CHEMISTRY COMMUNITY

Shushanna S 3F

E and Z are part of the IUPAC naming guidelines. But they mean the same thing.

Shushanna S 3F

The iron goes from an oxidation state of 0 to +2 (and the oxygen goes from 0 to -2). And since there are two moles of iron and oxygen, 2*2electrons=4 electrons. Hope that helps!

Shushanna S 3F

The iron goes from an oxidation state of 0 to +2 (and the oxygen goes from 0 to -2). And since there are two moles of iron and oxygen, 2*2electrons=4 electrons. Hope that helps!

Shushanna S 3F

I never knew CH₃CH₂CH₃ enjoyed pain.

(Propane... Pro-pain. Ha)

Shushanna S 3F

Sometimes you can guess from the structures of the reactants. For example if one of the reactants is trigonal planar and it is the central atom that is going to be involved in the reaction, then it makes sense that the other reactant will form a bond from either the top or the bottom of that molecul...

Shushanna S 3F

I don't see why that would be a requirement for the reaction...but in the course reader it says that for our purposes of introduction to o-chem, "we will focus mainly on reactions that involve carbon-carbon double bonds"(80).

Shushanna S 3F

Friend texts me: Hey do you think we can hang out?

Me: NOBr, I'm busy.

*starts laughing at own joke*

Shushanna S 3F

Faraday's constant is actually 96,485.3. There's a typo on the back of the laminated periodic table. I checked in our lecture notes for the course reader and it's given as 96,485. (I think the .3 was left off but you can double check.)

Shushanna S 3F

I'm so salty, you could you could make a battery out of me.

Shushanna S 3F

You divide the amount of heat by the number of moles to get 8.22 kJ/mol. This is because the problem tells you that that's the amount of energy it takes to for that amount of moles of methane to vaporize, so all you have to do is put in the the standard kJ per mole notation.

Shushanna S 3F

That makes perfect sense. Thank you.

Shushanna S 3F

The question asks: "How much heat is required to convert a 42.30g block of ice at -5.042 degrees C into water vapor at 150.35 degrees C?" I know that I have to factor in the change in enthalpy due to the two phase changes. I converted the grams of H2O to moles and multipled that to the del...

Shushanna S 3F

A simple way I think about this is: if you're in a box and pushing the roof away from you to make more space, then you (the system) is doing work on the surrounding (because it takes effort to push the roof). If the roof is pushing down on you (even though you resist) the roof (surrounding) is doing...

Shushanna S 3F

What did the crazy chemist do with the bulls at rodeo?

He Rhodium. *ba dum tss*

(thought of this myself tyvm)

Shushanna S 3F

If you're referring to Gas Constant R: "If R=8.206x10^-2 L.atm.K^-1.mol^-1 is used then the answer is in atm and it can be left as atm. If R=8.314x10^-2 L.bar.K^-1.mol^-1 is used then the answer is in bar which is perfect."

This is on page 9 of the Chemical Equilibra course reader notes.

Shushanna S 3F

Some of them you just have to memorize. There should be a table in the book (either in Fundamentals or in this chapter) with a list of strong acids and bases.

Shushanna S 3F

You can figure out by drawing a complete Lewis structure, but since that takes a while--especially for something like diethylenetriamine (it makes three bonds, so it's tridentate), it's better just to memorize the chart of ligands he gave us.

Shushanna S 3F

What kind of dentate a ligand is depends not only on the number of atoms with lone pairs, but also on the geometry. For example, the best structure for a bidentate molecule is the half ring. With the atoms with lone pairs separated by two spacers.

Shushanna S 3F

@Lauren: Nitrogen usually makes 3 bonds and carbon usually makes 4 bonds.

@JELCI: Knowing the number of bonds an atom tends to make helps with the placement of atoms in more complex molecules and is usually a result of the number and arrangement of valence electrons of the atom.

Shushanna S 3F

If I recall correctly, these angles are experimentally determined, so I don't think we can calculate them. Just something we need to know.

Shushanna S 3F

For #19, one thing you need to know is that n (principle quantum number) = shell, l (angular momentum quantum number) = subshell, and that m sub l (the magnetic quantum number)=orbital. You know that m sub l = l, l-1,... -l. Using the value of l, you find the values of m sub l and count how many val...

Shushanna S 3F

@Kevin Tam 1D I tried your method, but got 511nm instead of 397nm (the answer in the back of the book). But I agree with your logic...so I'm puzzled too. @Preston_Dang_1C I also tried your method just for comparison and got 434nm, which once again, isn't the correct answer of 397nm. What are we miss...

Shushanna S 3F

Also, something else Dr. Lavelle said is that we cannot detect anything that is smaller than 10^-15. Usually an electron's wavelength is less than that so we can detect it--unlike the baseball.

Shushanna S 3F

Yeah that's correct.

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