CHEMISTRY COMMUNITY

Kathy Vu 3L

Instead of having (tert-butyl), can you use isopropyl?

Kathy Vu 3L

Tert- just implies that there is a carbon attached to 3 other carbons, it does not necessarily have to be (CH3)3C-.

Kathy Vu 3L

Can 2-pentene and pent-2-ene be used interchangeably?

Kathy Vu 3L

The more polar a molecule, the more regions of electron density. Therefore, these regions of molecules act as a nucleophile.

Kathy Vu 3L

H20 also has lone pairs, which could be attracted to the positive electrophiles.

Kathy Vu 3L

When you derive the equation for a zero and first order reactions by integrating, it comes out to be -kt, as opposed to integrating the second order reaction and having it come out to be kt. Therefore the slope is negative for zero and first order.

Kathy Vu 3L

On the quiz it helps that he put the table of bond enthalpies on the side, so you know which ones are going to be used. For me, I draw the lewis structure out and I see which one changes between both of them.

Kathy Vu 3L

Using the equation ∆G° = – RT ln K, it assumes that the system is already in equilibrium since K is the equilibrium constant. Furthermore, ∆G° is only 0 when at equilibrium, K equals 1, which means the reactants and products are equally favored.

Kathy Vu 3L

Irreversible processes cause a change in entropy, whereas reversible processes have an entropy change of 0.

Kathy Vu 3L

You cannot change the energy of an isolated system, as stated in the first law of thermodynamics. This law states that the internal energy of an isolated system is constant. For example, the universe is an isolated system, therefore its energy is constant.

Kathy Vu 3L

When I bought my course reader, it did not come with a workbook like last quarter. Is this a new change or have others received a workbook?

Kathy Vu 3L

Resonant structures are used to show delocalized electrons, therefore you would have to draw all the possible bondings, even if they are not stable. As for finding out how many structures to draw, I just look at all the possible places that the double/triple bond can go.

Kathy Vu 3L

Strong acids do have a Ka value, they are just very large since strong acids dissociate almost completely, therefore the products/reactants ratio would be very high, making the Ka value high.

Kathy Vu 3L

You're right the answer is C. A TRUE, definition of a chemical equilibrium B TRUE I think refers to Le Chatelier's Principle, so even if you add different combos of reactants and products, the reaction will still end up at equilibrium by shifting to one side of the reaction C FALSE there is a reacti...

Kathy Vu 3L

You don't need the starting concentration because the equation for calculating K is [NH3][H2S], since NH3 and H2S have the same stoichiometric coefficients of 1, you can replace what's in the bracket as X. So 0.11=X^2, and X=0.11^(0.5), which is 0.33atm

Kathy Vu 3L

It has to deal with electron repulsion. For z<8, π2p MO’s are filled before the σ2p MO because there is less electron-electron repulsion between the π2p and the σ2s and the σ2s*. For z>8, σ2s and σ2s* MO’s are closer because greater nuclear charge, therefore the σ2p MO's will react less strongly wit...

Kathy Vu 3L

Atoms with access to the d-block can also have an expanded octet. For example, sulfur has access to the 3d-block which is why it can take electrons from there to have an expanded octet.

Kathy Vu 3L

The formal charge isn't 0 and 0, however if there were to be a double bond between the two, then carbon wouldn't have an octet.

Kathy Vu 3L

Two chemists walk in a bar. One asks for H20, and the other says "I'll have H2O too." The second chemist dies.

Kathy Vu 3L

I think that value is applicable to all object's wavelength. I would not say values less than 10^-15 don't have properties, because all objects have wave-like properties, but only those with small mass and high velocity can be measured.

Kathy Vu 3L

Can I ask what questions you're referring to, because most questions I've seen, ask about the speed of the ejected electron (in which you use the photoelectric effect equation) or what wavelength you need to eject an electron.

Kathy Vu 3L

The limiting reactant limits the amount of product that can be formed and is completely consumed, therefore the other reactant (excess reactant) will remain when the reaction stops.

Kathy Vu 3L

Is there usually a range of answers we can put on quizzes and exams, or is there only 1 answer that is allowed?

For example what if my answer is 2.5, but others got 2.6 due to a different amount of decimals used during calculations

Kathy Vu 3L

Rob_Carter_1L wrote:Just confirming, I know that 0.0100 would have 3 sigfigs due to trailing zeros, but would 1.00 have 3 as well? Is it the same after decimal points?

Yes, 1.00 would have 3 significant figures as well since the 2 zeros are trailing zeros behind a decimal point

CHEMISTRY COMMUNITY

Search found 24 matches

2012 Final Q6D: Naming Cycloalkane

Re: Neo- vs. Tert-

Numbering in Naming Alkenes

Re: Polarization and nucleophile strength

Re: Nucleophiles that are Neutral?

Re: Slope of k

Re: Bond enthalpy question on quiz 1

Re: Free energy at equilibrium

Re: Entropy

Re: Isolated Systems [ENDORSED]

Workbook?

Re: Do all resonance structures need to be FC=0?

Re: Indicators of strong or weak acid/base

Re: Reaction at equilibrium

Re: Fall 2014 Quiz #8 [ENDORSED]

Re: MO Diagram difference

Re: Lewis Structure Octet Rule Exceptions

Re: Lewis Structure for CO

Re: Post All Chemistry Jokes Here

Re: Worked Example on page 52 in the Course Reader

Re: Wavelength of Ejected Electron [ENDORSED]

Re: Mass Always Equal?

Re: Significant figures [ENDORSED]

Re: Trailing zeroes [ENDORSED]