CHEMISTRY COMMUNITY

Katie Clark 3B

How do you determine what n is in the Nernst equation? For example, if you had the equation 2Cr³⁺ + 3HClO₂ + 4H₂0 -> CrO₇^2- + 3HClO + 8H⁺ , how would you determine what to use for n in the equation E= E_standard - (.05916V)/n logQ

Katie Clark 3B

For the various conformations (butterfly, envelope, chair, and boat), how do you know which axial bonds are up or down? I know that it alternates which up and down and does the same for equatorial. I'm wondering where you should start the axial up. For example, on the envelope conformation, how do y...

Katie Clark 3B

In problem 20 of chapter 2 in the organic chemistry textbook, they ask to draw 2-methyl-2-butanol and then name what type of alcohol it is. The answer given is tertiary alcohol? How do you know it is tertiary? How can you tell?

Katie Clark 3B

Can someone describe the basic structure of a substituent with the common name prefix sec-? I was not able to copy down the different structures that the guest lecturer showed on her powerpoint with the sec- structures on it. Or could you tell me where I would find this information in the textbook?

Katie Clark 3B

I'm wondering when the sign of standard E changes. On question 8 on the midterm, the oxidation half reaction was Cd->Cd 2+ + 2e - . In the formula sheets we are given, the standard E=-0.40 V for Cd 2+ +2e - ->Cd. However, in the answer key, the standard E for the half reaction is 0.40 V. Why is this?

Katie Clark 3B

How do you solve for time given k and the concentrations. For example, in the Winter 2014 Quiz 2 Prep #9, the question is: A reaction has k=8.39 M^-1s^-1. How long does it take for the reactant concentration to drop from 0.0840 M to 0.0220 M?

Katie Clark 3B

Can someone explain what potential difference actually is? Not the formula, but the definition. And what is the difference between potential difference and cell potential?

Katie Clark 3B

Can someone explain what the electromotive force is? And what is its relation to the maximum potential difference?

Katie Clark 3B

On the homework problem 8.51, the reaction is 4C 7 H 5 N 3 O 6 +21O 2 -> 28CO 2 + 10H 2 O+6N 2 . It is also given that the enthalpy of formation for TNT is -67 kJ per mol. Can someone explain why the solutions manual only used the enthalpies of formation for TNT, H 2 O and CO 2 to find the enthalpy ...

Katie Clark 3B

For quiz #1, what topics will be covered? More specifically which lectures will be covered on the quiz?

Katie Clark 3B

Why is there a negative in the work equation w=-PΔV?

Katie Clark 3B

What is the difference between heat capacity, specific heat capacity, and molar heat capacity?

Katie Clark 3B

I couldn't understand how to solve for the final pH of the final solution in a titration. For example, in problem 13.23, the question is, what is the pH of the final solution for the titration of 5.00 mL 0.010 M NaOH with 0.005 M HCl. In the problem, we also had to find the initial pH and the pH at ...

Katie Clark 3B

When calculating the pH and pOH of 0.057 M NH 3 , I am confused about an approximation that the solution manual made when solving for x in the K b equation. The chemical equation was NH 3(aq) +H 2 0 (l) =NH 4(aq) + +OH - (aq) . I did an ice box and had that K b =x 2 /...

Katie Clark 3B

Can someone explain the difference between the Lewis definition and Brosted definition for acids and bases?

Katie Clark 3B

So if there the complex only had one (en), would the name still contain bis- since (en) is polydentate?

Katie Clark 3B

For potassium tetracyanonickelate (II), could someone explain where you incorporate the oxidation number when writing the formula. The answers never include a charge on the coordination complex which confuses me since we often write the names of these complexes and they were given to us with a negat...

Katie Clark 3B

Can someone explain to me why the name of [Cr(en) 2 (H 2 O)Cl]Cl 2 is aquachlorobis(ethylenediamine)chromium (III) chloride. I understand all of it except the bis(ethylenediamine) part. I know that the bis- is there because ethylenediamine is bidentate. But what I don't understand is why there isn't...

Katie Clark 3B

You put it in alphabetical order using the A in aqua.

Katie Clark 3B

Can someone explain to me how to determine if a ligand is polydentate just by looking at its molecular formula? I am not sure how to identify them unless I write out the lewis structure. For example, HN(CH₂CH₂NH₂)₂.

Katie Clark 3B

Use the molecular orbital diagram for whichever atom has the lower atomic number. For example if you had CO, you would use the molecular orbital diagram for Z<8 since carbon has an atomic number less than 8.

Katie Clark 3B

Can someone explain how to determine which bond has a greater dissociation energy? For example, which has a greater dissociation energy, O-H or S-H?

Katie Clark 3B

I am confused as to why the shape of the molecule I 3 - is linear. I got the correct Lewis structure for the molecule. The central atom had five regions of electron density. Why then is the shape linear? Wouldn't the three lone pairs of electrons affect the shape? Could someone please explain this t...

Katie Clark 3B

I have reworked question 10 and still cannot get the correct answer. The question reads, "If molybdenum is irradiated with light of wavelength of 294 nm, what is the maximum possible kinetic energy of the emitted electrons?". I got the correct answer for the first part of the question, &qu...

Katie Clark 3B

I solved for the frequency using the given wavelength. I then pugged that value and n=1 into the equation from the book: \nu =R(\frac{1}{n_{f}^{2}}-\frac{1}{n_{i}^{2}}) . I plugged in n=1 to the first n in the equation. I then solved for the second n and found it to be equal to 3. Hope this ...

Katie Clark 3B

I have the Fall 2015 course reader for Chem 14A with Lavelle. On page 46 there is a worked example. The question is: "Calculate the frequency of light emitted by a hydrogen atom when an electron makes a transition from the fourth to the second principal quantum level." I understand how the...

CHEMISTRY COMMUNITY

Search found 26 matches

Determining n in nernst equation

Determining direction of axial and equatorial bonds

Types of alcohols

Sec- structure

Sign for Standard Reduction Potentials

How to solve for time, given k and concentrations

Potential difference vs. cell potential

Electromotive force

How to find enthalpy of rxn using enthalpies of formation?

Quiz #1

Work equation

Different heat capacities

Find the final pH of the final solution in a titration

Solving for x in Problem 12.59 a

Lewis vs. bronsted

Re: Naming complexes

Writing chemical formulas

Naming complexes

Re: Naming Coordinate Compounds

Determining if a ligand is polydentate

Re: Molecular Orbital Theory

Dissociation energy

Confusion on Homework Problem 4.13 Part A

Question 10 on Quiz 1 Preparation Fall 2013 in the Workbook

Re: Atomic Spectra Chapter 1 #15 HW problem

Confusion on Worked Example in Course Reader