Search found 22 matches
- Thu Mar 10, 2016 9:43 pm
- Forum: *Electrophilic Addition
- Topic: The Number of Intermediates for Electrophilic Addition
- Replies: 3
- Views: 754
The Number of Intermediates for Electrophilic Addition
For the reaction profile of an electrophilic addition reaction, there are two peaks for the two steps/two transition states, and one trough in the graph. I thought this single trough means there is only one intermediate, but for electrophilic addition, there are always two intermediates? Why does th...
- Sat Mar 05, 2016 4:16 pm
- Forum: *Ketones
- Topic: HW 2.27 Numbering the Carbons
- Replies: 1
- Views: 1323
HW 2.27 Numbering the Carbons
2.27 asks to draw a structure of 2,2-dimethyl-3-pentanone. I was wondering why it is numbered as 2,2-dimethyl-3-pentanone instead of 4,4-dimethyl-3-pentanone since the functional group is given the priority (so pentanone should have a lesser number than the methyls)?
Thank you in advanced!
Thank you in advanced!
- Sat Feb 27, 2016 3:47 pm
- Forum: *Alcohols
- Topic: Why 4-chloro-3-butanol?
- Replies: 2
- Views: 693
Why 4-chloro-3-butanol?
I was confused with this last example in lecture on Friday with ClCh2Ch2CHOHCH3 (the OH on the third carbon to the right). Why is it butanol? If the functional group carbon is #1 then isn't it propanol?
Thank you in advanced!
Thank you in advanced!
- Sun Feb 07, 2016 10:07 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: 14.55 How to determine the anode
- Replies: 1
- Views: 731
14.55 How to determine the anode
14.55 A 1.0 m NiSO4(aq) solution was electrolyzed by using inert electrodes. Write (a) the cathode reaction; (b) the anode reaction. (c) With no overpotential or passivity at the electrodes, what is the minimum potential that must be supplied to the cell for the onset of electrolysis? How come in th...
- Wed Feb 03, 2016 10:25 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: G(naught) vs G
- Replies: 1
- Views: 510
Re: G(naught) vs G
deltaG is zero when the reaction is at equilibrium. deltaG(naught) is zero when K = 1 because since deltaG(naught) = -RTlnK, when K =1, then lnK = 0, and deltaG(naught) = 0.
- Mon Jan 25, 2016 3:33 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: 9.83 Homework Problem: using volume to find concentration
- Replies: 3
- Views: 3514
9.83 Homework Problem: using volume to find concentration
9.83 Hydrogen burns in an atmosphere of bromine gas to give hydrogen bromide gas. (a) What is the standard Gibbs free energy of the reaction H2(g) Br2(g) S 2 HBr(g) at 298 K? (b) If 120. mL of H2 gas at STP combines with a stoichiometric amount of bromine and the resulting hydrogen bromide dissolves...
- Sun Jan 24, 2016 3:20 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Knowing when a value is equal to zero
- Replies: 2
- Views: 594
Re: Knowing when a value is equal to zero
Why isn't delta S surr also zero since it is also a state function?
- Sat Jan 23, 2016 7:57 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Homework 9.47 Isothermal/Expansion Problem
- Replies: 1
- Views: 3587
Homework 9.47 Isothermal/Expansion Problem
9.47 Initially a sample of ideal gas at 323 K occupies 1.67 L at 4.95 atm. The gas is allowed to expand to 7.33 L by two pathways: (a) isothermal, reversible expansion; (b) isothermal, irreversible free expansion. Calculate Stot, S, and Ssurr for each pathway. I solved for the number of moles, n, an...
- Wed Jan 20, 2016 8:20 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Concepts about Internal Energy and Entropy
- Replies: 1
- Views: 311
Concepts about Internal Energy and Entropy
Hello! I was hoping someone could clarify what we learned in lecture today about how internal energy has to be zero in order to figure out what makes a reaction favorable (entropy or enthalpy) and so that q equals -w. Why does internal energy have to be zero? And I am also a bit confused about what ...
- Mon Jan 11, 2016 7:30 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Using Volume of Solution for Calorimetry Calculations
- Replies: 1
- Views: 577
Using Volume of Solution for Calorimetry Calculations
Hello! Today in lecture, we went over the example with 50.0 mL of 1.0 M HCL and NaOH. We used the volume and density to find mass, but I was wondering why we cannot find the moles of water produced and then convert the moles to grams and then use q = g x Csp x change in temperature? Why do we need t...
- Sat Jan 09, 2016 7:48 pm
- Forum: Phase Changes & Related Calculations
- Topic: Conditions for Standard Enthalpy
- Replies: 1
- Views: 468
Conditions for Standard Enthalpy
The standard conditions are 25 deg Celsius and 1 atm...how come there is no standard for volume? Is it because volume depends on the numbers of moles of a gas there are?
- Wed Dec 02, 2015 2:43 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: HW 13.97 Finding pH involving CaCO3 and HCl
- Replies: 1
- Views: 1010
HW 13.97 Finding pH involving CaCO3 and HCl
I need help figuring out how to do: 13.97 Two friends go to an all-you-can eat restaurant but eat a little too much and get heartburn. Both return to their rooms and look for a remedy. One friend takes two tablets, each containing 750 mg CaCO3, and the second friend takes 3 teaspoons of milk of magn...
- Mon Nov 30, 2015 10:30 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: What is K for 12.69.b?
- Replies: 1
- Views: 505
What is K for 12.69.b?
12.69 Calculate the pH of each of the following solutions:
(b) 0.055 m AlCl3(aq).
I am pretty sure Al3+ would be an acid...how do we know what K is when [Al(H2O)6]3+ is formed? (and how did we know that [Al(H2O)6]3+ formed and not some other compound like [Al(H2O)3]3+?
(b) 0.055 m AlCl3(aq).
I am pretty sure Al3+ would be an acid...how do we know what K is when [Al(H2O)6]3+ is formed? (and how did we know that [Al(H2O)6]3+ formed and not some other compound like [Al(H2O)3]3+?
- Sun Nov 29, 2015 11:04 pm
- Forum: Bronsted Acids & Bases
- Topic: HW 12.9.c is not a proton transfer?
- Replies: 2
- Views: 616
HW 12.9.c is not a proton transfer?
I need help putting to words why (c) CH3COOH(aq) + NH3(aq) -> CH3CONH2(aq) + H2O(l) is not considered a proton transfer? It doesn't "look" like it but I need help explaining. Thank you!
- Fri Nov 20, 2015 5:18 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Clarification on Acid/Base concepts
- Replies: 2
- Views: 660
Clarification on Acid/Base concepts
I had a few questions about the concept of acid and bases:
Does H3O+ actually have three hydrogens bonded to the oxygen, or is it just a H+ interacting with the H2O?
And, I think this might have been mentioned in class, but are Lewis acids/bases always Bronsted acids/bases?
Thank you!
Does H3O+ actually have three hydrogens bonded to the oxygen, or is it just a H+ interacting with the H2O?
And, I think this might have been mentioned in class, but are Lewis acids/bases always Bronsted acids/bases?
Thank you!
- Tue Nov 10, 2015 9:09 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: HW problem 11.7c: Calculate K given initial Pressure in bar
- Replies: 1
- Views: 367
HW problem 11.7c: Calculate K given initial Pressure in bar
For this problem, I made an ICE box using the equation X2 <-> 2X since the diatomic gas is becoming two "X"s. However, I keep on getting an answer different to the textbook...help please! Thank you!
- Mon Nov 02, 2015 7:33 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Comparing Equilibrium Concentrations
- Replies: 1
- Views: 339
Comparing Equilibrium Concentrations
In the equation N2 + 3H2 <-> 2NH3, how come the equilibrium concentration for hydrogen is not three times more than that of nitrogen? Are the equilibrium concentrations of the reactants and products in anyway related to each other through the coefficients?(ie. would equilibrium concentration of N2 b...
- Wed Oct 28, 2015 7:00 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Energy difference between 2s and 2p based on nuclear charge
- Replies: 1
- Views: 1439
Energy difference between 2s and 2p based on nuclear charge
Hello!
How come the energy difference between the 2s and 2p orbitals decreases as effective nuclear charge decreases? And how come when we "add" two 2s atomic orbitals we get a bonding sigma molecular orbital of lower energy rather than higher? Does it have to do with stability?
Thank you!
How come the energy difference between the 2s and 2p orbitals decreases as effective nuclear charge decreases? And how come when we "add" two 2s atomic orbitals we get a bonding sigma molecular orbital of lower energy rather than higher? Does it have to do with stability?
Thank you!
- Fri Oct 23, 2015 10:36 am
- Forum: Hybridization
- Topic: Textbook Problem 3.21C
- Replies: 1
- Views: 1674
Re: Textbook Problem 3.21C
Hello! Te has 6 valence electrons. (It is in the same group as oxygen.) However, Te^2- is an anion with two more electrons than the neutral Te. Therefore, it has 6 + 2 electrons or 8 electrons. This make Te^2- have the same configuration as the element two spaces next to Te (and thus, two electrons ...
- Wed Oct 14, 2015 6:34 pm
- Forum: Ionic & Covalent Bonds
- Topic: More than Octect
- Replies: 5
- Views: 1352
More than Octect
Hello,
Sulfur can have more than eight electrons because there are 3d orbitals available...so do the extra electrons on sulfur go into the 3d orbitals? I thought that we filled in the 4s orbital first?
Thank you!
Sulfur can have more than eight electrons because there are 3d orbitals available...so do the extra electrons on sulfur go into the 3d orbitals? I thought that we filled in the 4s orbital first?
Thank you!
- Wed Oct 07, 2015 9:03 am
- Forum: Quantum Numbers and The H-Atom
- Topic: Chapter 2, Problem 19, part A # of values for l
- Replies: 1
- Views: 511
Chapter 2, Problem 19, part A # of values for l
Hello! Can someone explain to me why the answer to this problem is seven? (2.19.a) "How many values of the quantum number l are possible when n =7? " I thought it would be four because in the seventh row, the electron can be in s, p, d, or f which is 0, 1, 2, 3...four possible values for q...
- Mon Sep 28, 2015 9:41 pm
- Forum: Properties of Light
- Topic: Hw 1.7
- Replies: 2
- Views: 647
Re: Hw 1.7
Hi, Kayla!
I also got 150 pm! For some reason, the back of the book says nm, but the problem even asks for pm, so I am pretty sure we are correct! :)
-Yoon
I also got 150 pm! For some reason, the back of the book says nm, but the problem even asks for pm, so I am pretty sure we are correct! :)
-Yoon