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inLhIqLOouY-015|Here it's a product.
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inLhIqLOouY-016|Here it's a reactant.
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inLhIqLOouY-017|But the stronger the acid, the more that ion should be favored.
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inLhIqLOouY-018|Now, let's look at the two.
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inLhIqLOouY-019|If I look at Ka and Kb, they're not the reciprocals of each other.
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inLhIqLOouY-020|That is Ka is not 1/Kb.
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inLhIqLOouY-026|So now, I have analytically that the product Ka times Kb is a constant.
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inLhIqLOouY-027|So if Ka gets larger, a stronger acid, Kb must get smaller.
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inLhIqLOouY-028|So I have an analytical expression for strong acid means a weaker conjugate base.
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ZpzjU4NfAhw-000|So let's look at the various orbitals of a hydrogen atom.
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ZpzjU4NfAhw-001|Now, remember each orbital is a specific wave function, and that wave function will be described by three quantum numbers-- n, l, and m sub l.
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ZpzjU4NfAhw-002|Once I give you three quantum numbers, you should be able to tell me the orbital.
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ZpzjU4NfAhw-003|So let's look at them in sequence.
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ZpzjU4NfAhw-004|For n equal 1-- that's the ground state, the lowest possible energy level-- we'll have one value of l.
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ZpzjU4NfAhw-005|Now, remember l goes from 0 to n minus 1.
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ZpzjU4NfAhw-006|So if n is 1, the only possible value of l is 0.
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ZpzjU4NfAhw-007|So for n equal 1, we can have l equal 0.
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ZpzjU4NfAhw-008|And we're also going to use the designation s for the quantum number l.
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ZpzjU4NfAhw-009|So if I say l is s or if I say l is 0, I'm saying the same thing.
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ZpzjU4NfAhw-010|You have to memorize that little connection.
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ZpzjU4NfAhw-011|Now, for l equals 0, the only possible values of m sub l are 0.
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ZpzjU4NfAhw-012|Remember, m sub l goes in integer steps from minus l to l.
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ZpzjU4NfAhw-014|So now we have three quantum numbers that describes an orbital, and we're going to call this orbital the 1s orbital.
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ZpzjU4NfAhw-015|We're going to use the designations of the quantum numbers to describe the orbitals.
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ZpzjU4NfAhw-016|What does that look like?
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ZpzjU4NfAhw-017|Well, it turns out it's spherically symmetric.
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ZpzjU4NfAhw-018|The 1s orbital-- in fact, all s orbitals are spherical symmetric.
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ZpzjU4NfAhw-019|Remember, the l quantum number-- in this case, 0 equal to s-- that gives you something to understand the shape of the orbital.
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ZpzjU4NfAhw-020|In this case, the shape is spherical.
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ZpzjU4NfAhw-021|In that case, the s might be a little bit helpful.
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ZpzjU4NfAhw-022|s spherical l equals 0 is spherical.
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ZpzjU4NfAhw-023|So the 1s orbital is spherical, and I've written this plus sign to indicate there's no nodes.
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ZpzjU4NfAhw-024|The wave function does not change sign.
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ZpzjU4NfAhw-027|And of course, the number of nodes is n minus 1, so 1 minus 1 is 0.
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ZpzjU4NfAhw-028|There's no nodes in the 1s orbital.
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ZpzjU4NfAhw-029|Well, can we go to n equal 2?
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ZpzjU4NfAhw-030|We're done with n equal 1.
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ZpzjU4NfAhw-031|There's no other possibilities of the quantum numbers.
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ZpzjU4NfAhw-032|We go to n equal 2.
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ZpzjU4NfAhw-033|For n equal 2, one possible value of l now is 0.
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ZpzjU4NfAhw-034|So l can be 0 or 1.
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ZpzjU4NfAhw-035|But let's look at the 0 value first.
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ZpzjU4NfAhw-036|So that's s.
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ZpzjU4NfAhw-037|m sub l is still 0.
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ZpzjU4NfAhw-038|So what we have here is another spherically symmetric orbital, but in this case, it's a 2s orbital, but n equals 1.
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ZpzjU4NfAhw-039|So the total number of nodes and minus 1 is 1.
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ZpzjU4NfAhw-042|It had a positive sign in this region, a negative sign in that region.
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ZpzjU4NfAhw-043|The square of the wave function is always positive, but the wave function changed sign, giving you this radial node.
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7Nv8QLeF3yY-000|Let's look at that NO2 to NO3- reaction, and this time think about the oxidation number change.
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7Nv8QLeF3yY-001|So how does the oxidation number of nitrogen change in the transition NO2- to NO3-?
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7Nv8QLeF3yY-010|If we assign the electrons in the bonds to the more electronegative element, this nitrogen has only two electrons around it in a lone pair.
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7Nv8QLeF3yY-014|So in NO2-, it has three fewer than it normally would for a plus 3 oxidation number.
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7Nv8QLeF3yY-015|In this case, NO3-, nitrogen has five fewer electrons than it would as a neutral atom.
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7Nv8QLeF3yY-016|So an oxidation number of plus 5.
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-vJXlNkMqYE-003|Now, this reaction profile doesn't tell us anything about how fast that energy will be released.
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-vJXlNkMqYE-007|But intuitively, we know that time is a parameter that we can look at.
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-vJXlNkMqYE-008|Some reactions go quickly and some go slowly.
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-vJXlNkMqYE-009|Here's a reaction of zinc and acid.
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-vJXlNkMqYE-010|Now, the zinc and acid, same amount of zinc in both of these flasks.
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-vJXlNkMqYE-012|But since there's the same amount of zinc, zinc limits the reaction.
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-vJXlNkMqYE-013|When the zinc is consumed, the reaction is over.
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-vJXlNkMqYE-014|So the same amount of energy is released in both cases.
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-vJXlNkMqYE-017|So this time parameter is the realm of chemical kinetics.
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-vJXlNkMqYE-018|We know that when we mix H2 and O2 together, they can sit there almost indefinitely.
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-vJXlNkMqYE-019|And the reason is the collisions between the hydrogen and the oxygen often don't have sufficient energy to go from products to reactants.
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-vJXlNkMqYE-021|That barrier says you need energy to go from reactants to products.
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-vJXlNkMqYE-023|Everything else being equal-- concentrations, temperatures, pressures.
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-vJXlNkMqYE-025|So you can see along a reaction profile you have two separate domains-- the domain of thermodynamics and the domain of kinetics.
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myr7i1nYj-4-000|Let's do a chem quiz involving isotopes.
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myr7i1nYj-4-003|I'm going to let them react to form oxygen molecules.
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myr7i1nYj-4-011|Our problem was oxygen atoms in a flask.
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myr7i1nYj-4-012|Two different isotopes, oxygen 16, and oxygen 18.
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myr7i1nYj-4-013|They're going to react to form oxygen molecules.
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myr7i1nYj-4-014|So I'll get oxygen molecules with three different masses.
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myr7i1nYj-4-015|If an oxygen 16 reacts with an oxygen 16, that gives me an oxygen molecule of mass 32.
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myr7i1nYj-4-016|If an auction 16 reacts with an auction 18, an oxygen molecule of mass 34.
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myr7i1nYj-4-017|And if an 18 reacts with an 18, an oxygen molecule of mass 36.
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myr7i1nYj-4-018|So what's the distribution of masses?
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myr7i1nYj-4-025|It turns out it's actually twice as likely that you get the 16-18 combination.
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myr7i1nYj-4-026|It's the same thing in this physical example, where I have blue and red chocolate-covered candies.
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myr7i1nYj-4-027|If I mix them together-- equal numbers of each-- and then pick them out at random, what kind of combinations would I get?
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myr7i1nYj-4-028|Well, let's pick out one with each hand.
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myr7i1nYj-4-029|If I reach in and I pick out a blue, and I reach in with the other hand, there's two possible combinations.
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myr7i1nYj-4-030|I could pick out a red, or I could reach in and pick out a blue.
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myr7i1nYj-4-031|But what if this hand first picked out a red?
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myr7i1nYj-4-032|Well, the same thing could occur.
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myr7i1nYj-4-033|I could pick out a blue, or I could pick out a red.
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myr7i1nYj-4-034|So the combination of red-blue, occurred both times, regardless of what was in this hand.
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myr7i1nYj-4-035|It's twice as likely that the red-blue combination occurs, just like in an equimolar mixture of oxygen atoms.
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myr7i1nYj-4-038|And it's always likely that chocolate-covered candies are incredibly delicious.
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ZFZ2J8gwIkE-000|Equilibrium can occur in a variety of situations.
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ZFZ2J8gwIkE-001|A heterogeneous equilibrium would be one between a gas and a liquid, two different phases, or a solid and a liquid.
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ZFZ2J8gwIkE-002|If the phases are different, we call it a heterogeneous equilibrium.
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ZFZ2J8gwIkE-006|If you wait long enough these two values will come to equilibrium, the quotient will stop changing.
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ZFZ2J8gwIkE-007|It will become a constant.
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ZFZ2J8gwIkE-011|When it's sealed, there's a high pressure of carbon dioxide gas.
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ZFZ2J8gwIkE-012|A high pressure because by Le Chatelier's principle that drives the reaction towards the dissolved carbon dioxide.
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ZFZ2J8gwIkE-013|So you can get more carbon dioxide gas dissolved at high pressure.
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ZFZ2J8gwIkE-014|When you open it, you reduce the pressure, lowering the pressure here causes the equilibrium to shift back this way.
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ZFZ2J8gwIkE-015|So aqueous carbon dioxide comes out of solution, and it spontaneously comes out of solution all through the solution.
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