CHEMISTRY COMMUNITY

Michelle_Li_1H

For this question we are asked to find the rate law and determine the rate constant given a set of data and the reaction: 2ClO (g) + O2 (g) ---> 2ClO2 (g) When we're setting up the rate law, rate= k[ClO]^n * [O2]^m, would we include the coefficient of the ClO? Or is that already accounted for when w...

Michelle_Li_1H

Is the final more geared towards information covered after the midterm? Or will it focus equally on both halves of the quarter? Dr. Lavelle previously replied to a similar question stating that the final will be fairly evenly distributed based on how long each section was covered. "We will spe...

Michelle_Li_1H

The overall equation of the reaction would be 1/2(O2) + O2 ---> O3, not looking at the catalysts or intermediates because they appear as both reactants and products and are therefore used up. The catalyst in this case would be NO because it is there from the beginning of the reaction, rather than be...

Michelle_Li_1H

To add on, both constitutional isomers and geometric isomers have the same molecular formula. However, constitutional formulas have different connectivity such that they can be drawn differently. Geometric isomers on the other hand have the same connectivity but different arrangements in space which...

Michelle_Li_1H

Hi, Even after reading the previous couple posts, I am still confused as to how we would identify the ambient nucleophile. I was wondering if someone could clarify what it is and how we would approach a problem that asks us to identify one. This is problem 4.6 in the OChem textbook: Identify the amb...

Michelle_Li_1H

I think it will cover the last half of kinetics, that wasn't covered in Quiz 2, along with the OChem that we've been covering. (Ch. 4 and Ch. 1)

Michelle_Li_1H

Hi! That K would be the equilibrium constant, which would equal to the concentration of the products over the concentration of the reactants. The purpose is to find an equation that relates the intermediate or in this case [N2O2] with [NO]^2. We would do so by treating the first step as if it were a...

Michelle_Li_1H

To add on to that, For part a, using the given mass of H2 and I2, you would divide by the molar mass to get the moles of H2 and I2. Then you would calculate the molarity of each using c=m/V. Given the rate constant and the fact that both reactants are first order, we would plug in the concentrations...

Michelle_Li_1H

Dr. Lavelle mentioned in another post that we should continue to bring the course reader but the OChem textbook is only for additional readings and assigned problems.

Hope this helps!

Michelle_Li_1H

Hi! The half life of the reaction is the time it takes for the reaction to reach half the initial concentration. For the case of the zeroth order reaction, the integrated rate law is [A]=-kt + [A]o. Therefore the equation for the half life of this zeroth order reaction would mean the concentration o...

Michelle_Li_1H

Hi! I think you might have read the solution manual wrong, but to approach the question, we would split the redox equation into two half equations. P4---> H2PO2- and P4---> PH3 Then to balance in a basic solution, we would first balance out the oxygen atoms then use OH- rather than H+ when balancing...

Michelle_Li_1H

Will the Feb. 10 review session by Dr. Lavelle be podcasted like last quarter?

Michelle_Li_1H

If you break down the redox reaction equation into the half reactions, then you'll get 2Ce^4+ --> 2Ce^3+ On the left hand side, the charge will be 8+, while the right will be 6+. To get a balanced half reaction, you'll have to add 2 moles of e- to the left hand side, which is where the 2 moles in yo...

Michelle_Li_1H

Because there is a temperature change, to calculate the change in entropy, you would use the equation n*Cp*ln(T2/T1) for part (a). n in this case would be 1 mol, while the the Cp would be 5/2*R, which would be 5/2*(8.314 J/K*mol). Lastly, you would convert the temperature to K and take the natural l...

Michelle_Li_1H

Simply put, the first equation with P*deltaV would be used when there is a constant pressure, whereas the second equation would be used with a variable pressure or when there is an isothermal expansion (no change in temperature and the change in volume is expanding).

Michelle_Li_1H

Question: Use data in Table 8.3 or Appendix 2A to calculate the entropy change for (a) the freezing of 1.00 mol H2O(l) at 0.00 C

I was wondering how I should approach this. Thanks in advance!

Michelle_Li_1H

Work is equal to -P multiplied by the change in volume. The equation for volume is area of the base times the height. In this case the distance that the pump has moved would equal to the height, therefore the work would equal to -P*A*d. However, because the units are given in cm, we would convert to...

Michelle_Li_1H

You are correct by calculating the standard enthalpy of formation of the products and subtracting the standard enthalpy of formation of the reactants. However, as we went over in class, the standard enthalpy of formation of an element in its most stable form is zero. In this case, the most stable fo...

Michelle_Li_1H

The booklet of practice midterms and finals was offered for an additional charge at the store, however the end of the course reader also has some practice exams.

Michelle_Li_1H

No, Kp was given. The solution includes Q to find the direction in which the reaction proceeds. However because the question doesn't explicitly state to solve for Q, I was wondering if it was necessary.

Michelle_Li_1H

Given: N2O4 (g) \rightleftharpoons NO2 (g) What are the equilibrium partial pressures of N2O4 and NO2 when 0.20 mol of N2O4 and 0.80 mol of NO2 are sealed in a 2.00 L container at 100 degrees Celsius. When the reaction reaches equilibrium at 100 degrees Celsius, Kp= 11.0. The solution in the book ca...

Michelle_Li_1H

Hi,

When drawing molecular orbital diagrams, I was wondering when and why the molecular orbital would be below the atomic orbital? Thanks!

Michelle_Li_1H

The podcasts (audio) definitely work for iPad and iPhone, but I haven't tried out the Webcasts yet.

Michelle_Li_1H

For the following reaction, if initially 0.100 mol of H2O (g) is placed in a 4.0 L vessel, what is the equilibrium partial pressures of each reactant and of each product? H2O (g) + C(s) <-> H2 (g) + CO (g) Kp = 3.72 at 1000 K For the question stated above, I found the molarity for H 2 O, 0.025 M, an...

Michelle_Li_1H

Hi,
I was wondering if there was a difference between cyanido and cyano? The book uses cyanido while the course reader uses cyano. Would it be wrong if we used one instead of the other? Thanks!

Michelle_Li_1H

Hi,

I was wondering how you would go about finding the oxidation numbers for more complicated compounds, such as [Co(CN)₅(OH)₂)]^2- ? Thanks!

Michelle_Li_1H

Hi,

I was wondering when you would know to draw the sigma 2p orbital above the pi 2p orbital or below it for the molecular orbital energy-level diagram?

Thanks!

Michelle_Li_1H

Hi,

I was wondering, for questions that ask you to arrange the ions according to bond length, is it necessary to draw out the Lewis Dot Structure (to find out whether it is single, double, or triple bond and compare)? Or is there another method?

Thanks!

Michelle_Li_1H

Hi,

Does anyone happen to know how to go about solving these problems though? What do the sigma and pi bonds mean in terms of the bonds? Thanks!

Michelle_Li_1H

Hi,

Regarding the ratio, I got 1:4.5:1 for C, H, and O respectively. However, I was wondering how you would know to round down to 4 for H instead of multiplying the entire thing by 2 to get a whole number for H? Thanks!

Michelle_Li_1H

Hi,

I was reading through Chapter 1 and saw that the book included an expanded version of the Schrodinger equation ( $-\frac{hbar^2}{2m}* \frac{d^2\Psi }{dx^2} + V(x)\Psi = E\Psi$ ). I was wondering what this meant and if we needed to know it for quizzes or exams?

Thanks!

Michelle_Li_1H

For the first part of the question regarding the photoelectric effect, I believe when the energy of the photon is greater than or equal to the energy binding together the specific atom and the electron, then one photon will interact with one atom to eject one electron.

CHEMISTRY COMMUNITY

Search found 32 matches

Winter 2016 Q4

Re: Final Exam Details and Review Sessions Winter 2017

Re: Lecture Example: Homogeneous Catalyst

Re: Geometric vs Constitutional Isomers [ENDORSED]

Ambient Nucleophiles

Re: Quiz 3

Re: K=...? (pg 73 course reader pre-equilibrium ex)

Re: 15.13 Homework Question

Re: Intro to Organic Chemistry

Re: Zero Order Half-Life Relationship

Re: Balancing 14.5 part d

Re: Midterm Winter 2017

Re: example 14.9

Re: Ch. 9 #7 HW

Re: work

Homework Question 9.15 (a)

Re: Problem Three Part A

Re: Homework 8.59

Re: Quiz Practice

Re: 2007 Final Question 5B

2007 Final Question 5B

Drawing Molecular Orbital Diagrams

Re: Bruincast

Quiz 3 Prep Fall 2014 #10

Naming CN-

Re: Number 29 from the Hw [ENDORSED]

Re: Anti bonding Orbitals

Arranging Ions According to Bond Length

Re: Sigma and Pi Bonds for Quiz 2

Re: Fall 2015 Quiz Prep question #5 [ENDORSED]

Expansion of Shrodinger Equation [ENDORSED]

Re: 1:1:1 ratio