• Chapter 8 – Acids and Bases

     

     

    Electrolyte:

    a substance that dissolves in water and forms a solution that conducts electricity

    conducts electricity due to the presence of ions

    ionic compounds and many polar compounds dissolve in water and conduct electricity

     

    Example:

    Determine the electrolytes that form when the following substances are dissolved in water:

     

    KBr

     

     

     

    HCl

     

     

     

    HBr

     

     

     

    HF

     

    ACIDS

     

    Aqueous solutions of acids conduct electricity (in other words, they are electrolytes)

     

    Acids react with certain metals to produce hydrogen gas

     

    Use Table J In Your Reference Tables To Find Out Which Metals React:

    describes how active each metal and nonmetal is

    the most active metals are near the top of the table

    activity of metals decreases as you go down the table

    metals ABOVE hydrogen (H2) on the table are more active than hydrogen and react with HCl to produce hydrogen gas!!

     

    Ex:

    Ca

    Ca + 2HCl CaCl2 + H2

     

    Acids cause color changes in acid-base indicators:

    Blue Litmus Paper: turns red in an acid

    Phenolphthalein: is colorless in an acid

     

    Acids react with bases to form salt and water

    Neutralization Reaction:

     

    HCl + NaOH -----> NaCl + H2O

    acid   base            salt     water

     

    Acids have a sour taste

     

    Names of acids and formulas are listed in TABLE K!!

     

    BASES

     

    Aqueous solutions of bases conduct electricity (are electrolytes)

     

    Bases cause color changes in acid-base indicators:

    Red Litmus Paper: turns blue in a base

    Phenolphthalein: turns pink in a base

     

    Bases react with acids to form salt and water (see Neutralization Reaction above)

     

    Bases feel slippery

     

    Names of bases and formulas are listed in REFERENCE TABLE L!!

     

     

    ARRHENIUS THEORY OF ACIDS AND BASES

     

    Arrhenius Acids:

    an Arrhenius acid has an “H” AND releases H+ ions as the only type of positive ion in an aqueous solution

     

     

    Examples: HCl, HBr, H2SO4

     

    in aqueous solutions, the H+ (hydrogen ion) is attached to H2O and forms H3O+ (hydronium ion)

     

    Ex:

     

     

    HCl + H2O H3O+ + Cl-

     

    H2SO4 + 2H2O 2H3O+ + SO4-2

     

    H3PO4 + 3H2O 3H3O+ + PO4-3

     

     

     

    Arrhenius Bases:

    an Arrhenius Base has “OH” AND releases OH- (hydroxide ions) as the only type of negative ion in aqueous solutions.

     

    Examples:

     

    NaOH  ------>  Na+ + OH-

     

     

    Ba(OH)2 Ba+2 + 2OH-

     
Last Modified on April 21, 2020