Properties of acids and bases

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Properties of acids and bases

• Sour/tart taste
• Conduct electricity
• Litmus turns red
• Release H into water
• pH lt 7
• Neutralize a base
• Usually start with H
• Most food items

• Slippery to the touch
• Bitter taste
• Conduct electricity
• Litmus turns blue
• Release OH- into water
• Neutralize an acid
• pH gt 7
• Most cleaning items

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An acid is a compound that gives H (or H3O) in
water. Acids generally begin with H. HCl H2O ?
H3O1 Cl-1 HCl ? H1 Cl1 A base is a
compound that gives OH- in water. Bases usually
end in OH. NaOH ? Na1 OH-1 An indicator is a
colored substance that can exist in either an
acid or base solution.
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Two common indicators Litmus paper red ?
blue 6.8 ? 7.3 Phenolphthalein clear ?
pink 8.3 ? 8.4
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Monoprotic acids or bases that give off one
H1(acid) or OH-1(base) HCl ? H1 Cl-1 NaOH ?
Na1 OH-1 Diprotic acids or bases that give
off two H1 (acid) or two OH-1(base) H2SO4 ? 2
H1 SO4-2 Ca(OH)2 ? Ca2 2OH-1 Triprotic
acids or bases that give off three H1(acid) or
three OH-1(base) H3PO4 ? 3H1 PO4-3 Al(OH)3 ?
Al3 3 OH-1 Ions charged particles
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• Naming acids
• Common acids normally begin with H. When you see
  a compound that begins with H, it should be named
  as an acid. The name of the acid depends on the
  negative ion
• If the name of the anion ends in ide
• Hydro (anion without ide) ic acid
• HCl hydrochloric acid
• HBr hydrobromic acid
• H2S hydrosulfuric acid

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• If the anion ends in ate, everything is the same
  except do not add the prefix hydro-
• (anion name without ate) ic acid
• HNO3 nitric acid
• HClO3 chloric acid
• H2SO4 sulfuric acid

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Common acids and bases

• HCl
• HNO3
• H2SO4
• HC2H3O2
• HBr
• H2CO3
• H3PO4

• NaOH
• KOH
• Ca(OH)2
• Mg(OH)2
• Ba(OH)2

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Bronsted Acid-Bases Acid a substance that gives
up H Conjugate Base what is left after the
acid gives up H Base a substance that gains
H Conjugate Acid what is left after the base
gains H Plain acids and bases are on the left
side of a reaction, the conjugate acid and base
are on the right side of a reaction.
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C2H3O2-1 NH41 ? HC2H3O2 NH3 B A
CA CB H2O H3PO4 ? H3O1 H2PO4-1
B A CA CB H2O NH3 ? OH-1 NH41 A B
CB CA HSO4-1 C6H5-1 ? C6H6 SO4-2 A
B CA CB
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concentration (unit of molarity) In pure
water at 25oC H1 1.00 E-7 M OH-1 1.00
E-7 M H1xOH-1 1.00E-7 x 1.00E -7
1.00E-14 One way of expressing the H1 or the
OH-1 is the pH. pH -logH1 pOH
-logOH-1
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Important Formulas pH pOH 14.00 H1 x
OH-1 1.00 E-14 pH -logH1 pOH
-logOH-1 pH Scale 0?6.99 acid 7.00 neutral 7.
01 ? 14.00 base
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• To calculate the pH (or the pOH)
• (-)
• log
• H1 (or OH-1
• To calculate H1 (or OH-1)
• 10x (2nd log)
• (-)
• pH (or pOH)

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Strength of an Acid or Base The strength of an
acid (or base) is a measure of how much they
ionize or break up into ions in water. The more
they ionize, the stronger the acid (or base). The
strength of an acid (or base) is measured by the
Ka or Kb. The larger the Ka (acid) or Kb (base)
the stronger it is. Most acids and bases are
weak. There are 6 strong acids and 4 strong
bases Acids H2SO4, HNO3, HClO4, HCl, HBr,
HI Bases NaOH, KOH, Ca(OH)2, Ba(OH)2 All other
acids and bases are considered weak.
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Neutralization Reactions An acid will react with
a base and neutralize each other. The result when
they are mixed is ALWAYS salt and water. Acid
Base ? Salt Water HA BOH ? BA HOH HCl
NaOH ? NaCl HOH
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• To predict the products of neutralization
  reactions
• Recognize that it is a double replacement
  reaction
• Pair up the new products one will always be HOH
  (or water, H2O)
• You can get the correct charges from H1 or OH-1
• Get the correct formulas by crossing the charges
• Balance the reaction

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• H2SO4 Al(OH)3 ?
• H2SO4 Al(OH)3 ? HOH AlSO4
• (pair up new products)
• H2SO4 Al(OH)3 ? HOH Al2(SO4)3
• (get the correct formulas)
• 3H2SO4 2Al(OH)3 ? 6HOH Al2(SO4)3
• (balance the reaction)

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Titration a solution of a known concentration
is reacted with a known volume of a solution of
unknown concentration. At the endpoint, an
indicator will change colors. At that point,
the H1 OH-1. From this
information, the unknown concentration can be
determined.
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1. Write a balanced reaction
2. Label all numbers
3. Use unit analysis
4. Start with the volume of the compound that you
   know both volume and concentration
5. vol ? moles A ? moles B ? conc B

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27.5 milliliters of H2SO4 is exactly neutralized
by 39.3 milliliters of 0.437 M NaOH. What is the
concentration of the acid? H2SO4 2 NaOH ?
Na2SO4 2 HOH Acid 27.5 ml Base 39.3 ml 0.437
M 0.0393 L NaOH 0.437 mol NaOH 1 mol H2SO4
1 1 L NaOH 2 mol
NaOH 0.0275 L H2SO4 0.312M H2SO4
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There is an alternate way to do titration
calculations that does not involve writing
balanced reactions or unit analysis PLHABTSM M1V
1P1 M2V2P2 M1 conc of acid M2 conc of
base V1 volume of acid V2 volume of base P1
protacticity P2 protacticity
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• Protacticity
• P1 of H1 per molecules
• P2 of OH-1 per molecules
• Read the problem
• Label all of the numbers
• Identify the unknown
• Use M1V1P1 M2V2P2
• Solve for the unknown

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27.5 milliliters of H2SO4 is exactly neutralized
by 39.3 milliliters of 0.437 M NaOH. What is the
concentration of the acid? M1 ? M2 0.437
M V1 27.5 ml V2 39.3 ml P1 2 P2 1 M1
M2V2P2/V1P1 (0.437 x 39.3 x 1)/(27.5 x 2)
0.312 M H2SO4