Chapter 13: Control of Solubility Many of the forces weve talked about occur between ions/molecules in solutions Definition: A homogeneous mixture (only one phase) Examples: saltwater, tap water, gemstones, brass, air
Made up of a solvent and a solute: Solvent: the substance present in the larger amount. Solute: the other substance Dissolving depends on attractive forces and entropy
What well cover: Definitions Control of Solubility Things that affect solubility Part 1: Definitions There is a maximum amount of any solute that will dissolve in
a given solvent If less than the maximum has been added, solution is unsaturated If the max or more than the max has been added, solution is saturated Can also have Supersaturated solutions The concentration of a solution is the amount of solute that has
been dissolved in a solvent. Many units of concentration: molarity (mol/L), weight % (g/g), ppm (mg/L) Solubility If a solute will dissolve in a solvent, it is soluble. Some solutes have limits,
some are infinitely soluble in a solvent. Sugar: 200 g in 100 mL water at 20 C Ethanol: infinitely soluble in water Gases are infinitely soluble in one another Trends and Control of Solubility For now, we are examining molecular compounds- not ionic compounds.
General rules: 1. polar solutes dissolve in polar solvents 2. nonpolar solutes dissolve in nonpolar solvents Like dissolves Like Oil and water dont mix: is oil polar or nonpolar? You try: which of these will dissolve in water?
CH3OH CH3CH3 NH3 Hydrophilic
Hydrophobic Which of these will not dissolve in water? 1. NH3 2. CH3CH3
3. CH3OH Which of these is least soluble in water? 1. CH3OH 2. CH3CH2CH2OH 3. CH3CH2CH2CH2OH
Which of these is least soluble in water? 1. CH3OH 2. CH3CH2CH2OH 3. CH3CH2CH2CH2OH
Introduction to Thermodynamic Control of the World Enthalpy, H: Stronger bonds/IMFs are favored over weak ones. Entropy, S: Freedom of movement is favored over constrained states. Trends and Control of
Solubility and Mixing: Why do some things mix and others do not? What controls Solubility: Enthalpy (enthalpy of solution)
Negative if new forces are stronger than original forces Entropy Depends on the entropy change of both the water and the solute. Effects of Polarity
Why dont water and oil mix? 1. Enthalpy: Water wants to keep Hbonds 2. Entropy: Water wont form constricted arrangements
Why do Proteins Fold? Without lipids, youd fall apart. What holds DNA together?
DNA Base Pairs DNA Base Pairs: Hydrogen Bonding What holds DNA together? 1. 2.
3. 4. H bonds Other bonds Entropy of DNA Entropy of water
92% 7% 0% 1
2 3 1% 4
DNA, H-Bonding, and Entropy Break week is 1. Needed 2. Waste of time 3. Good to go to work
68% 18% 1
2 14% 3 Introduction to Polymers
Polymers are long molecules made of repeating units, called monomers. In general: Specific example: Forces between polymer chains: Crosslinks
Weak: Intermolecular force crosslinks Strong: Colvalent bond crosslinks
Common Addition Polymers Polyethylene PVC Polystyrene
Acrylics Polar Whites! Condensation Polymers: General Idea
Common Condensation Polymers Polyamides: nylon Polyesters How plastics are made monomers polymers melt form cool and sometimes set
blow molding injection molding extrusion Laundry!
Hard Water and Phosphate Solubility Fabric Softener and Hair Conditioner: Cationic Surfactants Colloids: mixture of different phases
that do not separate Emulsions: water/oil mixtures that do not separate surface proteins
Part 2: External Control of Solubility Temperature and Pressure Predictions: Will solubility increase or decrease with increasing temperature? Will solubility of a gas increase or decrease with increasing pressure?
Will solubility increase with increasing temperature? 1. Yes 2. No 3. sometimes 33%
1 33% 2
33% 3 Will solubility increase with increasing pressure? 1. Yes
2. No 3. sometimes 33% 1
33% 2 33% 3
Will solubility of gases increase with increasing temperature? 33% 33%
33% 1. Yes 2. No 3. sometimes 1
2 3 Chemical Hot Packs
What is the solubility of O2 in grams per liter, given normal atmospheric conditions? Henrys Law Constants: when are they constant? Which is greater, kH for O2 at 20 oC or O2 at 50 oC? Which is greater, kH for O2 or kH for NH3?
Family Radio Service (FRS) Advantages. Inexpensive. Widely used. No license required. Range up to 1 mile (varies with terrain) 14 channels. Shared communication with GMRS radios. Best used for intra-team communications. CERT . Emergency Communications
Cottonmouth - water moccasin Piedmont Habitat - Trees The Live Oak is Georgia's state tree Georgia Pine Trees Sweet Gum Dogwood Piedmont Plants Cherokee Rose Iris Azaleas Georgia Mountains Habitat The mountains in Georgia were formed over a billion years...
Water on the Surface Oxbow Lake Oxbow Lake What is a river system? A river system includes a river in addition to any streams or tributaries that flow into that river. Tributary The smaller streams and rivers that feed into...
domain model . gives . details of . the . systems structural . characteristics (system parts and their. arrangement) The next step is to model the inside of the system. We do this by building the . domain model, which...
It registers a request only if the interrupt is unmasked. Normally IR0 has highest priority and IR7 has the lowest priority. The priorities of the interrupt request input are also programmable. First the 8259 should be programmed by sending Initialization...
Ready to download the document? Go ahead and hit continue!