Strengths of Acids Arrhenius

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Strengths of AcidsArrhenius Bronsted-Lowry
definitiongives H, hydronium ions in solution

• Strong acids break down 100 in solution
• HCl hydrochloric acid
• HNO3 nitric acid
• HBr hydrobromic acid

• Weak acids do NOT break down completely

H2S
More break down stronger acid
HCl
Cl-
H
H
H
S-2
H
Cl-
Cl-
H2S
Cl-
H2S
H
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Strong vs Weak

• Strong will light a bulb brightly!

• Weak will make the bulb light dimly.

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Strong BasesArrhenius definition donates
OH-Bronsted-Lowry definition accepts
HStrength is determined the same way as
acidsMore break down stronger base

• Strong bases break down 100 in solution
• KOH
• Ba(OH)2
• CsOH
• NaOH

• Weak bases do not break down completely
• Ca(OH)2
• LiOH
• RbOH

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pH Scale
Battery Acid HF
Stomach acid, HCL
Lemon juice, vinegar

• pH power of hydrogen
• pH -log H
• Each time you change a number on the scale you
  change by a factor of 10
• pH of 3 is 10 times less acidic as pH of 2
• pH of 1 is 100 times more acidic as pH 3

orange juice,
Tomato juice, acid rain
Black coffee
Urine, saliva
PURE water
Salt water
Baking soda
Great Salt Lake
Ammonia
Soapy Water
Bleach
Liquid Drain Cleaner
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Neutralization

• Acid Base ? Salt H2O
• A salt is a metal and non-metal (not just NaCl)
• HCl NaOH ? NaCl H2O
• HCl Ca(OH)2 ? CaCl2 H2O

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Titrations

• Technique used by chemists to determine an
  unknown molarity of a substance
• We can use an indicator (changes color) to tell
  us when we are neutral (moles of acid moles of
  base)
• link

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Titration Calculations

• Moles of Acid Moles of Base
• M1V1M2V2

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Titration Problemsacid baseM1V1 M2V2

• 1. What is the molarity of a CsOH solution if
  30.0mL of the solution is neutralized by 26.4 mL
  of a 0.250 M HBr solution?

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Titration Problemsacid baseM1V1 M2V2

• 2. What is the molarity of a nitric acid if 43.33
  mL 0.100 M KOH solution is needed to neutralize
  20.0mL of HNO3?

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Titration Problemsacid baseM1V1 M2V2

• 3. What is the concentration of a household
  ammonia cleaning solution if 49.9 mL 0.59 M HCl
  is required to neutralize 25.00 mL solution?

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Titration Problemsacid baseM1V1 M2V2

• 4. What is the molarity of an NaOH solution if 50
  mL of the solution is neutralized by 37 mL of 0.5
  M HCl?