notes – properties of water: solubility/acids-bases
TRANSCRIPT
Notes – Properties of Water:
Solubility/Acids-Bases
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Properties of Water
• Hydrogen Bonds – Weak forces between some covalently bonded molecules (polar molecules)
Properties of Water
• Properties of Water
• Cohesion – polar molecules attract and stick together
• Adhesion – water molecules stick to other molecules
• Examples
Surface tension, capillary action, high boiling point, water in sphere droplets, high heat capacity (storage)
Fig. 3-3
Water-conductingcells
Adhesion
Cohesion
150 µm
Directionof watermovement
Fig. 3-4
Properties of Water
Solutions - Mixtures in which one or more substances are uniformly distributed in another.
• A Solute is dissolved in a solvent.
• Examples:
Aqueous solutions (water solvent), blood plasma, plant sap, seawater.
Properties of Water
• Properties of Water• Universal solvent –
More substances dissolve in water than any other molecule.
• Solvent – The substance other substances dissolve in.
• Solute – The substance being dissolved
Properties of Solutions
• Properties of Water• Universal solvent –
More substances dissolve in water than any other molecule.
• Solvent – The substance other substances dissolve in.
• Solute – The substance being dissolved
Properties of Solutions
• Properties of Water• Universal solvent –
More substances dissolve in water than any other molecule.
• Solvent – The substance other substances dissolve in.
• Solute – The substance being dissolved
Properties of Solutions
• Properties of Water• Universal solvent –
More substances dissolve in water than any other molecule.
• Solvent – The substance other substances dissolve in.
• Solute – The substance being dissolved
Properties of Solutions
Solution are said to be:• Homogeneous mixtures – they look the “same” throughout
Examples: Salt water, coffee, orange juice• Mixtures that look “different” are called:• Heterogeneous mixtures
Properties of Solutions
Solution are said to be:• Homogeneous mixtures – they look the “same” throughout
Examples: Salt water, coffee, orange juice• Mixtures that look “different” are called:• Heterogeneous mixtures
Solutions
• Colloid - The type of mixture which contains small solid particles suspended in a solution.
• Example: Milk, fog, gelatin
Solutions
• Suspension -A type of heterogeneous mixture where the solid particles are large enough to settle out or can be separated by using filtration.
• Ex: Snow globe, muddy water
Salt in Water
• Salt in water dissolves and becomes positive and negative ions.
• Saltwater conducts electricity
Salt in Water
• Salt in water dissolves and lowers the freezing point of water.– Ex: Applying salt on icy
roads causes ice to melt
• Salt in water dissolves and raises the boiling point of water
Salt in Water
• Salt in water dissolves and lowers the freezing point of water.– Ex: Applying salt on icy
roads causes ice to melt
• Salt in water dissolves and raises the boiling point of water– Ex: Adding salt to water
makes water boil hotter and cooks food faster
Salt in Water
• Salt in water dissolves and lowers the freezing point of water.– Ex: Applying salt on icy
roads causes ice to melt
• Salt in water dissolves and raises the boiling point of water
Salt in Water
• Salt in water dissolves and lowers the freezing point of water.– Ex: Applying salt on icy
roads causes ice to melt
• Salt in water dissolves and raises the boiling point of water– Ex: Adding salt to water
makes water boil hotter and cooks food faster
Solubility – The maximum quantity of a substance that will dissolve in a certain
quantity of water at a specified temperature
• Solubility curve – Graphical representation of the amount of solute that dissolves in a given amount of solvent
Solubility – The maximum quantity of a substance that will dissolve in a certain
quantity of water at a specified temperature
• Solubility curve – Graphical representation of the amount of solute that dissolves in a given amount of solvent
Concentration – How much solute is dissolved in a specific quantity of solvent or
solutionSolubility can be
measured in :• per cent % - parts per
hundred• ppm – parts per
million• ppb – parts per billion
Solubility - concentrations depend on the amount/type of solvent and
the temperature• Saturated – solutions
holding the maximum amount of solute
• Unsaturated – solutions holding less than the max. amount
• Supersaturated – solutions holding more than the max amount of solute
Solubility - concentrations depend on the amount/type of solvent and
the temperature• Saturated – solutions
holding the maximum amount of solute
• Unsaturated – solutions holding less than the max. amount
• Supersaturated – solutions holding more than the max amount of solute
Solubility - concentrations depend on the amount/type of solvent and the
temperature• Saturated – solutions
holding the maximum amount of solute
• Unsaturated – solutions holding less than the max. amount
• Supersaturated – solutions holding more than the max amount of solute
Solubility
Solubility
• Substances that dissolve in H2O are soluble.
• If substances do not dissolve in water they are insoluble.
• Substances that dissolve in water are ionic compounds or other polar molecules
Solubility
• Substances that dissolve in H2O are soluble.
• If substances do not dissolve in water they are insoluble.
• Substances that dissolve in water are ionic compounds or other polar molecules
• Ex: Salts, Alcohol
Solubility
• Nonpolar substances do not have partial charges.
• They do not readily dissolve in water
• Nonpolar substances include oils, petroleum products, kerosene
Solubility
• Nonpolar substances will dissolve in other nonpolar substances.
• Ex: Paint thinner for oil-based paints
• Like dissolves in like
• Soap breaks nonpolar molecules into smaller particles to make them more soluble in water
Solubility
• Nonpolar substances will dissolve in other nonpolar substances.
• Ex: Paint thinner for oil-based paints
• Like dissolves in like
• Soap breaks nonpolar molecules into smaller particles to make them more soluble in water
Measuring Solubility
Water Dissociation – Self Ionization
• Water can break down into ionized particles
H20 (l) = H+ (aq) + OH- (aq)
H20 + H+ = H30 +
Hydronium ion
ACID / BASE
• Acid/Base – Special compounds containing excess :
• Hydrogen (H+) (H30+ ) (hydronium) (acids)
or • Hydroxide (OH-) ions
(charged particles) dissolved in water (base)
ACID / BASE
• Acid/Base – Special compounds containing excess :
• Hydrogen (H+) (H30+ ) (hydronium) (acids)or
• Hydroxide (OH-) ions (charged particles) dissolved in water (base)
ACID / BASE
• Acid/Base – Special compounds containing excess :
• Hydrogen (H+) (H30+ ) (hydronium) (acids)or
• Hydroxide (OH-) ions (charged particles) dissolved in water (base)
• pH = Scale to measure H+ concentration (-log)
• pH 1= 1/10=1/101 H+• pH 2 = 1/100=1/102
• pH 3 = 1/1000= 1/103
• pH 1 = highest H+
• pH 14= lowest H+
ACID / BASE
• Acid/Base – Special compounds containing excess :
• Hydrogen (H+) (H30+ ) (hydronium) (acids)or
• Hydroxide (OH-) ions (charged particles) dissolved in water (base)
• pH = Scale to measure H+ concentration (-log)
• pH 1= 1/10=1/101 H+
• pH 2 = 1/100=1/102
• pH 3 = 1/1000= 1/103
• pH 1 = highest H+
• pH 14= lowest H+
ACID / BASE
• Acid/Base – Special compounds containing excess :
• Hydrogen (H+) (hydronium) (acids)or
• Hydroxide (OH-) ions (charged particles) dissolved in water (base)
• pH = Scale to measure H+ concentration (-log)
• pH 1= 1/10=1/101 H+
• pH 2 = 1/100=1/102
• pH 3 = 1/1000= 1/103
• pH 1 = highest H+
• pH 14= lowest H+
Acids
• Made up of molecules including one or more hydrogen (H+) (H30+ ) atoms that can be easily released in water solutions
• Substances in common have a sour taste
• Ex: Lemons, vinegar
Acid / Base• Acid (H+) (H30+ ) =
Hydronium ion• pH 1-6• 1 is strongest , 6 is
weakest
Acids
• Made up of molecules including one or more hydrogen (H+) (H30+ ) atoms that can be easily released in water solutions
• Substances in common have a sour taste
• Ex: Lemons, vinegar
• Acids contain (H+) ions and compounds are renamed as acids
• Example:• HCl = Hydrogen
Chloride
renamed:
Hydrochloric Acid
Naming and Writing Acids and Bases
• Acids- Compounds that contain one or more Hydrogen atoms and produce Hydrogen ions (H+) when dissolved in water.
• Formula HnX• H = Hydrogen• n = Subscript (# of H)• X = Monatomic or
Polyatomic anion
Naming and Writing Acids and Bases
• Acids- Compounds that contain one or more Hydrogen atoms and produce Hydrogen ions (H+) when dissolved in water.
• Formula HnX• H = Hydrogen• n = Subscript (# of H)• X = Monatomic or
Polyatomic anion
Naming and Writing Acids and Bases
• Naming Acids
1) If anion ends in –ide: begin with Hydro- , change anion to – ic, and add “acid”
HCl = Hydrogen Chloride
= Hydrochloric Acid
HBr =
H2S =
Naming and Writing Acids and Bases
• Naming Acids
1) If anion ends in –ide: begin with Hydro- , change anion to – ic, and add “acid”
HCl = Hydrogen Chloride
= Hydrochloric Acid
HBr = Hydrogen Bromide = Hydrobromic Acid
H2S =
Naming and Writing Acids and Bases
• Naming Acids
1) If anion ends in –ide: begin with Hydro- , change anion to – ic, and add “acid”
2) If anion ends in –ite: anion changes to –ous followed by “acid”
HCl = Hydrogen Chloride
= Hydrochloric Acid
HBr = Hydrobromic Acid
H2S = Hydrogen Sulfide
=Hydrosulfuric Acid
Naming and Writing Acids and Bases
• Naming Acids
2) If anion ends in –ite: anion changes to –ous followed by “acid”
H2SO3 = Hydrogen Sulfite
= Sulfurous Acid
HNO2 =
HClO2 =
Naming and Writing Acids and Bases
• Naming Acids
2) If anion ends in –ite: anion changes to –ous followed by “acid”
H2SO3 = Hydrogen Sulfite
= Sulfurous Acid
HNO2 = Hydrogen
Nitrite
= Nitrous Acid
HClO2 =
Naming and Writing Acids and Bases
• Naming Acids
2) If anion ends in –ite: anion changes to –ous followed by “acid”
3) If anion ends in –ate: anion changes to –ic followed by “acid”.
H2SO3 = Hydrogen Sulfite
= Sulfurous Acid
HNO2 = Hydrogen Nitrite
= Nitrous Acid
HClO2 = Hydrogen chlorite
= Chlorous Acid
Naming and Writing Acids and Bases
• Naming Acids
3) If anion ends in –ate: anion changes to –ic followed by “acid”.
H2SO4 = Hydrogen Sulfate
= Sulfuric Acid
HNO3 =
H3PO4 =
Naming and Writing Acids and Bases
• Naming Acids
3) If anion ends in –ate: anion changes to –ic followed by “acid”.
H2SO4 = Hydrogen Sulfate
= Sulfuric Acid
HNO3 = Hydrogen Nitrate
= Nitric Acid
H3PO4 =
Naming and Writing Acids and Bases
• Naming Acids
3) If anion ends in –ate: anion changes to –ic followed by “acid”.
H2SO4 = Hydrogen Sulfate
= Sulfuric Acid
HNO3 = Hydrogen Nitrate
= Nitric Acid
H3PO4 = Hydrogen
Phosphate
= Phosphoric Acid
Acids
Formula name
HCl =
H2CO3 =
HC2H3O2 =
HNO2 =
H3PO3 =
H2SO4 =
HBr =
Acid Name
HCl =
H2CO3 =
HC2H3O2 =
HNO2 =
H3PO3 =
H2SO4 =
HBr =
Acids
Formula name
HCl = Hydrogen Chloride
H2CO3 = Hydrogen Carbonate
HC2H3O2 = Hydrogen Acetate
HNO2 = Hydrogen Nitrite
H3PO3 = Hydrogen Phosphite
H2SO4 = Hydrogen Sulfate
HBr = Hydrogen Bromide
Acid Name
HCl = Hydrochloric Acid
H2CO3 = Carbonic Acid
HC2H3O2 = Acetic Acid
HNO3 = Nitrous Acid
H3PO3 = Phosphorous Acid
H2SO4 = Sulfuric acid
HBr = Hydrobromic Acid
Bases
• Ionic substances that include (OH-) hydroxide ions or generate (OH-) ions in solution
• In common substances have a bitter taste and slippery feel
• Ex: soap, peppers
Naming Bases
• Bases – Ionic compounds that produce hydroxide ions (OH-) in solution
Naming Bases
• Bases – Ionic compounds that produce hydroxide ions (OH-) in solution
• Naming bases:
Bases follow the same rules as ionic compounds
Naming Bases
• Naming bases:
Bases follow the same rules as ionic compounds.
Name metal or polyatomic cation, name polyatomic anion
• NaOH = Sodium Hydroxide
• Ca(OH)2 =
• NH4(OH)
Naming Bases
• Naming bases:
Bases follow the same rules as ionic compounds.
Name metal or polyatomic cation, name polyatomic anion
• NaOH = Sodium Hydroxide
• Ca(OH)2 = Calcium Hydroxide
• NH4(OH) =
Naming Bases
• Naming bases:
Bases follow the same rules as ionic compounds.
Name metal or polyatomic cation, name polyatomic anion
• NaOH = Sodium Hydroxide
• Ca(OH)2 = Calcium Hydroxide
• NH4(OH) = Ammonium
Hydroxide
Bases
• Ionic substances that include (OH-) hydroxide ions or generate (OH-) ions in solution
• In common substances have a bitter taste and slippery feel
• Ex: soap, peppers
• Bases keep their original compound name
• Ca(OH)2 =
• Mg(OH)2 =
• KOH =
• NaOH =
Bases
• Ionic substances that include (OH-) hydroxide ions or generate (OH-) ions in solution
• In common substances have a bitter taste and slippery feel
• Ex: soap, peppers
• Bases keep their original compound name
• Ca(OH)2 = Calcium Hydroxide
• Mg(OH)2 = Magnesium
Hydroxide• KOH = Potassium Hydroxide
• NaOH = Sodium Hydroxide
• Base (OH-) = Hydroxide ion
• pH 8-14• 14 is strongest, 8 is
weakest
Acid / Base• Acid (H+) =
Hydronium ion• pH 1-6• 1 is strongest , 6 is
weakest
• Base (OH-) = Hydroxide ion
• pH 8-14• 14 is strongest, 8 is
weakest
Neutral pH
• pH 7
• H+ = (OH)- = neutral
H+ + (OH)- =HOH=H2O
Ex: Distilled water
pH indicators
Indicators – show pH with color changes. H+ or (OH)- concentrationsEx: Litmus paper, phenolphthalein
Acid / Base
• Neutralization Equation• Reactants Products• 1M HCl + 1M NaOH =
1M NaCl + 1M H2O
• Acid + Base = Salt + Water• pH1 pH14 pH7 pH7
• Buffer – Baking Soda (HCO3-) prevents pH change
• Titration – adding known quantities of acids and/or bases together to determine M or pH quantities
Acid / Base
• Neutralization Equation• Reactants Products
• HCl + NaOH = NaCl + H2O
• Acid Base Salt Water• pH1 pH14 pH7 pH7
• Buffer – Baking Soda (HCO3-) prevents pH change
ACID / BASE
• Acid/Base – Special compounds containing excess :
• Hydrogen (H+) (hydronium) (acids)or
• Hydroxide (OH-) ions (charged particles) dissolved in water (base)
ACID / BASE
• Acid/Base – Special compounds containing excess :
• Hydrogen (H+) (hydronium) (acids)or
• Hydroxide (OH-) ions (charged particles) dissolved in water (base)
• pH = Scale to measure H+ concentration (-log)
• pH 1= 1/10=1/101 H+• pH 2 = 1/100=1/102
• pH 3 = 1/1000= 1/103
• pH 1 = highest H+
• pH 14= lowest H+