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Nerd_Bunny wrote:How is everyone studying for physical properties? Since this topic hasn't been in rotation for a while I'm having trouble finding any resources to help study.

This subtopic really has me thrown. Like, are we going as far as Ksp for solubility, or is it B division-grade conductivity measurements, for example? It's so hard to get a read for what they're going for with this when B division goes introductory high school while this event doesn't want to go AP level.

I was trying to do slowpoke's SSS chem lab test, and I don't know how to do 2c of the thermodynamics open response. Can someone explain it for me? It says to calculate the standard enthalpy of formation for liquid benzene, given _dH(f) for gaseous benzene is 82.9 kJ/mol.

Other givens are: dS for vaporization of benzene is -90.91 J/(mol*K), enthalpy of vaporization is -32.11 kJ/mol, its boiling point is 353.2 K, and exhibits a vapor pressure of .526 atm at 333.6 K.

Thanks so much!

Nerd_bunny wrote:How is everyone studying for physical properties? Since this topic hasn't been in rotation for a while I'm having trouble finding any resources to help study.

As a test writer, I focused more on the concepts behind the physical properties than on the properties themselves. For instance, I tested the ideas behind say, why some things are denser than others or how dissolving things in water works. The only issues is that while that approach works well for like conductivity (you need to understand intermolecular forces), things like color require pulling material from organic or even undergrad level inorganic chemistry. Magnetism and solubility are also super vague. It's pretty hard to figure out how far as a test writer you're supposed to go, or what SciOly intended exactly with their rules.

The questions I attempted to avoid were memorization problems. For instance, I wouldn't put a "Order the density of these metals" thing on the exam because 1) it requires you to dedicate a not insignificant space to record information that doesn't really help you progress as a chemist and 2) it's better to test say, the reasons why some metals are denser (ie: they have a more highly packed structure).

All in all, I dislike this topic somewhat intensely. It's hard to find a physical properties lab that doesn't take over 50 minutes or require extensive equipment and preparation. I have not seen a single competition that did not do a thermo lab, and I'm sure that when I do, it will be a highly janky lab. Also, the list of properties feels super arbitrary. Why elasticity, but not hardness? Does elasticity include ductility and malleability also? This topic could have been my favorite if it were more specific, but it's way too vague.

Tl;dr: focus on causes of physical properties and understanding what those properties exactly are.

This is my first year doing science Olympiad and I cannot fully understand the wiki for Chem Lab, my event is this Saturday, are there any things I should add to my sheet that people tend to forget?

Are there any good resources/links to prepare for the Lab portion of this event?

Does anyone know what reference sheets the test proctors will give to us test-takers? For example, will a Periodic Table be provided at the test?

geniusjohn5 wrote:Does anyone know what reference sheets the test proctors will give to us test-takers? For example, will a Periodic Table be provided at the test?

Proctors are supposed to provide all constants, which would include a periodic table (or at least relevant molar masses)

Most tests I have seen do provide these, but sometimes they don't. If you have extra space on your cheat sheet, I would highly recommend adding a periodic table, a list of common enthalpies of formation and specific heats, and other important constants in case the ES doesn't read the rules carefully enough.

Chem Lab is allowed to have 5 pages for cheat sheets, but I have no idea how to fill up all the space.
Did anyone completely fill theirs, or does anyone have any ideas for what to add?

huppada wrote:Chem Lab is allowed to have 5 pages for cheat sheets, but I have no idea how to fill up all the space.
Did anyone completely fill theirs, or does anyone have any ideas for what to add?

Lists of enthalpies, entropies, Gibbs energies, colors

Common constants (ex: anything to do with water)

If you can fit it onto 2 sheets you can make a copy for you and your partner.

I do agree that 5 is overkill for Chem Lab

kenniky wrote:

huppada wrote:Chem Lab is allowed to have 5 pages for cheat sheets, but I have no idea how to fill up all the space.
Did anyone completely fill theirs, or does anyone have any ideas for what to add?

Lists of enthalpies, entropies, Gibbs energies, colors

Common constants (ex: anything to do with water)

If you can fit it onto 2 sheets you can make a copy for you and your partner.

I do agree that 5 is overkill for Chem Lab

My partner and I are completely taking advantage of those 5 sheets. Anything we come across, we put on the sheet. We have pretty large font yet still have tons of room.We're also both doing A&P, so we know how much extra sheets can help. I'd recommend adding as many images, charts, and flowcharts as possible. We have an electron configuration chart, (two actually) a phase diagram, an electronegativity chart, and room for a full periodic table. Don't forget to put some common densities and specific heat values on there too. Event supervisors are supposed to give you these values but sometimes they don't. Really take advantage of those 5 pages.