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9sDdIaBhtgk-022|And my weak base solution.
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9sDdIaBhtgk-023|So the base turns this indicator blue.
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9sDdIaBhtgk-024|That's a nice little mnemonic to remember, because the bases are blue, both starting with the same letter.
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9sDdIaBhtgk-026|So that indicator in the strong acid, weak acid, water, weak base, and strong base solution.
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9sDdIaBhtgk-027|Now, the number of ions in each of these solutions is indicative of the acid and base strength, as well.
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9sDdIaBhtgk-028|HCl, remember, completely disassociates.
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9sDdIaBhtgk-029|So 0.1 molar HCl makes 0.1 molar H plus ions and 0.1 molar Cl minus ions.
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9sDdIaBhtgk-030|So I have 0.2 molar total ion concentration.
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9sDdIaBhtgk-031|And that ion concentration will make the solution conductive.
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9sDdIaBhtgk-032|So if I test the conductivity, just kind of qualitatively with this light bulb, I'll see that HCl, there's ions in there.
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9sDdIaBhtgk-033|Ions conduct, and I'll have a strongly conductive solution.
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9sDdIaBhtgk-035|And in general, water, pure, is not a conductive solution.
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9sDdIaBhtgk-036|So let's look at the weak acid.
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9sDdIaBhtgk-037|Now, the weak acid dissociates much less strongly than the strong acid.
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9sDdIaBhtgk-039|We should see the same correlation between the weak base and the strong base.
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9sDdIaBhtgk-045|A correlation between pH, color, and ionic strength for acid and base solutions.
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hTimaCA_A88-000|Let's look at the phase diagram of carbon dioxide and see if we can predict where the sublimation of carbon dioxide occurs at 1 atmosphere.
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hTimaCA_A88-004|We're trying to find the sublimation line, a sublimation at constant pressure, transition for carbon dioxide.
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hTimaCA_A88-005|Well, if it's a constant pressure transition, it has to be a horizontal line.
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hTimaCA_A88-006|And if it's a sublimation, it must cross the solid/gas transition line.
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hTimaCA_A88-007|Sublimation is the conversion from solid to gas.
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hTimaCA_A88-009|The correct answer here is A.
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--imKPteSwQ-000|When I burn the hydrocarbon butane, heat is released.
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--imKPteSwQ-009|We're talking about burning butane in oxygen, and in each case oxygen is in excess.
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--imKPteSwQ-010|So butane limits the amount of energy released.
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--imKPteSwQ-014|But the speed of the reaction and the overall energy release are independent.
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--imKPteSwQ-015|I can release a lot of energy over a long time, or release a small amount of energy quickly.
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-dpZipe4Hm0-000|Let's look at some of the molecular orbitals involved in forming multiple bonds.
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-dpZipe4Hm0-001|So when we have a carbon that's sp2 hybridized-- and I've drawn one here-- I have three equivalent sp2 orbitals.
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-dpZipe4Hm0-002|And I have a model that looks like that here.
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-dpZipe4Hm0-003|The three bonds here at 120 degrees from each other are sp2 hybrid orbitals.
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-dpZipe4Hm0-004|Now, sp2 hybrids leave behind one p.
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-dpZipe4Hm0-005|Sp2 hybrids are formed from an s and two p's.
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-dpZipe4Hm0-006|So there's an unchanged p orbital that I represented here by this plus minus lobe.
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-dpZipe4Hm0-012|I'll form a sigma bond between the two carbons.
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-dpZipe4Hm0-014|Those two atomic hybrid orbitals will form a sigma bonding and antibonding molecular orbital.
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-dpZipe4Hm0-015|So two atomic orbitals, both of them sp2, form two molecular orbitals, a sigma bonding and antibonding orbital.
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-dpZipe4Hm0-016|Now, the p orbital left over can overlap to form a pi bond, a second bond.
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-dpZipe4Hm0-017|And remember, pi bonds are bonds that are above and below the internuclear axis, usually formed by p orbitals.
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-dpZipe4Hm0-019|There.
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-dpZipe4Hm0-020|There is the sp sigma bond.
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-dpZipe4Hm0-021|And now the p orbitals can overlap and form a bond above and below the axis, a second bond.
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-dpZipe4Hm0-022|So I have a sigma and a pi bond.
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-dpZipe4Hm0-023|The first bond formed between atoms is always sigma.
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-dpZipe4Hm0-024|Other bonds are pi.
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-dpZipe4Hm0-030|So multiple bonds, a sigma and a pi bond, formed from a combination of hybrid orbitals and leftover p orbitals on carbon.
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oTCKWNiWdus-000|Just like the entropy and the enthalpy, the free energy is a state function.
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oTCKWNiWdus-002|Now, here's a table of standard free energies of formations.
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oTCKWNiWdus-004|That's because it wouldn't be fair to take the reactants at, say, two or three atmospheres of pressure and compare that to the products at half an atmosphere of pressure.
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oTCKWNiWdus-005|We compare everything across the board in a standard state of conditions.
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oTCKWNiWdus-006|So in a sense, it makes it a little artificial.
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oTCKWNiWdus-008|And that's not necessarily how you set it up in the laboratory, but it'll still help you determine whether overall the products or the reactants are favored.
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oTCKWNiWdus-009|If delta g is overall negative, then the products are favored.
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oTCKWNiWdus-010|So here we have the tables now of enthalpy, entropy, and free energy.
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oTCKWNiWdus-011|So we can use these to calculate free energies, standard state enthalpies, and standard entropy differences.
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ma-MKQ2TAGk-000|Our bodies use the metabolism of glucose as an energy source.
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ma-MKQ2TAGk-002|Now, that oxidation that's down hill in free energy, and that's coupled to an uphill in free energy reaction.
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ma-MKQ2TAGk-003|The phosphorylation, the addition of a phosphate group, to adenosine diphosphate to form adenosine triphosphate.
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ma-MKQ2TAGk-007|So ATP hydrolysis from ATP to ADP, that releases energy.
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ma-MKQ2TAGk-008|And that can be coupled with building something in your cells.
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ma-MKQ2TAGk-009|So for instance, taking free amino acids and making them into proteins.
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ma-MKQ2TAGk-010|So free amino acids are small individual molecules.
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ma-MKQ2TAGk-011|They're linked together to form proteins.
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ma-MKQ2TAGk-012|And proteins are molecules that are catalysts in our body and they're structural in your body.
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ma-MKQ2TAGk-013|They're a very important molecule in your body.
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ma-MKQ2TAGk-015|For protein synthesis, it turns out that about four moles of ATP are hydrolyzed for every peptide bond that's formed.
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ma-MKQ2TAGk-016|Now, the peptide bond is the bond between the amino acids.
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ma-MKQ2TAGk-017|So as you build up a protein, you add amino acids.
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ma-MKQ2TAGk-018|For each amino acid you add, you need to form a peptide bond.
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ma-MKQ2TAGk-019|And for each peptide bond you form, you hydrolyze about four moles of ATP.
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ma-MKQ2TAGk-020|So that's an overall accounting of how energy is used in your cells.
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cLXnZlwrU04-000|Let's look at a gas phase equilibrium.
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cLXnZlwrU04-001|Here's the reaction of nitrogen and hydrogen to form ammonia.
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cLXnZlwrU04-002|Now, this reaction is important industrially, because nitrogen, although it's abundant-- there's 70% of it in the air we breathe-- it's unreactive.
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cLXnZlwrU04-003|There's a triple bond in N2.
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cLXnZlwrU04-004|It's an unreactive molecule.
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cLXnZlwrU04-005|But nitrogen is required for all life.
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cLXnZlwrU04-006|It's in our proteins and DNA.
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cLXnZlwrU04-007|So getting nitrogen from this unreactive form to a reactive form is important in both nature and industry.
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cLXnZlwrU04-008|In industry, to make fertilizers, and in nature, to fix the nitrogen so plants and animals can grow.
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cLXnZlwrU04-009|This nitrogen fixation reaction is exothermic.
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cLXnZlwrU04-010|It releases 92 kilojoules per mole of nitrogen that reacts.
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cLXnZlwrU04-014|Raising the temperature increases the motion of the molecules and accelerates the kinetics of the reaction.
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cLXnZlwrU04-015|But you're fighting thermodynamics, because as you raise the temperature, an exothermic chemical reaction will tend to favor the reactants.
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cLXnZlwrU04-016|So K decreases.
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cLXnZlwrU04-017|So you start to favor reactants as the temperature increases.
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cLXnZlwrU04-018|So you want to fight that, and one way to do it is to raise the pressure.
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cLXnZlwrU04-019|Le Chatelier's principle tells you if you raise the pressure, you're going to favor the ammonia side.
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cLXnZlwrU04-020|And why is that?
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cLXnZlwrU04-021|Well, raising the pressure, you have 4 moles of gas on this side and 2 moles of gas on this side.
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cLXnZlwrU04-022|So the product side is favored.
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cLXnZlwrU04-023|It would shift towards products to relieve that high pressure situation, shift towards the fewer molecules.
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cLXnZlwrU04-026|That will efficiently balance the kinetics, the speed of the reaction, and the thermodynamics that are tending to make it favor reactants.
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6DGPuhFoiJI-000|Let's take a week acid, acetic acid, originally at pH 3, dilute it by a factor of 10, and ask what is the new pH?
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6DGPuhFoiJI-001|So acetic acid, pH 3, dilute with water a factor of 10.
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6DGPuhFoiJI-012|Well, the pH is 3, so the H3O plus concentration is 10 to the minus 3.
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6DGPuhFoiJI-016|This reaction favors the reactants.
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6DGPuhFoiJI-017|So to get a product concentration of 10 to the minus 3, we have to have a much higher reactant concentration.
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6DGPuhFoiJI-018|We think that's to be the case.
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6DGPuhFoiJI-019|Now we dilute it.
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