Polyprotic (NB)

INSTRUCTOR: Let’s try to sketch the titration curve for a polyprotic weak acid. So I’ve chosen here histidine. And what I’d like to do is sketch the titration curve for 100 mils of 0.1 molar histidine as it’s titrated with 1 molar sodium hydroxide. And we can also talk about which species are present when […]

Strong Acid-Base Titration

PROFESSOR: Titration is the process of reacting acid and base together. And I do that in a controlled way. So I can take an acid solution and a base. The acid solution will originally have low pH, a high acid concentration. As you add base, that base will react with the acid and lower that […]

Iron Oxide Reaction (Quiz)

PROFESSOR: Let’s look at a reaction with iron oxide that produces molten iron. So, which of the following– carbon, iron, or aluminum– should I react with iron oxide– and I’ll give you a hint, it will be an exchange reaction. The metals will exchange the oxygen– to form molten iron. Think about that for a […]

#06 Biochemistry Protein Purification Lecture for Kevin Ahern’s BB 450/550

Captioning provided by Disability Access Services at Oregon State University. Kevin Ahern: So we’re moving along nicely with the schedule. And though we don’t have to stay on it exactly, we’ve been on it pretty good. I’ve been pleased with the interactions and also pleased with the questions I’m getting, both in class and out […]

#29 Biochemistry Citric Acid Cycle II Lecture for Kevin Ahern’s BB 451/551

Kevin Ahern: This is really bad. I was not fishing for that. The second is some of you have noted that there are some discrepancies between what I talk about with E1, E2, and E3, and what the book says. The book is actually more precise than I am, and I’m trying to simplify this […]

Barking NO CS2 Tube Demo

PROFESSOR: We’re in the demo lab with Lonnie to see a controlled explosion. Lonnie is going to react carbon disulfide and NO gas. The reaction releases a tremendous amount of energy, 3,000 kilojoules per mole. But the kinetics is such that the reaction actually occurs relatively slowly. It’s a complex chemical reaction involving many steps. […]

Practice Problems: Net Charge, Mass Number, Atomic Number

Here’s an atom. What is the atomic number, the mass number and the net charge to this atom? So the atomic number is the number of protons. In this diagram, these little red circles are representing protons here in the nucleus so we’ve got 1, 2, 3, 4, 5 which means my atomic number is […]

Lactic Acid Bond Angle (Quiz)

PROFESSOR: Let’s look at some bond angles in lactic acid. Here’s lactic acid and the carbon, oxygen, hydrogen bond angle is of interest here. Is that 109 degrees, 120 degrees, or 180 degrees? Think about that for a minute and make a selection. Let’s look at possible explanations for each of the answers. A, oxygen […]

Isomers: Stereo (Chiral)

PROFESSOR: There’s another kind of stereo isomerism. If a molecule is intrinsically asymmetric, doesn’t have a plane of symmetry, it’s often the case that that molecule and its mirror image are different molecules. So here’s a molecule. Bring in a mirror plane. Those are reflections of each other. Those molecules are different and I can […]

#12 Biochemistry Catalytic Mechanisms I Lecture for Kevin Ahern’s BB 450/550

Kevin Ahern: Exam prep’s coming along? I’ve got two announcements, well, actually maybe three. So we’ll get everything in order here. First, I do have a review session scheduled. It will be in ALS 4001 on Saturday at 3:00 p.m. I will videotape that. We’re set there. That was number one. I said “three,” didn’t […]