CHEMISTRY COMMUNITY

Jeannie_Kim_1I

The voltage values would probably be given either on that page of the exam or on a separate sheet of reduction reactions and their respective voltage values.

Jeannie_Kim_1I

We should know that alkynes indicate a carbon triple bond, but (like you said) we should probably focus more on alkanes and alkenes.

Jeannie_Kim_1I

When alphabetizing, we would take iso- and neo- into account, but not sec- or tert-.

Jeannie_Kim_1I

The activation energy of an endothermic reaction is greater than that of an exothermic reaction, but you can't determine if a reaction is endothermic or exothermic by looking at the activation energy.

Jeannie_Kim_1I

You can look on page 70 in the course reader for that.

Jeannie_Kim_1I

You should leave it and round off your final answer.

Jeannie_Kim_1I

The final volume is V2. I think you got it confused with pressure. For pressure, deltaS=nRln(P1/P2).

Jeannie_Kim_1I

First you solve for work (w=-P_extdelta V) to get -1.48 L atm, which you convert to -0.150 kJ. Then you use delta U=q+w. In this case, it would be 5.50 kJ (which is given to us in this problem) + (-0.150 kJ) = 5.35 kJ. Hope this helps!

Jeannie_Kim_1I

Delta H is considered a specific type of q. Delta H=q_p.

Jeannie_Kim_1I

Dr. Lavelle said in an earlier post that the reason why we're not turning in workbook quizzes to replace a quiz grade is that there are ~1200 students taking Chem 14B this quarter, so that would be way too many quizzes for his TAs to grade.

Jeannie_Kim_1I

Would we need to know how to draw MO diagrams for heteronuclear diatomic molecules that are not in the same period (i.e. NaF)?

Jeannie_Kim_1I

If the k value is equal to 10^-5, would we keep the x in the denominator and use the quadratic equation?

Jeannie_Kim_1I

Boron can break the octet rule. So you could add a lone pair to BF3 (which, by the way, doesn't even follow the octet rule anyway), which is why BF3 is a Lewis acid.

Jeannie_Kim_1I

You would disregard the C(s) because it's a solid. So there's 1 mole on the reactant side and 2 moles on the product side, which is why the reactant side is favored.

Jeannie_Kim_1I

I'm pretty sure we will need to know all of the ligands on that one page in the course reader.

Jeannie_Kim_1I

You look at the formal charges. For example, in [Cr(edta)]-1 the oxidation number for chromium is +3 because the formal charge of edta is -4 and the overall charge is -1, so +3-4=-1.

Jeannie_Kim_1I

When determining hybridization, we look at the Lewis structure and count lone pairs (and bonding pairs) as regions of electron density. And we do, whenever necessary, include lone pairs when we draw Lewis structures, meaning it is not considered atypical for a Lewis structure to have lone pairs.

Jeannie_Kim_1I

If there's an extra electron, it's a -1 charge. For example, if there are 6 electrons around N, there would be a -1 because N only has 5 valence electrons. If an electron is missing, it's a +1 charge. Going back to the N example, if N is surrounded by 4 electrons, it would have a +1 charge because a...

Jeannie_Kim_1I

Normally you wouldn't place an element on top of the central element unless there's already elements on the left and right sides. So for example, for CO the O would be on the right side of C, and for CO2 the oxygens would be on the left and right sides, and for CO3 the oxygens would be on the left a...

Jeannie_Kim_1I

4s orbitals are lower in energy when there are no electrons in 3d orbitals, which is why 4s gets filled in first (according to the Aufbau principle). When 3d orbitals start filling up with electrons, they become lower in energy, and 4s orbitals become higher in energy. This is why 3d comes before 4s...

Jeannie_Kim_1I

The energy required to release an electron is the threshold energy. When the energy of a photon is equal to the threshold energy, an electron will initially be released and will drift towards the electron detector due to the electrostatic attraction between the slightly positively charged detector a...

Jeannie_Kim_1I

If you look in the course reader, pages 35-36 tell us everything we need to know about sig figs. Also, I've noticed that sometimes our solution manual doesn't give us consistent sig fig values, but those are errors.

Jeannie_Kim_1I

Dr. Lavelle mentioned that light is made of photon energy, meaning photons consist of energy. The amount of energy a photon has is determined by frequency. The higher the frequency, the higher the energy. Each photon need to have enough energy to interact with one metal atom to eject one electron. H...

CHEMISTRY COMMUNITY

Search found 23 matches

Re: Winter 2014 Q3

Re: Alkyne Naming

Re: Prefixes in Alphabetization

Re: Activation Energy

Re: Homework 15.85

Re: Sig Figs: Rounding Off

Re: Equation

Re: Question 8.9

Re: relationship between delta H and q [ENDORSED]

Re: Workbook quizzes

Re: Heteronuclear Diatomic Molecules

Re: ICE

Re: Embarrassing question about BF3

Re: 11.73 b

Re: Polydentates

Re: Quick way to determine oxidation number?

Re: Regions of Electron Density & Naming Hybrid Orbitals

Re: Formal Charge for Indivual Elements in Compound

Re: Placing elements in Lewis diagram

Re: 3d and 4s orbitals

Re: Module Questions

Re: Sig Figs

Re: About photons.... [ENDORSED]