CHEMISTRY COMMUNITY

JakeSaum_1A

What is the chemical formula for ice?

H2O cubed

JakeSaum_1A

Why did Mr. Watt work in the jewelry store?

He could sort through 1 Joule per second

JakeSaum_1A

Anyone know any sodium jokes?

Na

JakeSaum_1A

This is how I understand it: Catalysts are needed to drive a reaction. You'll typically see them in the reactants of the first step. Intermediates are produced over the course of the reaction. If you are given two steps, they will typically be in the products of the first step and the reactants of t...

JakeSaum_1A

What is the difference between Ea and the E we learned about previously?

JakeSaum_1A

Why are atoms untrustworthy?

They make up everything

JakeSaum_1A

What's the sign of a bad chem joke?

No reaction

JakeSaum_1A

What did the scientist say when he found two Helium isotopes

HeHe

JakeSaum_1A

What is the highest order a reaction has ever been recorded?

JakeSaum_1A

How do we determine which elementary step is the slowest in a reaction? Or will that always be given to us by experimental results?

JakeSaum_1A

Silver walks up to gold in a bar and says

"Au! Get out of here!"

JakeSaum_1A

What is Cesium and Iodine's favorite show?
CsI

JakeSaum_1A

What did one charged atom say to the other?

I've got my ion you

JakeSaum_1A

Do concentration cells work similarly to a concentration gradient in the membrane of a biological cell?

JakeSaum_1A

If E under standard conditions always = 0V, does that mean concentration cells only produce electrical energy under non standard conditions? Or is E(not) accounting for after the solutions reach equal concentration?

JakeSaum_1A

Did you hear about oxygen's date with potassium?

It went OK

JakeSaum_1A

Did you hear the one about cobalt, radon, and yttrium?

It was CoRnY

JakeSaum_1A

I tried writing a chemistry joke but it was out of my element

JakeSaum_1A

I don't think it matters which side they are on, but it's just important to know that electrons always flow from anode to cathode. Because if you were looking at a 3D version of Lavelle's example straight on, the anode would be on the left and cathode on the right, but if you walked around to the ot...

JakeSaum_1A

When a battery "runs out of juice" does that mean that either the cathode or anode has dissolved so much that it will not carry out the reaction anymore?

JakeSaum_1A

What kind of fish is made out of two sodium atoms?
2Na

JakeSaum_1A

What kind of dogs do chemists have?

Laboratory retrievers

JakeSaum_1A

Why did Mr. Watt work in the jewelry store?

He could sort through one Jewel per second!

JakeSaum_1A

I was just wondering if there could be a case where DeltaH is positive and DeltaS is negative and it would still be spontaneous because you have a very low temperature?

JakeSaum_1A

If Delta S of the system and Delta S of surroundings are equal and opposite, Would that mean delta S universe always equals 0?

JakeSaum_1A

What is the name of 007's eskimo cousin?
Polar Bond

JakeSaum_1A

Why does a hamburger yield lower energy than a steak
Because it's in its ground state

JakeSaum_1A

Why do chemists enjoy working with ammonia?
It's pretty basic stuff

JakeSaum_1A

What are the characteristics of a system in which entropy increases and what are the characteristics of a system in which entropy decreases?

JakeSaum_1A

What exactly constitutes external pressure? Is it the pressure pushing down on the piston, the pressure inside the beaker, or the difference between the two, or something else?

JakeSaum_1A

Why did the white bear dissolve in water?
Because it was polar

JakeSaum_1A

What's the dullest element?
Bohrium

JakeSaum_1A

I'm confused too, but my understanding was that since P (internal) is approximately equal to P(external), there is very little fluctuation between the two

JakeSaum_1A

I'm kinda confused about most of these things too. But I believe that a system at equilibrium is reversible because the external and internal forces on opposing sides would be equal to each other whereas a system not at equilibrium would be irreversible because one force is greater than another. For...

JakeSaum_1A

Hi so I understand that an exothermic reaction releases heat and an endothermic reaction absorbs heat, but for cases like "ice melting is an endothermic reaction" I get a little confused. In order for a reaction to be exothermic, does the whole system have to increase in heat? Because I wo...

JakeSaum_1A

What did the chemist say after the explosion in the lab?

Oxidants happen

JakeSaum_1A

Why was Avogadro a mini golf champ?

He always got a mole in one

JakeSaum_1A

Why do chemists enjoy working with ammonia?

It's pretty basic

JakeSaum_1A

If a molecule has three atoms (let's say carbon is the central atom) and it is bonded to a very electronegative atom and a relatively non electronegative atom. Would the pull of the electronegative atom affect the bond enthalpy between the carbon and the non electronegative atom?

JakeSaum_1A

In table 5G.2 in the textbook, it gives the K and Kc of certain reactions at different temperatures. I am confused about why the K values and Kc values differ. What is the difference between the two?

JakeSaum_1A

What do you call a clown in jail?

A silicon

JakeSaum_1A

What do chemists call a benzene ring with iron atoms instead of carbon atoms?

A ferrous wheel

JakeSaum_1A

If Iron man and the Silver Surfer teamed up, they'd be alloys

JakeSaum_1A

How are pH and pOH and pKa and pKb related? Does pH = pKa and pOH = pkB?

JakeSaum_1A

Is it possible to have a large Kc in chemical formula that results in cubic equations? Or are we just staying away from that in an effort to keep complexity out of it?

JakeSaum_1A

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

JakeSaum_1A

I was going to tell a chemistry joke but I was afraid I would get no reaction

JakeSaum_1A

Why is it that when you add an inert gas to a reaction, the volume does not decrease?

JakeSaum_1A

In lecture, Le Chatelier's principle was applied to N2 + 3H2 <--> 2NH3. Dr. Lavelle said if we increase N2, H2 decreases and 2NH3 increases. My question is, would it ever get to the point where the amount of NH3 would no longer increase because H2 would end up being a limiting reactant because you a...

JakeSaum_1A

In lecture, Dr. Lavelle says that if K is greater, concentration of product is greater at equilibrium. I would think that the concentrations of reactants and products would be close to equal if they were in equilibrium. I know now I am wrong to assume this, but does someone have an example of a chem...

JakeSaum_1A

If H2O is the formula for water, what is the formula for ice?

H2O cubed

JakeSaum_1A

On question 7 (Redrawing Methyl-2-Cyanocrylate) Dr. Lavelle adds 3 Hydrogen atoms to the Carbon atom on the far right of the molecule. How did he know to do that? Or is that the common procedure in making sure Carbon has four bonds?

JakeSaum_1A

Why did the man get lead poisoning after eating lunch?

He had a Pb&J

JakeSaum_1A

What do the points labeled A,B,C,D,E in the titration diagram from lecture stand for? Are they as important as the stoichiometric point?

JakeSaum_1A

In the Titration diagram, what do the points labeled A,B,C,D, and E stand for? Are they as important as the stoichiometric point?

JakeSaum_1A

I tried to come up with a joke about the periodic table but I was way out of my element

JakeSaum_1A

Using the picture the last person included, it basically means whatever is left over from the acid losing an H+ will be a conjugate base and vice versa for Conjugate acids

JakeSaum_1A

What does the word "conjugate" mean when regarding acids and bases and what causes an acid and base to be conjugate?

JakeSaum_1A

Will there ever be a time where there are absolutely zero Hydronium ions or absolutely zero Hydroxide ions in a solution or will there always be at least a little of each in a solution?

JakeSaum_1A

I missed why the H atom from the HCl moves over to the H2O atom to form H3O. Did that happen because of the strength of the lone pairs on O? If not, can someone please explain why this happens?
Thanks

JakeSaum_1A

Why are chemists good at solving problems? They have all the solutions

JakeSaum_1A

Did you hear about the guy who was cooled to absolute zero? He's 0K now.

JakeSaum_1A

A photon walks into a hotel and is asked if he needs help with his luggage. He says "no thanks. I'm traveling light."

JakeSaum_1A

The example from the lecture was something like CoCl2(NH2)4. Prof. Lavelle described a chelate as a complex containing a ligand that forms a ring of atoms that include the central metal atom. He then drew a ring connecting the NH2s and the Co but the Cl atoms didn't seem to be a part of the ring. Is...

JakeSaum_1A

Why is it that sp3 hybridization has 4 hybrid orbitals while sp2 hybridization uses 3 hybrid orbitals and 1 p orbital? I'm having a hard time understanding why those two work differently. Like why wouldn't sp2 have 4 hybrid orbitals as well?

JakeSaum_1A

Anyone know any jokes about Sodium?

Na

JakeSaum_1A

For example, do there tend to be more sigma bonds in a polar molecule? Or are there more pi bonds in a non polar molecule? Or is there even a pattern to it at all?

JakeSaum_1A

When given a molecule with a double bond, how do we determine which of the bonds (in the double bond) is sigma and which is pi?

JakeSaum_1A

In the last example of the lecture with Cis and Trans Dichloroethene, it had two carbons in the middle that were double bonded to each other and each single bonded to a Hydrogen and a Chlorine. The reason I ask is that when determining the shape, would I begin with A2? All of the other examples in t...

JakeSaum_1A

With water, we see that the lone pairs have to be close to each other so that it decreases the bond angle below 180 degrees. But what would be an instance where the lone pairs are as far as possible from each other? Thanks

JakeSaum_1A

It's just everything up to Wednesday and the last few sections of outline 2

JakeSaum_1A

Can you only assign shape to a molecule if all of the bond angles are the same? For example, CH4 was tetrahedral because all angles were 109.5 degrees. But We didn't assign a shape to NH3 in the lecture because the lone pair had more repelling power. Why is this the case?

JakeSaum_1A

In one of the homework problems, it asks which can form a hydrogen bond out of H-Cl, H-I, H-Br, and H-F. The answer was H-F because it was the only one of the four where the H was bonded to either N, O, or F, but I also noticed that the difference between the electronegativities of H and F was great...

JakeSaum_1A

I don't think it's that the bonds are both ionic and covalent at the same time. I think it's that bonds often have properties of both. For example, and ionic bond occurs between two oppositely charged atoms. This is similar to how a polar covalent bond acts. Like how water has a more negative Oxygen...

JakeSaum_1A

In lecture, Dr. Lavelle talks about Ion-Ion and Ion-Dipole interactions for example. In the ion-ion interaction a -250kJ/mol number is attached to it. I'm a little confused about where this number comes from and why it is negative. Any help would be appreciated. Thanks!

JakeSaum_1A

If the molecule has an overall positive charge then you add a + to the outside and if it has an overall negative charge, you add a - to the outside

JakeSaum_1A

When I am drawing Lewis structures of atoms, I am confused about when to add an extra pair of electrons to atoms. For example, in the homework, I had to draw the phosphate ion (PO4 3-) and the correct answer had me add 3 single bonds and a double bond from the P atom to the O atoms. Why wouldn't it ...

JakeSaum_1A

In lecture, prof. Lavelle says that most bonds have both ionic and covalent character. He then describes how a molecule that has two atoms with unequal pull on electrons has ionic characteristics. Does this mean that a polar covalent bond has ionic characteristics?

JakeSaum_1A

Hi, I'm running into homework problems that say my answer is wrong if I don't simplify the formal charge. How would one decide whether they have to simplify it or not, and what does it mean to do so? Thanks

JakeSaum_1A

I'm a little unclear as to what accounts for differences in bond length. Why were double bonds about 120 Angstroms and Single bonds 140 Angstroms?

JakeSaum_1A

Why do chemists like nitrates so much?
They're cheaper than day rates.

JakeSaum_1A

There was a homework problem that asked for the electron configuration of Si and the answer started off with [Ne]. Just curious, why not start off with [Al] (the element immediately preceding Si) so you only have to write [Al]3p2? Is there a rule against doing that?

JakeSaum_1A

Threshold energy is the amount of energy it took to remove an electron from a metal surface in the photoelectric effect experiment. Is ionization energy the same principle as threshold energy since it's the amount of energy needed to remove an electron from an atom? Or are they two different concept...

JakeSaum_1A

In the lecture, when prof. Lavelle was finished writing down the shell letters and numbers, he started drawing arrows. I noticed how he drew 3 up arrows before complementing them with down arrows. Why did he do this and how did he know how many arrows to put? Thanks.

JakeSaum_1A

What's the difference between an orbital and a sub shell?

JakeSaum_1A

Would someone be able to explain how Prof. Lavelle determined the 4 quantum numbers from the 5s orbital? Thanks

JakeSaum_1A

Does the fact that having a diameter that is 10^-15 is too small to be possible have anything to do with the fact that the smallest detectable wavelength is 10^-15 also?

JakeSaum_1A

Will the mass in the denominator of the De Broglie equation always be in kilograms?

JakeSaum_1A

What is the smallest exponent that would be a detectable wavelength? Thanks!

JakeSaum_1A

The experiment that shows constructive interference causes light to be indirectly shown behind a part of the screen where there is no opening, but what would destructive interference look like in an example like this?

JakeSaum_1A

I see that the transitions are longer between energy levels in the Lyman series, but what are the main differences between the two?

JakeSaum_1A

When moving an electron from n=1 to n=2, would it be good to think to the E=hv as a bridge to get from one energy level to another?

JakeSaum_1A

As I'm understand it from the lecture, I believe that being ejected means electrons leaving the atom altogether due to increased wave frequency, and being excited means moving from one energy level to another while still remaining within the atom.

JakeSaum_1A

Just to clarify, when one changes INTENSITY of the light, it means making the light brighter or dimmer vs. when one changes the WAVELENGTH of light, it means changing, for example, from visible light rays to UV rays?

JakeSaum_1A

In the lecture, Dr. Lavelle talks about turning the nozzle of a watering can so that the opening is so small that only individual units of water molecules are coming out at a time. At what point/unit size should we stop considering going the classical mechanics route and focus on quantum mechanics?

JakeSaum_1A

I'd tell another chemistry joke but it looks like all the good ones ARGON

JakeSaum_1A

Why did the attacking army use ACID weapons?
To neutralize the enemy BASE

JakeSaum_1A

In order to avoid fractions, multiply both sides by 2 just as you would in a math problem

JakeSaum_1A

I write down how many of each element are on each side of the equation. For example in NH3 + O2 --> N2 + H2O 1N 2N 3H 2H 2O. 1O From here, I add numbers to the equation and change them in my list underneath until all numbers match on both sides.

JakeSaum_1A

I had to determine what composes 2-butanone to find the g/mole.

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