CHEMISTRY COMMUNITY

Marina Georgies 1C

Catalysts are enzymes; they are "recycled." So look for the substance that appears as a reactant in the first step of a reaction, and the reappears later as a product.

Marina Georgies 1C

Q; How does sulfer communicate with other elements?
A: A sulfone.

Marina Georgies 1C

A neutron walks into a shop and says,"I"d like a coke."
The shopkeeper serves up the coke.
"How much will that be?" asks the neutron.
The shopkeeper replies, "For you? No charge."

Marina Georgies 1C

Why does hamburger yield lower energy than steak?
Because it's in the ground state.

Marina Georgies 1C

I asked the guy next to me if he had any sodium hypobromite. He said NaBrO.

Marina Georgies 1C

Why was the mole of oxygen molecules excited when he left the singles bar?
He got Avogadro's number!

Marina Georgies 1C

to add onto the previous reply, that is why unique rates are formatted the way they are. coefficients are incorporated

Marina Georgies 1C

how to tell the difference between a plumber and a chemist: ask them to pronounce the word "unionized"

Marina Georgies 1C

If I had a choice between DNA and RNA, I'd choose RNA because it has U in it.

Marina Georgies 1C

Did you hear about the galvanic cell that went to court?

He got charged with a salt and battery!

Marina Georgies 1C

The book calls it a hidden assumption, but basically know that the cell is operating reversibley, so the potential difference calculated is the maximum source of potential that can be produced. The equation for Ecell only works when the pushing power of the cell is balanced against an external match...

Marina Georgies 1C

to add onto the previous reply, if you don't want to think of it solely in terms of spontaneity, you could also infer that K>1 because Ecell>0, which means products are favored, and this is due to the relationship between E and K, as seen in the equation derived in section 4.8

Marina Georgies 1C

Th toolboxes on 563 and 575 are helpful!

Marina Georgies 1C

cant confirm but I want to say yes. in lecture dr lavelle said its the balancing coefficient of both the reduction and oxidation half reactions, and that they are they same number. makes sense because electrons are conserved in redox rxns

Marina Georgies 1C

I assume you mean oxidation number/state. When it increases, the element is being oxidized, and when it decreases, reduced.

Marina Georgies 1C

you can also use the following equation to help you remeber: E= -w/charge, where work done is in joules, and charge is in coulombs. J/C is V (volts)

Marina Georgies 1C

The reason O2's oxidation number is 0 is that oxidation states of atoms in their elemental states is zero. Oxygen gas is diatomic, often found in nature as O2, so that is why its oxidation number is zero. The same cannot be said for O3 however, and its oxidation number is -6 (3 x 2 O's)

Marina Georgies 1C

It would make sense seeing as they as both state functions so you're probably right!

Marina Georgies 1C

number the many possible positions molecules can be arranged in in a system. #possible states^#particles=degeneracy (W)

Marina Georgies 1C

Enthalpy can be measured quantitatively because of processes like calorimetry. It is essentially heat, and we use temperature to measure it directly. Entropy is the measure of how disordered a system is, so it is harder to give it a number value, however; the equation S=kblnW allows you to calculate...

Marina Georgies 1C

Another way to think about it is how gases behave logically. They're not going to ever want to revert to a state where they have less space/freedom to move around. And a generally good rule of thumb is that gases are always going to want to go to a state of increased entropy, as explained in the pre...

Marina Georgies 1C

You can think of a spontaneous reaction as something that occurs on its own, without an external nudge, i.e. an input of energy. A reaction that requires an input of energy does not occur on its own, and is therefore not "spontaneous."

Marina Georgies 1C

The equation is similar when dealing with pressure right? Except it's Pinital/Pfinal because of the inversely proportional relationship between P and V?

Marina Georgies 1C

From the textbook: "The fundamental molecular difference between work and heat is related to the orderliness with which atoms in the surroundings move. When energy is transferred as work, the system moves molecules in the surroundings in a definite direction... During the transfer of energy as ...

Marina Georgies 1C

Those are right! Also in the last step, AD turns into deltV (change in volume) because it is referring to area x distance (height). Page 263 of the textbook has diagrams that demonstrate this series of equations.

Marina Georgies 1C

Chris Lamb 1G wrote:[quote="Marina Georgies 1C" Sidenote- where is Dr. Lavelle's list of errors posted? I can't seem to remember.

It is a PDF on the 14B page titled "Solution Manual Errors"
Here it is:https://lavelle.chem.ucla.edu/wp-content/supporting-files/Chem14B/Solution_Manual_Errors_6Ed.pdf[/quote]
Thankyou!!!!

Marina Georgies 1C

I may be wrong but I believe you are referring to irreversible vs reversible processes. A reversible process can be reversed by infinitely small changes in a variable (such as volume), and these infinitesimal changes are so tiny that they result in the maximum amount of work done. In the end, though...

Marina Georgies 1C

Although most math classes teach the rule that .5 or 5 rounds up, another commonly accepted method is to round to the nearest even number. I think the method of rounding commonly used in chemistry is the second one, as mentioned in the previous replies. So they are correct about rounding a 5 or .5 t...

Marina Georgies 1C

I keep running into the same problem with this question, and I also believe it could be an error. Sidenote- where is Dr. Lavelle's list of errors posted? I can't seem to remember.

Marina Georgies 1C

It's really easy to confuse isolated and closed systems but the key in this example is to recognize that the mercury is affected by the temperature outside, so there there is an exchange of energy in the form of heat between the contents of the system (mercury) and the surroundings.

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