to the plants. They also deteriorate leaves, thus making plants vulnerable to the natural elements. • Acid rain damages fishes and other aquatic life by harming the organisms’ ability to reproduce and destroying the ecosystems by dissolving essential nutrients and releasing aluminum.

  25. Continued • Acid rain ruins man-made structures and equipments by dissolving marble, sandstone and limestone, corroding metals, textiles, and paint. This not only destroys buildings but erases cultural and historic traces by damaging irreplaceable monuments. • Humans are also affected by acid rain, by developing respiratory problems, such as asthma, due to the sulfur dioxide and nitrogen oxide in the air.

  26. Acid Rain Solution • Alternative sources of energy are a great way to minimize acid rain in the world. Renewable sources such as solar and wind power can eliminate the need to burn fossil fuels (which contributes to 69.4% of the sulfur dioxide emissions). - This also includes use of low emission vehicles such as electric cars that can reduce pollution.

  27. Videos and Comic Our own comic about acid rain. YouTube videos. Note: We have received permission to use these videos.

  28. Annotations • http://facultyfp.salisbury.edu/dfrieck/htdocs/212/rev/acidbase/arrhenius.htm • http://images.google.com/imgres?imgurl=http://www.lakelandschools.us/lh/lburris/images/absolution.gif&imgrefurl=http://www.lakelandschools.us/lh/lburris/pages/acid-base.htm&usg=__WmwyeikGuCbjj-NdwR3FQXkpwAo=&h=275&w=200&sz=26&hl=en&start=8&itbs=1&tbnid=Qutoub1NEISGmM:&tbnh=114&tbnw=83&prev=/images%3Fq%3Darrhenius%2Bacids%26hl%3Den%26sa%3DG%26gbv%3D2%26tbs%3Disch:1 • http://www.vigoschools.net/~mmc3/ana%20lecture/Unit%205%20-%20Acids,%20Bases%20and%20Equilibrium/L4%20-%20Bronsted-Lowry%20Acid%20Definition.pdf • http://www.epa.gov/acidrain/what/index.html • http://www.buzzle.com/articles/causes-and-effects-of-acid-rain.html

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