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Definition of ACID: Anything that produces hydrogen ions in a water solution. HCl H + + Cl - Proton donor – adds H+ to solvent. Properties of Acids. 1. Tart, sour taste…. 2. Aqueous solutions of acids are electrolytes , meaning they conduct electricity.
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Definition of ACID: Anything that produces hydrogen ions in a water solution.HCl H+ + Cl-Proton donor – adds H+ to solvent
Properties of Acids 1. Tart, sour taste… 2. Aqueous solutions of acids are electrolytes, meaning they conduct electricity Example: vinegar (ethanoic acid or acetic acid ) lemons (citric acid )
More Properties of Acids 3. They cause dyes called indicators to change color…turn blue litmus paper red 5. ACIDS react with BASES to form water and salt…neutralization rxn 4. Metals react with acid solutions to form hydrogen… the acids corrode metals.
Definition of BASE: Anything that produces hydroxide ions in a water solution.NaOH Na+ + OH-Proton acceptor – removes H+ from solvent
Properties of Bases 1. React with acids to form water and salt 2. Taste bitter 3. Feel slippery 4. Can be strong or weak electrolytes 5.Change the colors of an indicator ..turn red litmus to blue Example: milk of magnesia (MgOH)
Common Basesall have OH at the end KOH Potassium Hydroxide NaOH sodium Hydroxide Ca(OH) 2 calcium hydroxide Mg (OH) 2 magnesium hydroxide
Strong or Weak Acids and Bases The strength of an acid or base depends NOT on the amount of H+ ions or OH- ions but on the degree of ionization. What is ionization? It is the process of adding or removing electrons from an atom or molecule, which gives the atom or molecule a net charge.
Neutralization Reaction HCl(aq) + NaOH(aq)→ NaCl(aq) + H2O The reaction of hydronium ions (H+) and hydroxide ions (OH-) to form water molecules.
Monoprotic acids with one H, example: HNO3 nitric acid Diprotic acids with 2 H, example: H2SO4 sulfuric acid Triprotic acids with 3 H, example: H3PO4 phosphoric acid
Rules for Formulas and Naming of Acids *General formula : HaXb , where the “X” could stand for any element or polyatomic ion Formula: Hydrogen + another element Naming: Change the original endings of ions to the following: “ide”-----”ic”, with hydro at the beginning With polyatomics, just change “ite”-to-- “ous” & “ate”-to-”ic”
Formulas and Names of Acids Examples: HClhydrogen chloride becomes HNO3 hydrogen nitrate becomes H2SO3hydrogen sulfite becomes H2CO3hydrogen carbonate becomes HClO3hydrogen chlorate becomes HFhydrogen fluoride becomes
Naming Bases name basesnormally: NaOH = sodium hydroxide Ca(OH) 2 = calcium hydroxide Neutral - being neither acidic nor basic Example: pure water
Salts • Salts are ionic compouns that contain a positive ion that is not H+ and a negative ion that is not OH- • Have high melting points • Good conductors of electric current
Aqueous solutions of Acids • The hydrogen ion in aqueous solution is best known as a hydronium ion: H3O+ • An example of an acid ionizing would be: • HNO3(l) + H2O(l) H3O+(aq) + NO3-(aq)
pH Scale • pH of a solution is defined as the negative of the common logarithm of the hydronium atom concentration (H3O+) • pOH negative of the common logarithm of hydroxide ion concentration (OH-) • pH + pOH = 14
pH and pOH • If pH = -log (1x10-6) pH = 6 We know pH + pOH = 14 So 6 + pOH = 14 pOH= 8
Conjugate Acids and Bases • When an acid gives up a proton (H+) it can re-accept that proton and act as a base this is known as a conjugate base HF(aq) + H2O(l) F-(aq) + H3O+(aq)
In this reaction water is acting as a base and accepting H+; this makes it a conjugate acid because it accepts a proton HF(aq) + H2O(l) F-(aq) + H3O+(aq)
Strength of conjugate acids and bases • HCl is a strong acid • This means it gives up H+ ions easily • Therefore Cl- must be a very weak base • The stronger an acid is the weaker its conjugate base • The stronger the base the weaker the conjugate acid
Titration • A titration is a technique where a solution of known concentration is used to determine the concentration of an unknown solution • Adds an acid to a base or vice versa to reach neutralization
Titration • Equivalence point • Two solutions are present in equivalent amounts • Indicators and pH meters are used to determine equivalence point • Color change happens when neutralization has occurred
Titration • End point • Point in titration where indicators turn color • Molarity is used to determine the unknown concentration