CHEMISTRY COMMUNITY

Jordan Tatang 3L

kJ/mol!

Jordan Tatang 3L

Catalysts are not used up in the reaction

Jordan Tatang 3L

i really enjoyed community

Jordan Tatang 3L

for irreversible expansion!

Jordan Tatang 3L

Delta U = 0 in isothermal reactions because the temperature stays the same so q and w cancel each other out.

Jordan Tatang 3L

we add platinum because we need a solid metal to capture the electricity and the common one used is platinum.

Jordan Tatang 3L

if we put the concentrations to the power of 0 we get 1 so we're left with k. As everyone else says, that means that the rate law is independent of the concentration of the reactants.

Jordan Tatang 3L

electrochemistry!

Jordan Tatang 3L

since we didn't really go over them in lecture I doubt they'd show up on the final.

Jordan Tatang 3L

it comes from the ln(2)!

Jordan Tatang 3L

the moles (n) for this equation are the number of electrons transferred in the particular reaction.

Jordan Tatang 3L

We don't multiply the E value by the multiplier of the half reaction because it is an intensive property.

Jordan Tatang 3L

noodles lol

Jordan Tatang 3L

I believe you should be using temp in Kelvin if using 8.341 for R constant.

Jordan Tatang 3L

I use oilrig as well. (oxidation is loss and reduction is gain)

Jordan Tatang 3L

yup a dead battery has an E potential of 0 as well as a G of 0

Jordan Tatang 3L

e^ln k cancels out the natural log and you're left with k.

Jordan Tatang 3L

at constant pressure q = delta h
since
delta u = q + w
at constant pressure
delta u = delta h + w

Jordan Tatang 3L

You can use either one depending on the information provided in the problem.

Jordan Tatang 3L

No, you want to look at the units and make sure that the gas constant you are using applies to the corresponding units.

Jordan Tatang 3L

So we can think of it in terms of Gibbs Free Energy. Since the formula is delta g = delta h — T (delta s) if delta H is positive, then the value of delta s x temperature must be greater than delta h if the reaction is spontaneous.

Jordan Tatang 3L

Yeah, so you could use the delta S = nRln(P1/P2) and plug in the values that were given in the problem.

Jordan Tatang 3L

s of vaporization = enthalpy of vaporization / temperature (K)

Jordan Tatang 3L

Attack on Titan

Jordan Tatang 3L

K is the temperature in Kelvin, but like the others said temperature can change K it just depends on whether the reaction is endothermic or exothermic.

Jordan Tatang 3L

Yes because entropy is a state property is well and that means that they can be added.

Jordan Tatang 3L

Yeah so if you converted to atm you should be using 8.206 x 10^-2. If you conver those atm to bars you would be able to use 8.314

Jordan Tatang 3L

Make sure you look at the units that are provided in the problem and use the Gas Constant that would cancel those units.

Jordan Tatang 3L

Yeah, so there are a lot of responses to this question but it really just depends on the units that are given to you in the question and you would the R gas constant that cancels out those units.

Jordan Tatang 3L

i like sitting down and listening to a podcast.

Jordan Tatang 3L

It depends on what units are given on the problem and you can work based off of that.

Jordan Tatang 3L

you should look at the units that are given in the problem and work based off of that

Jordan Tatang 3L

a lowercase w for work.

Jordan Tatang 3L

a larger negative means there is more work being done

Jordan Tatang 3L

Neutralization is a reaction between an acid and a base and the products are H20 and a salt

Jordan Tatang 3L

Kelvin

Jordan Tatang 3L

If something requires heat such as melting a solid into a liquid then that would be endothermic.

Jordan Tatang 3L

A mneumonic that one of the UA mentioned was
SO I Brought NO Clean ClOthes which corresponds to the strong acids
H2SO4, HI, HBr, HNO3, HCl, HClO3 and HClO4

Jordan Tatang 3L

if a reaction is endothermic which requires heat, adding heat will cause it to perform the forward reaction which favors products. if a reaction is exothermic which releases heat, adding heat will cause it to perform the reverse reaction which favors reactants. The opposite could be said for each if...

Jordan Tatang 3L

I would do it every time if it's around 1.0 x 10^-4 just to be safe.

Jordan Tatang 3L

when the equilibrium constant is less than 1.0 x 10^-4. you can verify if the approximation is valid by finding the percent ionized and if it is less than 5% than the approximation is valid.

Jordan Tatang 3L

like the others said the two terms are synonymous

Jordan Tatang 3L

yup, you're releasing heat, and more heat is released from vapor to liquid than from liquid

Jordan Tatang 3L

I believe we're taking them at our scheduled lecture times.

Jordan Tatang 3L

log rules tell us that log ab is the same as log + log b

Jordan Tatang 3L

like the others said Ka is the equilibrium constant for acids and Kb is the equilibrium constant for bases

Jordan Tatang 3L

Q is the reaction ratio at any point while K is at equilibrium and I think the easiest way is to compare Q and see if it's smaller or larger than K rather than memorizing it.

Jordan Tatang 3L

The coefficient is what you raise the concentration to the power of.

Jordan Tatang 3L

I think you usually use ICE tables when you are given the intial concentrations/partial pressures and only some or none of the equilibriums.

Jordan Tatang 3L

Yup + is endothermic and - is exothermic

Jordan Tatang 3L

As a general rule don't include solids and/or liquids.

Jordan Tatang 3L

just reiterating what everyone else already said Q is at any point in the reaction and K is when the reaction is known to be at equilibrium

Jordan Tatang 3L

yeah as all the others said you would use Kc for concentration and Kp for pressure

Jordan Tatang 3L

I believe the general rule is to not include solids and liquids in the calculation of K

Jordan Tatang 3L

I think the question is going to be specifically asking for it

Jordan Tatang 3L

yup M is molarity which is mol/L

Jordan Tatang 3L

I'm planning on just reading and binging tv shows.

Jordan Tatang 3L

I think just looking through lecture notes and reviewing some textbook questions would be helpful.

Jordan Tatang 3L

For that one, you would look at the product and HClO would be stronger because Cl has a greater electronegativity than I so it stabilizes more efficiently.

Jordan Tatang 3L

The work function is how much energy is required to remove an electron. The threshold frequency is the frequency of the work function which can be calculated using the
E = hv formula.

Jordan Tatang 3L

I believe that the for the question the two mean the same thing.

Jordan Tatang 3L

I think the answer to your question is that it does have to be higher because otherwise the acid would not be able to give off a proton.

Jordan Tatang 3L

I had that problem too and resetting my computer helped me.

Jordan Tatang 3L

Yes, I believe we should be familiar with those

Jordan Tatang 3L

I usually draw the dipole moments to see if they cancel or not.

Jordan Tatang 3L

One trick you could use would just be to count the number of bonds and think about the hybridization that allows for the same number of bonds. i.e. sp^2 has 3 bonds and sp^3 has 4 bonds.

Jordan Tatang 3L

Like the others said I believe you can use either one.

Jordan Tatang 3L

I am wondering this too.

Jordan Tatang 3L

Yeah like the others said the midterms might be during lecture time so just try not to schedule another lecture for the same time.

Jordan Tatang 3L

Yeah, any nonmetal in the third row and beyond.

Jordan Tatang 3L

I believe it's the same this week.

Jordan Tatang 3L

Yeah, like the others said the empirical formula is the lowest ratio so anything smaller would have to be decimals and not whole numbers which isn't allowed.

Jordan Tatang 3L

The 60 degree bond is located between the 3 carbons in the triangle that they create.

Jordan Tatang 3L

Yeah like the others said when you have a resonance structure there are delocalized pi bonds present.

Jordan Tatang 3L

I think for the most part molecules with ionic bonds are going to have much higher boiling points because ionic bonds are a lot stronger.

Jordan Tatang 3L

I think that question also asks for molecular shape if you scroll down.

Jordan Tatang 3L

I agree with what the others said and I wanted to add that Helium is the element with the highest ionization energy so it does follow the trend for that.

Jordan Tatang 3L

I think it's that elements with smaller atomic radii make shorter/stronger bonds because there is less distance between them?

Jordan Tatang 3L

Yes, the f subshell is part of the 4th shell level but like the person above said, it isn't used until you get to an element in the 6th period.

Jordan Tatang 3L

I just wanted to add that oxygen is an exception to the ionization energy trend because the electron-electron repulsion in the first p orbital makes it easier to lose an electron than nitrogen.

Jordan Tatang 3L

I think that although Cl is a halogen it will have a slightly lower electronegativity than O because it is one period lower. It might be due to the lower amount of electron shielding in O which allows it to have slightly stronger pulling power.

Jordan Tatang 3L

Yup! Like Alen said the VSEPR model shows you if the molecule is symmetrical or asymmetrical and therefore non-polar or polar, respectively.

Jordan Tatang 3L

Yup! Like Alen said the VSEPR model shows you if the molecule is symmetrical or asymmetrical and therefore non-polar or polar, respectively.

Jordan Tatang 3L

like the others said, polarizability refers to how easily the electrons in an atom are distorted while polarizing power refers to an atom's ability to distort the electrons in other atoms.

Jordan Tatang 3L

Adding on to that I think the only time when valence electrons might be in the d orbital is when you're talking about the configuration for transition metals.

Jordan Tatang 3L

For there to be a hydrogen bond does a hydrogen atom have to be covalently attached to N,O, or F in one molecule and then have a hydrogen bond with N,O, or F in the other molecule? Or can it be another atom in the other molecule?

Jordan Tatang 3L

A dipole is a bond or molecule with opposite charges. An example would be H20.
The Hydrogen ends are positive and the oxygen is negative. These charges allow for bonding with other molecules and ions.

Jordan Tatang 3L

A quick way to do it is just valence electrons - lone pair electrons - bonds
or Formal Charge = Valence — # of dots — # of lines

Jordan Tatang 3L

Another way to think of it is that because the half and fully filled d orbitals are more stable, the element really wants to have that configuration and will take 1 electron from the preceding s-orbital in order to do so.

Jordan Tatang 3L

Adding on to that, some other atoms that don't have an octet are hydrogen, helium, lithium, and beryllium.

Jordan Tatang 3L

Since elements in the third period of the periodic table have the d orbital available, does that mean that they can have up to 18 valence electrons?
Like would sulfur be able to have 9 bonds with other elements?

Jordan Tatang 3L

This site has a pretty good acronym https://www.prospectivedoctor.com/mcat- ... ic-trends/

Jordan Tatang 3L

I'm not entirely sure but I believe it has something to do with the d orbital having 10 electrons.

Jordan Tatang 3L

Hi! So you're correct in that you the 5s orbital would get filled prior to the 4d orbitals. However, silver's electron configuration is an exception similar to copper. The 4d orbital is much more stable with 10 electrons instead of 9 so it takes one of the electrons from the 5s orbital. Hopefully th...

Jordan Tatang 3L

Hi! For this question you need to know that the ions of a certain element still have the same nuclear charge but a different number of valence electrons. Rubidium has 1 valence electron in the 5th shell, Rb - has 2 valence electrons but in the 5th shell, and Rb + has 8 valence electrons but in the 4...

Jordan Tatang 3L

hi! I'm pretty sure it's the particle model since energy is proportional to frequency.

Jordan Tatang 3L

Hi! I think in short the answer to your question is that you can't use E=hv for any object with mass. That equation is for a photon which doesn't have any mass while the de broglie equation is for objects with mass and momentum.

Jordan Tatang 3L

I think the main notation for this would just be the up/down arrows in the orbitals.

Jordan Tatang 3L

So I don't think you necessarily will have to determine the fourth quantum number but it just tells you whether the electron is spinning up or spinning down. This also confirms the idea that no two electrons in the same atom have the same four quantum numbers.

Jordan Tatang 3L

Hi! So the question you shared asked for you to find the initial n, energy level. Like you said, you're going to need the final energy level. The question gives you the frequency of the light which you can use in the c = (frequency)(wavelength) equation and rearrange it into c/(frequency) = waveleng...

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