CHEMISTRY COMMUNITY

davidbakalov_lec2_2L

I am having trouble on this problem, how do you do it?

davidbakalov_lec2_2L

What does it mean for a reaction to be exergonic?

davidbakalov_lec2_2L

Can someone explain 13c from Lyndon's review sheet?

davidbakalov_lec2_2L

Can someone explain #16 from Lyndon's worksheet? How did he get that graph?

davidbakalov_lec2_2L

I'm having trouble balancing the redox reaction.

davidbakalov_lec2_2L

Not necessarily, it can be negative depending on what half reactions are used.

davidbakalov_lec2_2L

How do you do number 17? I can't seem to figure it out

davidbakalov_lec2_2L

Since everyone has taken the test it is fine if you discuss it

davidbakalov_lec2_2L

The N refers to the order of the reaction. So a first order reaction, where the N is 1, means that the rate of reaction is directly proportional to the concentration of reactants. r = k[A]^1

davidbakalov_lec2_2L

Thank you so much Joyce!

davidbakalov_lec2_2L

Q: What kind of fish has two sodium atoms?
A: 2Na.

davidbakalov_lec2_2L

The oxidating agent is the reactant that is reduced in a chemical reaction, and the reducing agent is the reactant that is oxidized in a reaction.

davidbakalov_lec2_2L

They are the same thing, the name is interchangeable.

davidbakalov_lec2_2L

You can tell by looking at which half reaction is reduced and which is oxidized. The anode is the one in which oxidation occurs and the cathode is the one in which reduction occurs.

davidbakalov_lec2_2L

I wrote the Qp with two significant figures as well but didn't get any points off. I don't see why points would be taken off considering that the question does not explicitly ask you to find the Qp. However, it makes sense that if two of the known conditions are only known to one sig fig, then that ...

davidbakalov_lec2_2L

I would be prepared to work through and understand chemical processes under those conditions just in case. Thermodynamics usually involves at least one of those 3 conditions being held constant.

davidbakalov_lec2_2L

davidbakalov_lec2_2L

davidbakalov_lec2_2L

The boiling point is the minimum temperature at which this reaction could be spontaneous. Any temperature higher than the boiling point, the reaction would automatically favor the gas state and be spontaneous.

davidbakalov_lec2_2L

Q: What do you call a clown in prison?
A: Silicon

davidbakalov_lec2_2L

These assumptions are usually made to simplify the concepts, and you should be told usually if you aren't working with a gas in ideal conditions. As for constant pressure, that sometimes is required (like in measuring enthalpy).

davidbakalov_lec2_2L

Spontaneous processes are those which tend to occur without needing external influence, and the tendency of nature is to proceed towards greater disorder and more randomness. This is why entropy, the measure of this disorder, increases for spontaneous processes.

davidbakalov_lec2_2L

Q: If H2O is the formula for water, what is the formula for ice?
A: (H2O)^3.

davidbakalov_lec2_2L

I’d tell more chemistry jokes, but the best ones argon.

davidbakalov_lec2_2L

I personally don't think we would get many or any problems with isolated systems because as you said nothing would change, so there would be no calculations to do.

davidbakalov_lec2_2L

Heisenberg is out for a drive when he’s stopped by a traffic cop. The cop says: ” Do you know how fast you were going? Heisenberg replies: “No, but I know where I am”.

davidbakalov_lec2_2L

Q: Why does hamburger have lower energy than steak?
A: Because it’s in the ground state.

davidbakalov_lec2_2L

Q: What do you call a tooth in a glass of water?
A: A one molar solution.

davidbakalov_lec2_2L

Solids and liquids are present in such large quantities in comparison to the rest of the molecules that including them in the equilibrium constant equation is unnecessary because it wouldn't make a significant difference.

davidbakalov_lec2_2L

The main way to compare is to look at their corresponding Ka values. Higher values mean that the forward reaction is more favored, which thereby means that the acid dissociates to a greater extent and is therefore stronger.

davidbakalov_lec2_2L

Q: What did one charged atom say to the other?
A: I’ve got my ion you.

davidbakalov_lec2_2L

Old chemists don’t die, they just stop reacting.

davidbakalov_lec2_2L

Looking at the difference in moles only works for reactions in which the products and reactants are gaseous. Such reactions typically prefer the direction in which the pressure is lowest, which in this case is when as few moles as possible are present.

davidbakalov_lec2_2L

The direction the reaction goes if it is endothermic or exothermic is mainly affected by the change in temperature of the reaction vessel. Since a change in temperature causes a change in K, I am not sure if Q can be used to determine the direction the reaction would go.

davidbakalov_lec2_2L

Organic chemistry is difficult. Those who study it have alkynes of trouble.

davidbakalov_lec2_2L

Bronsted acids and bases focus on the proton, so an Bronsted acid is a proton donor and a base is a proton acceptor. Lewis acids and bases focus on the electron, so an acid in this case is an electron acceptor and a base is an electron donor. I am not quite sure, however, whether we work with one mo...

davidbakalov_lec2_2L

I think you are right. The only mention of 'cyano' in 17.5 is naming it isocyano if the N atom is linked to the metal atom, but I don't think we can be expected to know this. Also, the complex in 17.29 is already named in the book : "hexacyanidoferrate(II) ion" on pg 741. I think it is lik...

davidbakalov_lec2_2L

Silver walks up to gold in a bar and says, "Au, get outta here!"

davidbakalov_lec2_2L

What did one charged atom say to the other? I've got my ion you.

davidbakalov_lec2_2L

Q: What do you do with a dead chemist?
A: Barium

davidbakalov_lec2_2L

You can't really just know the amount of sigma and pi bonds by eyeballing the molecular formula, so in most cases you will need to draw out the lewis structure and look at the bonds there to determine it.

davidbakalov_lec2_2L

The hybridization is based solely on the amount of "things" around the central atom, whether it's a lone pair or another atom, it will always be the same for a certain amount. So if there are 4 "things" around the central atom like in the tetrahedral or trigonal pyramidal case, t...

davidbakalov_lec2_2L

The specific decreases in angles caused by the presence of lone pairs can only be determined through experimentation, so you won't be expected to know the exact angle values.

davidbakalov_lec2_2L

A quick rule of thumb to determine the polarity of a molecule is to look at how symmetrical it is. If the arrangement of the atoms is symmetrical, it will most likely be non polar.

davidbakalov_lec2_2L

Florence Flask was getting ready for the opera. All of a sudden, she screamed: "Erlenmeyer, my joules! Somebody has stolen my joules!" The husband replied, "Calm down, honey. We'll find a solution."

davidbakalov_lec2_2L

The shortcut to find the formal charge is to take valence electrons - (# of lines + # of dots)

davidbakalov_lec2_2L

When you divided all values by 3.15, you should have gotten about 1.14 for C. This is not close enough to 1 to round, so you should've multiplied all numbers by 7.

davidbakalov_lec2_2L

Did he say that polarizability will be covered on the midterm?

davidbakalov_lec2_2L

The electronegativity of an element is determined by the element's electron affinity and its ionization energy. The difference in the electronegativity between the two elements is quite small, but the main reason for it is because chlorine is one period below oxygen. Chlorine's valence electrons are...

davidbakalov_lec2_2L

So is the format going to be similar to the discussion tests we've been taking?

davidbakalov_lec2_2L

I am planning on going back through all the homework problems as well as going through the questions that the UA posted on chemistry community for us.

davidbakalov_lec2_2L

The degeneracy of a 3p orbital, for example, would be 3 because that is the amount of orbitals inhabiting it.

davidbakalov_lec2_2L

Do you have mole problems? If so, call Avogadro at 602-1023.

davidbakalov_lec2_2L

ml is the magnetic quantum number. It serves to distinguish the individual orbitals in a sub shell (l). ml can take the values from -l to l. So if l = 1, ml = -1, 0, or 1. l = 1 signifies the p-orbital, so these 3 numbers can also be written as px, py, and pz. This means that there are three orbital...

davidbakalov_lec2_2L

The reason p- and d- orbitals have non-symmetric density in comparison to the s- orbital has to do with the angular momentum of the electrons. Electrons in the s-orbital have no angular momentum (l = 0), so they are simply distributed around the nucleus instead of circulating it. Electrons in greate...

davidbakalov_lec2_2L

What should you do if no one laughs at your chemistry jokes?

Keep telling them until you get a reaction.

davidbakalov_lec2_2L

I found some erasable pens on amazon so I'm just going to try using them on tests.

davidbakalov_lec2_2L

All electromagnetic waves travel at the speed of light 'c', hence the equation c = wavelength * frequency. Because frequency and wavelength are inversely proportional to each other, a decrease in frequency will affect the wavelength but not the speed - which is a constant.

davidbakalov_lec2_2L

Q: What kind of fish is made out of 2 sodium atoms?
A: 2 Na

davidbakalov_lec2_2L

So is it generally safe to not worry about sig figs in your calculations until you reach your final answer? When showing our work on tests do you think it'll be ok to use exact numbers until the end of the problem?

davidbakalov_lec2_2L

I believe the unit you are thinking of is the Ãngström, 1Ã = 10^(-10).

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