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II
III
I Hydrogen Bonding and The Nature of Solutions
Ch. 13 & 14 - SolutionsCh. 13 & 14 - Solutions
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Hydrogen BondingHydrogen Bonding
A hydrogen atom that is bonded to a highly electronegative atom (such as oxygen) is attracted to an unshared pair of electrons of an electronegative atom in a nearby molecule
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Hydrogen BondingHydrogen Bonding
Due to the small size of the hydrogen atom, it can become very close to an unshared pair of electrons on the adjacent molecule
Compounds with this type of force have unusually high boiling points.
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Hydrogen bondingHydrogen bonding
Hydrogen bonding is what gives water its unusual properties such as :• High boiling point/ melting point • Great surface tension• Amphoteric (can be an acid or a base.)• High polarity• Known as “the universal solvent”
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Hydrogen bondingHydrogen bonding
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A. DefinitionsA. Definitions
Solution - Solution - homogeneous mixture
Solvent Solvent - present in greater amount
Solute Solute - substance being dissolved
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A. DefinitionsA. Definitions
Solute Solute - KMnO4Solvent Solvent - H2O
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B. SolvationB. Solvation
Solvation – Solvation – the process of dissolving
solute particles are separated and pulled into solution
solute particles are surrounded by solvent particles
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B. SolvationB. Solvation
StrongElectrolyte
Non-Electrolyte
solute exists asions only
- +
salt
- +
sugar
solute exists asmolecules
only
- +
acetic acid
WeakElectrolyte
solute exists asions and
molecules DISSOCIATION IONIZATION
View animation online.9
B. SolvationB. Solvation
DissociationDissociation• separation of an
ionic solid into aqueous ions
NaCl(s) Na+(aq) + Cl–(aq)
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B. SolvationB. Solvation
IonizationIonization• breaking apart of
some polar molecules into aqueous ions
HNO3(aq) + H2O(l) H3O+(aq) + NO3–(aq)
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B. SolvationB. Solvation
Molecular Molecular SolvationSolvation• molecules
stay intact
C6H12O6(s) C6H12O6(aq)
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B. SolvationB. Solvation
NONPOLAR
NONPOLAR
POLAR
POLAR
““Like Dissolves Like”Like Dissolves Like”““Like Dissolves Like”Like Dissolves Like”
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B. SolvationB. Solvation
Soap/DetergentSoap/Detergent• polar “head” with long nonpolar “tail”• dissolves nonpolar grease in polar water
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C. SolubilityC. Solubility
SATURATED SOLUTION
no more solute dissolves
UNSATURATED SOLUTIONmore solute dissolves
SUPERSATURATED SOLUTION
becomes unstable, crystals form
concentration15
C. SolubilityC. Solubility
SolubilitySolubility• maximum grams of solute that will
dissolve in 100 g of solvent at a given temperature
• varies with temp• based on a saturated solution
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C. SolubilityC. Solubility
Solubility CurveSolubility Curve• shows the
dependence of solubility on temperature
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C. SolubilityC. Solubility
Solids are more soluble at...Solids are more soluble at...• high temperatures.
Gases are more soluble at...Gases are more soluble at...• low temperatures &• high pressures
(Henry’s Law).• EX: nitrogen narcosis,
the “bends,” soda18
