Chemistry Interview

               Below is a transcript from a Decoding interview conducted in the summer of 2023, as part of the Indiana University Decoding Transitions to College Project. The interviewee focused on bottlenecks to learning in a large introductory course on chemistry that she regularly teaches. The primary interviewers were a college English teacher and a high school chemistry teacher. The text of the interview was been lightly edited to make the recorded text more easily readable.

00:00:33 [College English Teacher]

Alright, alright. So tell us about something your students get stuck.

00:00:51 [College Chemistry Teacher]

There are lots of areas where students will get stuck in chemistry and a lot of it can revolve around math and just getting the math right. We talked about that a little bit yesterday, but I want to move beyond that a little bit. When they learn a new part of the puzzle they have a hard time seeing how the pieces fit together. So they might understand one concept pretty well. You introduce a new concept, and they seem to get it. And now you're asking them a kind of a leading question on top of that and then they break down. Even if they did both of the parts individually correctly, they can't see how they fit together. And this is something I think I've been struggling with a while. Because they tend to just want to get to the answer. You'll see this in online homework. . . . the nice thing about online homework, which is amazing is they type in an answer and it will say yes and if it says no, you didn't get it right. We have it so that they can go back, ask questions you know and try again without any penalty. This is awesome, they get feedback. They can see if they're making progress. Some of them will take that time. “Oh, I got this wrong. OK, let's go back and look at my lecture notes. Let's go back to the textbook. Ohh I'm still really stuck let's go back and have office hours.” But other ones will be like, “Hey, Mike, I didn't get this, right.” They wouldn't say “can you explain it to me?” They would just be like “what do you get?” And then be able to derive their answer from that. So they they do things on the quick without getting the big picture grasp of it.

  And so then when they're forced [to deal with] new concepts, they don't see how they are related to what they've already done.

00:02:56 [[COLLEGE ENGLISH TEACHER]]

Mhmm, okay. So when you were starting out as a student of chemistry in the early days. Can you think of an example of a time when you had an initial concept that you mastered. Maybe a second one, but then had trouble integrating them or had trouble bringing one to bear on the other.

00:03:18 [College Chemistry Teacher]

In college I remember learning the concept of molarity. So figuring out the concentration so you're making lemonade and you know you can make it with just a little bit of sugar. It doesn't taste as great or I can increase the concentration by adding more sugar. So like just this idea of you can change its concentration, so we call that molarity. It has different units and just like grams you can talkin terms of moles per liter this is kind of fun.

00:03:59 [[COLLEGE ENGLISH TEACHER]]

This is helpful, thank you.

00:03:59 Speaker 2

OK, so you can talk about how things are more concentrated or less concentrated. And then we [are] introduced to this idea. You have this stock solution that is more concentrated, you need to make a solution. And so you can use this fancy formula. M1V1 equals M2V2. OK, they can get that memorized really quickly. M stands for Molarity, V stands for volume and you have one and two, the initial and the in the diluted. I remember as a student I got it. I can plug in numbers. I can solve and figure out the new concentration. OK, so then as a college student, I have already finished this class and checked that box off. I was doing undergrad research, and my professor [says] “Go get a solution. I don't remember what it was. So let's just say salt, sodium chloride. Go make a .5 molar sodium chloride solution. We need about 200 mils. I remember being like “Listen, the math should have been really easy.” But I think him just saying “go make it” was out of context. I did the math before, I understand concentration. But to then to have to go do it and solve and put those pieces together was difficult.

00:05:26 [[COLLEGE ENGLISH TEACHER]]

Mhmm. And so it wasn't about the math, right? The math wasn't intimidating you. It was the sort of the process, of translating that math into a practice that was daunting.

00:05:41 [College Chemistry Teacher]

Yeah, I think we see this with students when they get into the lab for the first time ever. It's a little overwhelming. You know you just don't know your way around. You don't want to mess anything up. You don't want to break anything. . . .  I should have really understood this concept and he's asking me to do this like. Yeah, yeah. So, it was just a little, probably a little intimidation and not being sure of my surroundings.

00:06:12 [College English Teacher]

Right and so how did you figure it out?

00:06:15 [College Chemistry Teacher]

I probably found another student.

Fellows

Laughing.

00:06:18 [College Chemistry Teacher]

Hmm this is what I would do. There was a girl named Julia that was working in the lab with me. That reassurance is a really helpful piece and and I try to remember that with my students . . . [II tell them to] talk to the person next to you because .. . [if], we both got the same answer that we probably are on the right track. . . .

00:06:55 [College English Teacher]

So, if you were in an analogous situation now which would be, of course completely different because you understand how concentration works. . . . Knowing what you know now or having sort of become a chemist, how what would you do differently about to work the problem?

00:07:20 [College Chemistry Teacher]

I think I would have sat and just taken some time. I think it would be this problem solving strategy of “OK, here's what I need. OK, I know this about molarity.  I know this calculation. OK. This is the piece I don't know. And then trying to just sit and be OK being uncomfortable with that, to get to the answer.

00:07:44 [College English Teacher]

Mhm. OK so and so that's a few things you identify what you need in order to move to the next step. You identify what you don't know or don't know the kind of variable in question that you need to resolve, right?

00:08:07  [High School Chemistry Teacher]

You're self aware. Self aware of of what you have with your deficiencies and your strengths as well.

00:08:23 [College Chemistry Teacher]

And I think that is such a helpful thing for the students. I'm sure other subjects have this too. But in chemistry we do a lot: “Hey, we're going to teach you this.” And then the next class: you know what you learned? That wasn't all the way correct. There's a little bit better understanding how we think about bonding.” I remember getting so pissed off about like working so hard to understand the core model and then it actually didn't work just for hydrogen with one electron. And I’m like then “What the heck did you tell us this for.”

And I think that's where they get it wrong. They don't see [that] this is important to show you where they started, to see how it builds, but the big picture idea is what you need to hold on to. And I think sometimes students get so caught in the little details of what this electron is doing?

[College English Teacher]

I have two questions. I mean in this procedure that you would have identifying what you do and don't know and calming your nerves about uncertainty and [have to] be able to think through that. Are there sort of concrete tactical steps that you follow? Like do you draw a picture or do you make a list of knowns and unknowns. Do you try to write it, translate something into an equation, or translate it into words? What are the strategies like?

00:10:33 [College Chemistry Teacher]

I have so many strategies at this point that I am sharing with students, and sometimes maybe too many things. And they go like (motions over her head] So there's so many things I incorporate now into my teaching because I remember, this was tricky for me. You know, like silly things. Like orbitals and something orbiting like or when they did hybridized orbitals and they call them SP3, why did they call them what the atomic orbitals were the S and the P like why they put those together, like I never understood the picture of these, atomic orbitals are coming together to make this Molecular orbital. That's why they named them that way so you can see which atomic orbitals came together. But for me it was just like why didn’t they, you know, orange pink. You know, like something totally unrelated to the SP or like why is it, you know? So now that I know that that was tricky for me I can really hit that for the students like this is kind of weird like why did they name these? You know, electron cloud groups like this and that type of stuff. So when I'm teaching I will throw out lots of these hints and things. Like one suggestion I have for them is if you think you're pretty good and confident [about the] material go back to the book and look at just the images and the graphs. If you can look at it and sit and explain what's going on in that image or the significance of this, you know the data that's being showed. Hey, you have a good grasp of that concept. You don't have to read the whole thing. When they're going through the lecture notes, oh the teachers teaching it makes so much sense when we work on the problem together. Of course it does cause I'm asking you the leading questions  I know how to get you to lead me to that answer. But you try it on your own and you're lost.

OK. So, what do we do first? And I have gotten to that point where I'm pretty good at at sharing those details. I'll start with telling them what we haven't learned yet. It's something I make the students say out loud and repeat after me, . . . I haven't learned that. That's OK because there's lots of things that you don't know yet. . . . So, I do a lot of intro teaching about being OK with being stuck, but what are you going to do? And I think the ones that want to rush and just check [off] “Got my mastering chemistry done, got my homework done” --  when they get the new little-bit-more-difficult questions especially that incorporate multiple content areas, they fail. I've been giving this advice all throughout, like the best studying tips you have to repeatedly practice. Test yourself, identify spots in your notes and then go back to it. And I can give them that, but there's still, a few students that struggle and try and come to office hours. Where is it in their brain that they are hitting a roadblock?

00:13:52 [College English Teacher]

Do you think it's emotion? I guess I'm trying to isolate whether you understand it as kind of emotional response like panic. It's like they have the two concepts they don't immediately see how to apply one to the other or how they integrate, and then they panic and shut down or rush or something?

[College Chemistry Teacher]

Yes.

[College English Teacher]

That kind of sounds like an emotional bottleneck as much as an intellectual one.

00:14:24 [College Chemistry Teacher]

And they doubt themselves.

[College English Teacher]

Right.

[College Chemistry Teacher]

You'll see them second guessing things. Not confident and then trying something new and getting it wrong.

Yeah, there is some of that.

00:14:37 [College English Teacher]

I assume that you say you're being explicit about this, right, like you talk about it.

[College Chemistry Teacher]

Yes.

[College English Teacher]

I mean, it seems like obviously an important first step. But then trying to sort out, once one calms one’s nerves . . .  If I'm a student. So OK, so first of all, hey, I'm panicked, but I've been told that I shouldn't panic, right? So I'm gonna panic and so how do I work the problem right? What do I do? What is the next step? Is there a kind of order of operation. Is it an abstract enough scale that it can apply to different problems.

00:15:15 [College Chemistry Teacher]

I think so. I had printed out a couple of problems from an exam. There are two different topics. Just looking at both of them, you might just look at the numbers. So one just gives you a reaction and tells you the enthalpy change. OK, so the reaction will be changed and then it says, “How much of the reactant do you need in order to give this much heat?” So there's a lot of like enthalpy, heat, OK, you might not know those that are related terms. You have to put together the fact that this balance equation gives you the enthalpy in kilojoules per two moles of the hydrogen gas because that's how the balance equation works. You have to figure out how the enthalpy fits with this balanced equation. And then you have to kind of figure out “OK well I need to make this much heat, how many grams? Well, I can figure out the whole part?” So, there's a lot of little pieces where, if a student has no clue on this problem, they're given just really 2 numbers. And they're in heat OK, so in kilojoules. So the amount of energy, and this is in grams. Howdo you go from kilojoules to grams? That's not an easy connection initially to make.

Now actually the math there is really pretty simple. But you have to identify what the conversion factor is. So, the math is the easy part I don't think any student would have trouble with that. But they have to pull up the conversion factor themselves and it's not super clear sometimes if they're not comfortable, but for every two moles of hydrogen, you'll produce this much heat. And you can see there's a negative number in front of that that means that heat is given off so this reaction would feel hot to the touch. So this is a combustion reaction So something's giving off energy. This is the amount of heat that's given off every one mole of oxygen.

And if you notice I said two moles here and I said one mole there. What would I say for this one? I would say for every two moles of water produced it gives me this much heat. So I'm learning how to use this balance equation relating the reactants and products and that number in front, which we call coefficient to figure out how much heat is produced. Well, if I can say that there's two moles for this much heat, but I want to get this much heat. Well, I know it's going to be less than two moles, right? Because two moles will give me this. So, I can go back and now figure out Oh, that's my conversion factor. I'm going to start with this number right here.” And that's where they might not know where to start and I can work my way and set up the problem pretty easily to get the right answer.

That was hard for students, right? They should have understood balance equations combustion at this point we just introduced the enthalpy we did several problems practicing reading that correctly and then I did a problem in class where I started with the mass and had them work to this number. So, I knew this problem was going to be tricky because I wanted to test can I do it the other way? Can I say I want to produce this much heat. So, I knew you know when you're building these exams you can't put every question at a level one question, right? You have to have some that are stretching. If everyone gets the answer, that's ideal, but you have to have somewhere [that] separates out students that really get it and student that kind of half to get it, but not all the way, OK. So this was a stretch question for sure.

00:19:07 [College English Teacher]

If the student is bewildered by this question, what I mean, what is it that they need to do first, that they might not do first that would mess them up? I'm thinking about the order of operations.

[College Chemistry Teacher]

Yeah.

[College English Teacher]

So, you know, they have to determine the conversion factor that's like.

00:19:24 [College Chemistry Teacher]

Like, that's the first one and I think that's where most of them got stuck.

00:19:31 [College English Teacher]

When I hear the term, the conversion factor, is that a multi stage process? Or is it something that you can look up?  It's understanding how it could be much more complicated thing.

00:19:50 [College Chemistry Teacher]

You are doing a good job at asking questions.

00:19:51 [College English Teacher]

But yeah, so the term in the conversion factor is that a multi-step process?

00:20:01 [College Chemistry Teacher]

It could be.  This equation could have been harder. I expect students to know a combustion reaction so I could have said right the reaction went hydrogen and oxygen combust. I could have then, then they would have to write the formulas, they'd have to write the correct reaction products. Then they would have to write the balance equation. So, it could be even a bit harder. I didn't want to test [whether] they could write balance equations at this point. I was just testing about this knowledge. So yeah, this could be more complicated and harder. But given the balanced equations already, the tricky thing was -- of course, I picked hydrogen because I wanted to pick something that was a 2 instead of just a 1. And when there's no number written in front, it's just assumed that it's a one. So, the fact that there's nothing in front of the oxygen.

00:20:49 [College English Teacher]

When we talk about balance equations, I want to look at the equal sign it both sides of the equal sign. But it seems like I don't know what the arrow is.

[Inaudible comments by the high schoolchemistry teacher]

00:21:33 [College Chemistry Teacher]

And that's where they can get confused for sure. Yeah, that triangle what the heck does that stand for? And H and K? You know, like, yeah, there's a ton of terminology.

[In an interview with a high school chemistry teacher yesterday]  I think one of the things that David might have asked was “Do they know that this is pressure or something that they were trying to solve for I don't remember exactly.” But I remember thinking that's a good point because my students will sometimes --  you know with gas laws, there's you have a pressure, a volume, the amount of the material so moles is how we talk about it, temperature, and then a gas acid. So there's these five pieces that you need a constant so that's usually given. And then you need to know three of the four, and you could solve for the 4th one. And sometimes when you're given them, they're not in the right units, OK. And so you have to do some converting to get to that unit. But sometimes the student might be given one and it's got the terminology like millimeters of mercury or atmospheres, and they might not know that one stands for the unit of the pressure. That's even hard for them. To then pull it all together.

So it is a lot and you can see how it builds on itself and they're held accountable as the problems get harder. The math again for the next problem isn't terrible. 27% of students got this correct. There was a problem, this was an easier version of a problem they had on a on a homework already. But I made the math easier for that one.

00:23:42 [High School Chemistry Teacher]

It would just be so nice. to know from their perspective There's multiple things that could touch them. Where did they go wrong in any number of ways. I mean they could not have attended classes. They could not be, they could not be paying attention if they are there. They could not have done with these particular homework problems. They could have help from a friend when they did those problems. They're not able to do that on their own. They could understand everything but one piece of it.

00:24:14 [College Chemistry Teacher]

And especially multiple choice. One girl on the student work that I showed, they worked through these once they got wrong doing a problem solving thing. One girl said she did all of it right and got to moles. But she didn't do the last easy conversion to go to grams. You know, and that's frustrating when it's a problem worth 4 points or whatever to do. You had the process right, like she was like oh she got it. She only missed one little part, whereas other students just looked at it and couldn't figure out how this and this related.

00:24:48 [High School Chemistry Teacher]

So I guess what I was thinking is working with some and allowing yourself to be empowered to work with the subset of people that would come and seek help. So, let's narrow down the path. Because that's what you said was on your part of the question. So when people come to office hours just maybe ask them to self-report, where do you get stuck with a problem like this? And then that helps you go through that get to that breakthrough if they say I have no idea what began. Which they might say.

[College Chemistry Teacher]

Yes.

[High School Chemistry Teacher]

You know then if you tease that apart like, well, what where in this can we go? And it could be they have no idea. But then to help them go back to their notes maybe or to say who did this, but I wasn't paying attention or I didn't know. You go back and so this is oh, this is that kind of problem.

00:25:44 [College Chemistry Teacher]

Yeah, so at the end of last semester, we have a teaching and Learning Center and they have you know, I don't know if you ever go to any of their their stuff, but they hold talks and they bring people in and they brought this lady in, Josie Navardo, I think I wrote her name down there. She's gonna be teaching at Ohio State in the Fall. She shared this problem solving template. And this is what I try to do teaching wise. Asking leading questions when we're in front, but sometimes having them do it on their own because yes, in office hours I can do it, except I am realizing my office hours are getting so packed that a lot of times I'm running around I'm like, OK, here's who your next. You know like it's less of me being able to lead you and more of me like I got five more kids raising their hand. You know like so it's this time issue like OK, where are you gonna go? Ohh yeah alright check back with me once you get that you. So it's less being able to sit.

So this problem solving worksheet does a lot and I really am going to start, so I did it one time because I figured it out I saw it at the end of the semester. So, I used it one time it was great and but it was very tedious and that it broke the problem down for students. So I used it as a problem they got wrong on this exam and then I made them work through this worksheet. Identify what's given, identify what concepts, big concepts, what equations or what other information do you need? Where have you seen this problem before? And that's where they lack clarity and big picture , cause there's nothing on my exams that they haven't seen. They don't see that. But I can show you exactly where we've tested this stuff and and again, the concepts I did trick, you know not trick them. But I did change it a little bit cause I don't wanna just be able to regurgitate everything I've done I wanted to be able to apply it and think big picture a little bit more. So I like that question because we're like, Oh yeah, we did do that in class. Oh yeah, that was on a practice exam worksheet.

00:27:49 [David Pace]

Can I throw out a question? Because you're talking about this you you kind of dealt with this question and I would like to hear more about it. Something about recognizing what kind of a problem it is.

00:28:03 [College Chemistry Teacher]

Um, you would do that from the wording. Sometimes it says. Like if you're given a balance equation, you're gonna often be asked about reactants or products. So it could be a stoichiometry. Or if you're just told about reactants, you know that you maybe need to predict the products and balance equation. So you have to you know.

00:28:21 [DP]

How do you actually do that? Do you look for certain there's certain words that suggest? Are there certain kind of . . .  what do you look for to tell you this is this kind of question.

00:28:32 [College Chemistry Teacher]

I guess I would look at what numbers are given. Like what number and what unit is there. And even if you don't know the big picture, a lot of times and that's why you have students that are good with math that can handle you know, intro Chem because I don't remember the equation, but I know how to make these units, if they're good with their dimensional analysis, they can solve for units. They don't have to understand what they did they just know I got my units to cancel I got the right answer.  And I want to move them beyond that, of course. Because they'll get stuck when they get to organic chemistry, where you really have to see big picture and they can't work it around with units. So again, just identify like “Oh you don't have to have the full answer yet. But this is where I'm starting and if they can find where they're trying to go. Those two pieces really help them. And they're like, OK well where what can lead to this, you know, like oh if we're doing a dimensional analysis. Oh, if I can use this density or this concentration as conversion factor. OK then I can go from grams to volume. You know that type of thing or you can use a lot of reverse engineering and chemistry and that's why students that are excellent in math tend to excel even if they don't understand the big picture.

00:29:48 [DP]

I'm presuming also ideally you want them to be able to access “we've covered these topics in the course, of course, and now I need to go back to that part of my brain where week 3 we covered this.”

[College Chemistry Teacher]

Yeah.

[DP]

And how did they know it's week 3 and week 4?

00:30:05 [College Chemistry Teacher]

I don't think they even need to know that

[DP]

OK.

00:30:07 [College Chemistry Teacher]

I don't think they need to know which week it was.

00:30:09 Fellows

Inaudible

00:30:12 [DP]

Body of material.

00:30:16 [College Chemistry Teacher]

It builds a ton. I would say it's constantly building on itself if it's set up properly. And I try to do a lot of like asking why is this important? What is the big picture that we're trying to reach?

00:30:30 [DP]

Let me make sure that I understand that. In many fields, they'll be you'll learn this kind of thing and the particular problem only addresseer part B. But you seem to be saying that  that somehow this is an organic polar material and so you are addressing everything you've learned is that what you're saying?

00:30:49 [College Chemistry Teacher]

Yeah, it definitely builds. You have to understand electrons and what makes up an atom before you can think about valence electrons, you have to have a little bit of idea about a periodic table before you can look at that. And then [another chemistry fellow in the program] was talking about making dot structures, Lewis structure. You need to know that before you can talk about the shape of a molecule, because the type of bonds and the arrangement of the bonds plays affect into that. Well and then once you know the shape of the molecule, you can then figure out it's polarity. OK, so it does it have a partial positive side to the molecule and a partial negative side. Because if it's a polar molecule, it will interact differently than non-polar that affects its melting point. That affects how it you know, will evaporate, so water is polar that has a partial negative and a partial positive. Which makes it have a very high boiling point compared to other things.

00:31:53 [College English Teacher]

This is very, yeah, well, you're doing this moment is, you know, it's clear. Yeah, you sort of unpacking the abreacted nature. You know these things are all kind of building on each other and become an extricable in ways that become clearer, clearer, the more you progress. Yeah, I mean that's becoming very clear, yeah. Even though I don't understand all the details about it right

[Recording ends]