Upload
kory-perry
View
221
Download
0
Embed Size (px)
Citation preview
Acids Acids and and
BasesBases
Acids:Acids: Compounds that Compounds that dissociate (give off) one or dissociate (give off) one or more more hydrogen ionshydrogen ions (H+) (H+) when dissolved in water when dissolved in water (proton donors)(proton donors)
Bases:Bases: Compounds that Compounds that dissociate (give off) one or dissociate (give off) one or more more hydroxide ionshydroxide ions (OH-) (OH-) when dissolved in water when dissolved in water (proton acceptors)(proton acceptors)
The pH ScaleThe pH Scale
pH is a measure of H+ ion concentration.
The formula for calculating pH is:
pH = -log[H+]
The pH ScaleThe pH Scale
pH = -log[H+]
I Do: A solution has a hydrogen ion concentration of 0.001 M. What is the pH of this solution?____
We Do: What is the pH of a solution with a hydrogen ion concentration of 0.0001 M?_______
You Do: What is the pH value of a solution that has a hydrogen ion concentration of 0.0000005 M?_______
The pH ScaleThe pH Scale
Acids have a pH value less than 7. Bases have a pH value greater than 7. Neutral substances have a pH of exactly 7. (Alkaline is another way to say basic)
pH IndicatorspH Indicators
An An indicator indicator is a compound used to detect the presence of His a compound used to detect the presence of H++ ions in solution. Indicators typically change color when ions in solution. Indicators typically change color when exposed to acids and bases and can be used to determine exposed to acids and bases and can be used to determine whether a substance is acidic, basic, or neutral. Some whether a substance is acidic, basic, or neutral. Some common indicators are:common indicators are:
Litmus paper (turns red when exposed to acid, blue when Litmus paper (turns red when exposed to acid, blue when exposed to base) exposed to base)
Phenolphthalein (clear = acid, pink = base)Phenolphthalein (clear = acid, pink = base)
Universal indicator (red = acid, blue = base) Universal indicator (red = acid, blue = base) Bromothymol blue (yellow = acid, blue = base) Bromothymol blue (yellow = acid, blue = base)
Cyanidin (red cabbage juice) (red = acid, yellow/green = Cyanidin (red cabbage juice) (red = acid, yellow/green = base) Phenol red (yellow = acid, red = base) Phenol red (yellow = acid, red = base) base)
Properties of AcidsProperties of Acids
Acids taste sourAcids have a pH lower than 7Acids effect indicators
Blue litmus turns redUniversal indicator turns red
Properties of AcidsProperties of Acids
Acids are proton (hydrogen ion, H+) donors Acids react with active metals, produce H2
Acids react with carbonates Acids neutralize bases
Acids Effect IndicatorsAcids Effect Indicators
Blue litmus paper turns red in contact with an acid.
Acids Acids Have a pH Have a pH less than less than
77
Properties of BasesProperties of Bases Bases taste bitterBases have a pH greater than 7 Bases effect indicators
Red litmus turns blueUniversal indicator turns bluePhenolphthalein turns purple
Properties of BasesProperties of Bases
Bases are proton (H+) acceptors and usually have hydroxide ions- OH- Solutions of bases feel slippery Bases neutralize acids
Bases Effect Bases Effect IndicatorsIndicators
Red litmus paper turns blue in contact with a base. Phenolphthale
in turns purple in a base.
Bases Bases have a pH have a pH
greater greater than 7than 7
Common Strong AcidsCommon Strong Acids
Sulfuric Acid, H2SO4
Perchloric acid, HClO4
Hydrochloric Acid, HCl
Hydrobromic Acid, HBr
Nitric Acid, HNO3
Hydroiodic Acid, HI
Common Strong BasesCommon Strong Bases
Lithium Hydroxide, LiOH Sodium Hydroxide, NaOH
Potassium Hydroxide, KOH Calcium Hydroxide Ca(OH)2
Strontium Hydroxide, Sr(OH)2 Barium Hydroxide, Ba(OH)2
Common Weak AcidsCommon Weak Acids
Formic Acid, HCOOH
Acetic Acid, CH3COOH
Hydrofluoric, Acid HF
Hydrocyanic acid, HCN
Common Weak BasesCommon Weak Bases
Sodium hydroxide, NaOH Ammonia, NH3
Potassium hydroxide, KOH Calcium hydroxide, Ca(OH)2
Formation of Formation of HydroniumHydronium ion, ion, HH33OO++
H2O + HCl H3O+ + Cl-
Protondonor
Protonacceptor
Hydronium
Acids and Bases Can Be Acids and Bases Can Be Strong or WeakStrong or Weak
Strong acids are assumed to be 100% ionized in solution (good proton donors).
Weak acids are usually less than 5% ionized in solution (poor proton donors).
HCl
H2SO4 HNO3
H3PO4 HC2H3O2 Organic acids
Strong Acid DissociationStrong Acid Dissociation
Weak Acid DissociationWeak Acid Dissociation
Acids Can Be Strong or WeakAcids Can Be Strong or Weak
Which acid is a Which acid is a strong acid?____________ strong acid?____________
How do you know?How do you know?
Which acid is a weak Which acid is a weak
acid? ___________acid? ___________
How do you know?How do you know?
Acids and Bases Can Be Acids and Bases Can Be Concentrated or DiluteConcentrated or Dilute
A concentrated solution contains a high amount of solute per liter of solution. Example: 12M HCl
A dilute solution contains a low amount of solute per liter of solution. Example: 0.01 M HCl
Acids and Bases Can Be Acids and Bases Can Be Concentrated or DiluteConcentrated or Dilute
Which solution is most concentrated? ___ How do you know?Which solution is lease concentrated?___How do you know?
A B
NeutralizationNeutralization
What happens when an acid is mixed with a base?
Neutralization!
Products of NeutralizationProducts of Neutralization
HCl + NaOH H2SO4 + Ca(OH)2
The products of neutralization are always a ______ and _______.
NaCl + H2O
CaSO4 + 2 H2O
salt water