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Acids and Bases

Acids and Bases. Chapter 23. Common Acids and. Acids. Acids are H+ or proton donors: Properties Acids taste sour (e.g. vinegar, lemon juice). Acids are harmful to living cells. Aqueous solutions of all acids contain hydrogen ions, H+. Water is needed. Common Bases. Base properties.

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Acids and Bases

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  1. Acids and Bases Chapter 23

  2. Common Acids and

  3. Acids • Acids are H+ or proton donors: • Properties • Acids taste sour (e.g. vinegar, lemon juice). • Acids are harmful to living cells. • Aqueous solutions of all acids contain hydrogen ions, H+.

  4. Water is needed

  5. Common Bases

  6. Base properties • Most bases are oxides, hydroxides or carbonates of metals • Soluble bases are known as alkalis. • Aqueous solutions of alkalis contain hydroxide ions, OH-. • Bases taste bitter. . • Bases feel slippery

  7. Base and indicators • Bases turn red litmus blue.A common indicator, used to detect the presence of a base, is phenolphthalein which, when mixed with a base, turns pink. • Bases release hydroxide ions in water solutions.  • NaOH (s)  +  H2O (l)   à   Na1+ (aq)   +   OH1- (aq) • NH4OH  (aq)  ß -> NH41+ (aq)  +  OH1-  (aq)   

  8. pH scale • Water is defined as having a pH value of 7- neutral. • Acidic solutions have pH values below 7. • Alkaline (basic) solutions have pH values above 7. • pH is a measure of the number of hydronium or hydroxide ions • Logrithimic scale

  9. pH scale

  10. Reactions of AcidsWith metals •  Metals above copper in the reactivity series will react with acids, giving off hydrogen gas. The metal dissolves, forming a salt.  •  METAL + ACID  SALT + HYDROGEN • ex. Mg(s) + H2SO4(aq)  MgSO4(aq) + H2(g) • This is why acids corrode metals, and must be stored in glass containers.

  11. With bases (metal oxides and hydroxides)  The base dissolves in the acid and neutralises it. A salt is formed. ACID + BASE  SALT + WATER ex.       H2SO4(aq) + CuO(s)  CuSO4(aq) + H2O(l) With metal carbonates Metal + Base Salt + water + CO2 2HCl(aq) + CaCO3(s)  CaCl2(s) + H2O(l) + CO2(g) Base reactions

  12. Indicators • Indicators- an organic compound that turns color in the presence of an acid or base

  13. Naming Acids • Prefix is always hydro • Name the second element with the suffix -ic • HCl – hydrochloric • HF- Hydrofluoric

  14. For the acid containing the most common polyatomic ion of its group simply use the first part of the polyatomic name and follow with the suffix ic. For the acid containing the polyatomic with one less oxygen than the ic, use the suffix ous. For the acid containing the polyatomic with two less oxygens than the ic, use the prefix hypo and the suffix ous. • For an acid containing the polyatomic with one more oxygen than the ic, use the prefix per and the suffix ic.

  15. Naming Bases and Salts • Follow regular naming rules

  16. Acid Reactions

  17. Molarity • Molarity indicates the concentration • Given in the unit Moles/Liters • Moles is the SI unit for quantity- it indicates 6.022 x1022 atoms or molecules of a substance • It is equal to the atomic weight of the element in grams • Ex. 16.00 g of O is one mole • 32.00 g of O2 one mole

  18. Neutralization • Reactions in which an acid is added to a base cause neutralization • This usually results in a salt and water • IN the case of carbonate bases it results in a carbonate salt, water, and carbon dioxide

  19. Titration • A titration is a process where by the concentration of an unknown acid or base is determined by using a solution with a known concentration. • This solution is known as the standard solution. • The formula M1V1=M2V2 is used to determine the molarity of the unknown

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