Search found 22 matches

by Dan Dinh 3K
Fri Mar 11, 2016 12:33 pm
Forum: *Alkanes
Topic: Angles
Replies: 2
Views: 322

Re: Angles

The way you draw the structure would matter if there were a double bond. You would need to draw it so that the highest priority groups are in the designated Z/E position.
by Dan Dinh 3K
Sun Mar 06, 2016 1:59 am
Forum: *Alkanes
Topic: Naming is Confusing
Replies: 1
Views: 246

Re: Naming is Confusing

I don't think atomic number has anything to do with naming? It is always alphabetical. You might be thinking about E/Z geometric isomers in which you decide the what your priority groups are depending on the part that has the highest atomic number on each carbon.
by Dan Dinh 3K
Sat Feb 27, 2016 5:44 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Psuedo-Equilibrium Constant
Replies: 1
Views: 228

Psuedo-Equilibrium Constant

Is it possible to obtain the actual equilibrium constant from the pseudo-equilibrium constant obtained through the activated complex? What does this reveal about the reaction? Would delta G of the exergonic reaction be negative with a large K‡?
by Dan Dinh 3K
Fri Feb 19, 2016 12:05 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: Unit of rate constant
Replies: 2
Views: 1185

Re: Unit of rate constant

You would have to derive it depending on what order your reaction is. You can either cancel out units when solving for the rate constant or you can just memorize it. For a zero order reaction, the rate constant unit is M/s. For a first order reaction, the rate constant unit is 1/s. For a second orde...
by Dan Dinh 3K
Tue Feb 09, 2016 12:13 am
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Avogadro's Number and Residual Entropy
Replies: 1
Views: 388

Avogadro's Number and Residual Entropy

When do you need to multiple the equation, S = Kbln(W) by avogadro's number? For example, in the 2012 midterm, on question 3A, you don't need to. Is this because it is asking for the residual entropy for the entire molecule?
by Dan Dinh 3K
Fri Feb 05, 2016 7:42 pm
Forum: Balancing Redox Reactions
Topic: Balancing Redox Rxn in Basic Solution
Replies: 1
Views: 255

Re: Balancing Redox Rxn in Basic Solution

In a basic solution, there should be OH- present instead of H+ ions. Therefore, you would balance the half reaction the same way as you would in an acidic solution. Then, you would have to add as much OH- to both sides of the equation as you would need in order to cancel out the H+ if it is still pr...
by Dan Dinh 3K
Tue Jan 26, 2016 12:39 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Different Values for G of Formation
Replies: 1
Views: 217

Different Values for G of Formation

There are multiple ways of calculating delta G for a reaction. For example, products minus reactants versus delta h minus temperature times delta H. Sometimes the values that I get are vastly different (for example: -753.01 kJ/mol vs. -713.02 kJ./mol). Is there a correct way to calculate it in this ...
by Dan Dinh 3K
Sun Jan 24, 2016 8:55 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Increasing Entropy
Replies: 1
Views: 438

Re: Increasing Entropy

The entropy of container A has more entropy because of its monatomic gas, meaning that there are more particles in the container versus a container with diatomic gas. With more particles, there is more disorder.
by Dan Dinh 3K
Mon Jan 18, 2016 3:54 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Homework Problem 8.53, Different Equation for Q value
Replies: 1
Views: 322

Homework Problem 8.53, Different Equation for Q value

On this problem, how do you know to use q = -CdeltaT instead of the regular q=mcdeltaT equation?
by Dan Dinh 3K
Sun Jan 17, 2016 9:19 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 3/2 and 5/2 R
Replies: 5
Views: 1556

Re: 3/2 and 5/2 R

If the ideal gas is at constant volume then you use 3/2R and if the ideal gas is at constant pressure then you use 5/2R.
by Dan Dinh 3K
Fri Jan 08, 2016 9:35 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Constant Volume and Pressure
Replies: 1
Views: 258

Constant Volume and Pressure

Does a calorimeter with a constant volume vs. a calorimeter with a constant pressure result in different heat capacities? Does a coffee cup calorimeter or bomb calorimeter both take into account constant pressure/volume?
by Dan Dinh 3K
Tue Dec 01, 2015 8:51 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Electronegativity in Strength of Acids
Replies: 1
Views: 292

Electronegativity in Strength of Acids

I understand that elements with a higher electronegativity pull the electrons closer, making it easier for the hydrogen to dissociate; however, why is HF a weak acid if fluorine is the most electronegative element? What is more important in determining the comparative strength of acids, bond strengt...
by Dan Dinh 3K
Thu Nov 26, 2015 1:32 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Solids and Water Vapor
Replies: 2
Views: 317

Solids and Water Vapor

How do adding solids affect equilibrium? Does Le Chatelier's principle only pertain to concentration or does it also include pressure? Is the pressure of water vapor ever changed?
by Dan Dinh 3K
Fri Nov 20, 2015 9:25 am
Forum: Determining Molecular Shape (VSEPR)
Topic: T-Shaped Molecule and its Dipole Moments
Replies: 3
Views: 1123

Re: T-Shaped Molecule and its Dipole Moments

Then why is an AX2E3 structure 180 degrees and linear?
by Dan Dinh 3K
Thu Nov 19, 2015 8:17 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: T-Shaped Molecule and its Dipole Moments
Replies: 3
Views: 1123

T-Shaped Molecule and its Dipole Moments

Do t-shaped molecule's dipole moments cancel out? Also, when you remove lone pairs from a trigonal bipyramidal shaped molecule or 3 from an octahedral shaped molecule, is the t-shape the same? Are the angles both 180 and 90 or is it distorted due to the presence of the lone pairs?
by Dan Dinh 3K
Fri Nov 13, 2015 5:20 pm
Forum: Lewis Acids & Bases
Topic: Strong acids/bases
Replies: 3
Views: 560

Re: Strong acids/bases

Yes, you would have to memorize them. There are quite a few, but if you work through enough problems they should get familiar. Strong acids would be HI, HNO 3 , HCl, HBr, HIO 3 , HClO 4 , HClO , and H 2 SO 4 . The rest are usually weak, especially if you see that it is an organic compound such as ac...
by Dan Dinh 3K
Tue Nov 03, 2015 6:01 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Order
Replies: 5
Views: 1607

Re: Bond Order

Hi Michelle, I was wondering that too. Does a 1.5 bond order number mean that a molecule has resonance, thus contributing to a more stable structure? Therefore, would a 1.5 bond order mean that it is more stable than a bond order of 1 since its resonance contributes to its stability? I know I just a...
by Dan Dinh 3K
Fri Oct 30, 2015 7:15 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Can individual atoms be ligands?
Replies: 3
Views: 370

Re: Can individual atoms be ligands?

Yes, I believe the chlorine would be a ligand in this case. A ligand is just an ion or molecule attached to a metal atom to form a complex by coordination bonding and if its in the brackets, that means it is in the coordination sphere.
by Dan Dinh 3K
Sat Oct 24, 2015 3:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw Bond Angles
Replies: 6
Views: 6991

Seesaw Bond Angles

I know that for a seesaw shape, it originates from the trigonal bipyramidal shape. Where do you put the lone pair and why? Also, does this affect the bond angles for seesaw, because my TA said it would still be 90 degrees and 120 degrees?
by Dan Dinh 3K
Fri Oct 16, 2015 3:16 am
Forum: Resonance Structures
Topic: Stability in Resonance Structures
Replies: 1
Views: 327

Stability in Resonance Structures

I was wondering what makes resonance structures more stable than molecules without resonance? What are some ways that researchers have used the stability of resonance structures to their advantage?
by Dan Dinh 3K
Thu Oct 08, 2015 10:36 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation
Replies: 2
Views: 400

Rydberg Equation

After using the equation E = -hR/n^2 to obtain the energy that is released when an electron transitions from the different energy levels, I was wondering if I could then use that same energy into the E=hv equation. Is delta E different in this case? This question pertains to the Quiz Preparation Pro...
by Dan Dinh 3K
Thu Oct 01, 2015 1:56 am
Forum: DeBroglie Equation
Topic: Cutoff to Determine Wavelike Properties
Replies: 2
Views: 475

Cutoff to Determine Wavelike Properties

Hello, In class, I know we looked at different examples using the De Broglie wavelength equation and I understand that it occurs with a small mass and high velocity. What is the cutoff is between something having wavelengths that could be experimentally detected in a lab and not? Why is this importa...

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