Chemistry lectures and "How to" videos from a university professor and Ph.D. chemist. I live stream office hours every week on Twitch where I discuss the latest news in climate change, space travel, and the intersection of science and politics. Come join the Melko Lab and learn by osmosis!
Rate units are M/s (also can right as Ms-1) = k(rate constant which we are trying to find)and concentration M but it is M2 because we square A,so unit also get squared, so K=Ms-1/M2 therefore k=M-1s-1
EDIT from previous comment (yt wouldnt let me) :what I meant by tons of pop-ups I meant only when you first go to the website after you start playing the movie you’re NOT gonna get tons of pop-ups interrupting the movie
Technically electrons aren't particles in a certain fixed space. They are "mostly" in one place or another, but we can't be certain and we can only speak in probabilities. Lewis dot structures are simple representations based on where the electrons are most likely to be, but they are indeed playing musical chairs at all times!
You can only tell the "difference in energies" between the levels (or sublevels more precisely). But it is often the case that it ends up in the lowest energy level, so you can sort of piece together what level it started in based on the light color and difference in energy.
When we energize the electrons and make them jump energy level, what happens to their spin? Do they have a preferred order of suborbital to jump to? What is the higher level is full? Do they collide with the other electrons in the higher level? What happens with the electrons left behind?
They usually maintain their same spin. They also tend to change their orbital by one letter, so s to p, or p to d. But they can only go to open spots, so not if a level or sublevel is full. They don't really collide as they are not really particles, but they do interact.
We need more complicated physics to answer this, but basically the energy levels and sublevels are allowed configurations of electrons in quantum mechanics. And the electrons themselves are these weird spread-out wave things, so not technically correct to say they are always closer or further from the nucleus. This sublevel ordering is the correct order of the "most likely" energies of the electrons at any given point.
Why is carbon 12 chosen for atomic mass unit? I understand it has 6 protons, neutrons and electrons respectively and if we divide the mass by 6 then we will get the mass of 1 proton, neutron and electron but think if we use this unit to measure hydrogen atom it would be way off as the hydrogen atom has no neutrons.
Subatomic particles don't have perfectly whole numbers for their mass. In fact, some mass is instead energy holding the nucleus together (like E=mc^2 mass is energy!). So because an atom has a funky mass and a realllllly small number, we pick one element as a standard and round to a whole number. So since carbon is the basis of life and is common, we picked that one. So we say carbon weighs 12 atomic mass units and measure everything relative to that. Hydrogen has no neutrons, but that's really what makes it bad to base things off of, since neutrons have slightly different mass than protons.
It still really, REALLY seems as if the overwhelming majority of people don't care about facts. People just believe whatever they want to believe, or whatever they already believe, and the facts of the matter are completely irrelevant. If they ever change their minds, they do it for their own largely BS reasons. How else to explain why SO MANY people believe ridiculous, false things? Persuasion just seems to go nowhere. I can't think of a single example of a person unironically saying "you know what, you've convinced me, I was wrong."
In a bimolecular elementary Reaction When the concentration of one of the reactants is in large excess compared to the other, the rate of the reaction becomes independent of the concentration of that reactant. Is this statement true or false,could you explain
Yes this is basically true. Imagine you are making sandwiches and that you have 1,000 slices of bread spread on the counter but only 10 slices of cheese somewhere on the counter. The rate at which you can make sandwiches is really only determined by your ability to find the cheese, because there is bread readily available everywhere (it is in large excess).
Hello ! Loved the video as a physics undergrad ! any reason to why in Modified Morse Potential, we can subtract or add De as any arbitrary constant ? from wikipedia on morse potential , I find : "Since the zero of potential energy is arbitrary, the equation for the Morse potential can be rewritten any number of ways by adding or subtracting a constant value." Then proceeded to subtract De from the main equation. I have tried reading the theory from multiple textbooks but I cannot understand why we can do this. Also isnt morse potential a true potential function but rather an approximation of taylor expansion
Where you set the zero of energy does not matter. Because energy is always about relative values. For example, the energy stored in a bond is relative to the energies of the separated atoms. Adding or subtracting a constant simply moves the potential up or down on the energy scale, but does not change the relative energy values (for example the difference in energy from asymptote to the bottom of the potential), which is what's important
one of the biggest frustrations of my undergrad education was learning one thing one semester and being told two or three semesters later...yeah not so much, that was "hand wavy".... three reactions, redox acid base and precip
@@ProfMelko The lightning that will strike you is still doing push ups🤣😂 LOL...Ill read other books but seriously please make more videos, you are really gifted, you know how to teach and im watching your videos from Zimbabwe!😇
Hi, in the last problem of the video, in the equation i might consider rate of the hydrogen, example: -d[o2]/ dt - 1/2 d[h2]/dt = 1/2 d[h2O]/dt? or not?
Yes you may write an expression in terms of H2: -1/2 d[H2]/dt = 1/2 d[H2O]/dt However, since the problem is providing you a rate for O2, it makes more sense to write the rate expression in terms of O2 and go from there.
