CHEMISTRY COMMUNITY

Jacqueline Lee

That's because n is equal to the number of electrons transferred which when we look at the balanced half reactions, was 6.

Jacqueline Lee

I think it's because we're looking for pH and the concentrations of Ce3+, Ce4+,MnO4-, and Mn2+ would not contribute to pH because pH is the measure in concentration of H+ so that is what we could focus on instead. So by taking the E (which would be .157) you can divide that by (.05916/5) and then di...

Jacqueline Lee

Is there any other reason besides collision that would explain why the molecules would not just stay in the staggered conformation?

Jacqueline Lee

For the first quiz 3 prep, the answer for question 2 listed the name for CH3CH(CH3)CH(CH2CH3)C(CH3)3 as 2,2,4-trimethyl-3-ethylpentane. Why isn't it 3-ethyl-2,2,4-trimethyl-pentane, having ethyl come before methyl? Also if there are multiple substituents, would the numbers change so the first substi...

Jacqueline Lee

The question goes "The rate constant for reaction A \rightarrow B is 25min -1 at 298K and 35min -1 at 350K. Calculate the Value of the rate constant at 770K. Give your anser in min -1 ." How would one approach the question? I tried treating the given numbers as one finds slope, but the ans...

Jacqueline Lee

Oh, ok. That makes much more sense now. Thank you!

Jacqueline Lee

So from the course reader, $E=E^\circ -\frac{RT}{nF}ln\frac{[P]}{[R]}$ and at 25 degrees Celsius, $E_{cell}=E^\circ -\frac{0.0592}{n}LOG_{10}Q$

but in the practice midterms, they use this formula $E=E^\circ -\frac{0.0257}{n}ln\frac{[P]}{[R]}$ . can someone explain where 0.0257 comes from?

Jacqueline Lee

Why must we balance the half reactions if it doesn't affect the standard reduction potential?

Jacqueline Lee

I'm assuming you're adding the two substances together that then reaches a final temperature. Because the two substances will then share a final temperature, I use the equation q 1 =q 2 therefore mCpT=mCpT Our unknown would then be x, which is the final temperature, not the change in temperature. So...

Jacqueline Lee

Can someone explain the difference between a reversible and irreversible process?

If a system at equilibrium is a reversible process, does that mean a system not in equilibrium is irreversible process? But wouldn't systems eventually return to equilibrium?

Jacqueline Lee

Enthalpy is a state property because its value is not dependent on the path taken to obtain that state. The best way that I can think of to describe it would be to look at this graph https://upload.wikimedia.org/wikipedia/commons/thumb/2/24/Activation_energy.svg/360px-Activation_energy.svg.png"oncli...

Jacqueline Lee

Before you take the log of a number, does the number have to equal to the number of Sig figs at the beginning of the problem(what was given) in order for the final value to be correct?

Jacqueline Lee

So in the course reader it says that oxoacids lose H+ more readily if the resulting anion can be stabilized by electron withdrawing atoms. I know from lecture that hypochlorous acid is stronger than hypoiodous acid because chlorine is more electron negative compared to iodone, but I dont' understand...

Jacqueline Lee

If heat is applied to an exothermic reaction, the reaction will reach equilibrium by shifting to the left. How Dr. Lavelle explained it during lecture was that if a reaction loses energy to form products(reactants -> products), the reverse reaction would use up energy(products -> reactants). In othe...

Jacqueline Lee

I believe we would put the s-orbital electron to the d-orbital when there is about to be 5 or 10 in the d-orbital.

That's why chromium's electron configuration is [Ar] 3d⁵4s instead of [Ar]3d⁴4s²
And copper's electrom configuration is [Ar]3d¹⁰4s and not [Ar]3d⁹4s²

Jacqueline Lee

image.jpeg From that example, when writing the electron configurations for O 2 - and N 2 , would we need to specify whether it's 2px, 2py, and 2pz on the quizzes or is that optional? If we do, how to we know what order the 2px/y/z are in or is it just by ascending order? Also, isn't the N 2 MO supp...

Jacqueline Lee

We can describe stability of a molecule with bond order. Bond order can be found by (# of electron in bonding molecular orbital - # of electron in anti-bonding molecular orbitals) divided by two. Anything above 0 means it would be stable, but the bigger the number you get for bond order would mean t...

Jacqueline Lee

From the discussion I had today, if the lone pairs were directly 180 degrees away from each other, that makes all lone pair-central atom-bonded atom angles 90 degrees. Whereas if you had the lone pairs next to each other (120 degrees away from each other), there would be 2 bonded atoms that are 90 d...

Jacqueline Lee

Can someone explain to me how distorted electrons work? Is it just the bigger atom drawing the electron from the smaller atom closer to the bigger atom? How is this considered a covalent character?

Jacqueline Lee

What works for me is I usually see what is given, and what the question is asking for. From there, if the formula used to find what they're looking for doesn't correspond to what was given, I look at what can be found with what was given (ex. given wavelength, I can find frequency).

Jacqueline Lee

If there is a multistep problem, do we maintain four significant figures per step, even for the following step? For example, if part A requires an answer with only four significant figures (example: 1.178), and part B uses that answer to solve for another variable, should we use 1.178 or the extend...

CHEMISTRY COMMUNITY

Search found 21 matches

Re: 2013 winter Q3

Re: 2009 final 4E

Staggered Conformations vs Eclipsed

Naming Compounds Clarification

Practice Quiz winter 2015

Re: Question About Variations of the Nernst Equ.

Question About Variations of the Nernst Equ.

Balancing Redox Reactions

Re: Calculating final temperature of a substance

Reversible and Irreversible Proccesses

Re: Enthalpy

Re: SigFigs

Question on Oxoacids

Re: Endo vs. Exothermic

Re: Electron Transfer in Configurations

Re: Bond Order and Stability

Re: #5 on the first quiz 2 preparation

Re: Lone Pair Repulsion for T-shape

Question about Distorted Electrons

Re: Equations

Re: All students read this sig fig post [ENDORSED]