## Search found 19 matches

Mon Mar 07, 2016 10:39 am
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Torsional Strain
Replies: 1
Views: 304

### Re: Torsional Strain

Torsional strain occurs when rotating a molecule around a bond and is due to the repulsion caused by electrons in between different groups when they pass each other. Torsional strain increases a molecule's potential energy.
Mon Feb 29, 2016 10:34 am
Forum: *Complex Reaction Coordinate Diagrams
Topic: Reaction Profile Delta G
Replies: 4
Views: 1198

### Re: Reaction Profile Delta G

I believe that when you're trying to measure which transition state has a larger delta G, you would compare TS1 with the free energy of the reactants and then TS2 with the free energy of the intermediates, or the pseudo-equilibrium between TS1 and TS2. However, I'm not sure why this is the case eith...
Tue Feb 23, 2016 5:37 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: 4.30
Replies: 1
Views: 347

### Re: 4.30

You would solve this problem using the equation k= A exp(-EA/RT). You would just plug in the values for the activation energy and for room temperature (298K) and if you obtained a positive k value, the reaction would occur at room temperature.
Mon Feb 15, 2016 10:16 pm
Forum: Second Order Reactions
Topic: Graph of Second Order Reactions
Replies: 1
Views: 309

### Re: Graph of Second Order Reactions

Given the graph of a second order reaction, you would just calculate the rate constant by calculating the slope of the line. The slope of the line for a second order reaction is equal to k, the rate constant.
Mon Feb 08, 2016 5:20 pm
Forum: Balancing Redox Reactions
Topic: 2009 Mid term #7
Replies: 1
Views: 338

### Re: 2009 Mid term #7

The steps to balance redox reactions under acidic and basic conditions differ slightly, but to balance a redox reaction under acidic conditions, you must first balance all elements except O and H. Next, you add H2O to balance the O's and then you add H+ to balance the H's. You then add electrons to ...
Mon Feb 01, 2016 5:08 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: E° at Equilibrium
Replies: 1
Views: 375

### Re: E° at Equilibrium

E° is zero at equilibrium because the cell potential, E°, is a measure of the potential difference between the anode and the cathode, which is caused by the ability of electrons to flow from one to the other. At equilibrium, since the two solutions are equal, there would be no potential difference b...
Mon Jan 25, 2016 6:22 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Quiz 1 Preparation Winter 2015 #3
Replies: 1
Views: 306

### Re: Quiz 1 Preparation Winter 2015 #3

Since you know that the ideal gas expands isothermally and reversibly, you know that delta U is 0, and therefore q= -w. The equation for w would be w= -nRT ln(Vfinal/Vinitial) since the temperature is constant, and so after you find the value for w, you would use q= -w to find the value for q.
Tue Jan 19, 2016 10:56 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated System after 100 years
Replies: 2
Views: 763

### Re: Isolated System after 100 years

Delta U would equal 0 kJ since there would be no change in internal energy in an isolated system, as U final would be +5 kJ and U initial would also be +5 kJ.
Tue Jan 12, 2016 12:40 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Example in Course Reader Specific Heat
Replies: 2
Views: 311

### Re: Example in Course Reader Specific Heat

You multiply the 1 g/mL by 100 mL because you are given a specific heat capacity in units of J.°C^-1.g^-1. In order to have your units cancel out and end up with the desired units of kJ, you must multiple the 1g/mL by 100 mL in order to get a unit of g for the mass of the solution.
Wed Jan 06, 2016 11:29 am
Forum: Phase Changes & Related Calculations
Topic: Vaporization Heat Transfer
Replies: 3
Views: 677

### Re: Vaporization Heat Transfer

Vaporization is an endothermic process because energy is used to break the bonds in order to transform a liquid into a gas. Also, the particles gain energy going from a liquid to a gas.
Tue Dec 01, 2015 8:42 pm
Forum: *Titrations & Titration Calculations
Topic: HW 13.23
Replies: 3
Views: 518

### HW 13.23

For part A of this problem, it asks you to sketch the titration curve for the titration of 5.00 mL .010 M NaOH with 0.005 M HCl and to indicate the pH of the initial and final solutions, as well as the pH at the stoichiometric point. I understand how to calculate the pH of the initial solution and t...
Sun Nov 29, 2015 12:46 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Fundementals J15 NaC6H5O is acid/base?
Replies: 4
Views: 2340

### Re: Fundementals J15 NaC6H5O is acid/base?

In the question, it states that either the cation or anion of the salt is a weak acid or a weak base. The anion of NaC6H5O is C6H5O-, which is a weak acid. You use this anion when writing the equation for the proton transfer with water.
Tue Nov 17, 2015 10:43 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Oxidation Number
Replies: 1
Views: 309

### Re: Oxidation Number

Yes. When there's a different ligand outside of the coordination sphere, you also have to take the charge of that ligand into account when finding the oxidation number of the central metal atom.
Fri Nov 13, 2015 9:22 am
Forum: Naming
Topic: Naming of Coordination Compounds
Replies: 2
Views: 254

### Re: Naming of Coordination Compounds

You use the name iron when the complex has an overall neutral charge, but you use "ferrate" when the complex is anionic with an overall negative charge.
Fri Nov 06, 2015 3:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AX2E3
Replies: 2
Views: 492

### Re: AX2E3

I think that the AX2E3 shape would be linear because although it has lone pairs on it, the three lone pairs are arranged in such a way that the lone pairs and their repulsions cancel each other out (so to speak) and therefore don't cause the atoms bonded to the central atom to move closer together. ...
Mon Oct 26, 2015 4:06 pm
Forum: Lewis Structures
Topic: Double Bonds
Replies: 1
Views: 291

### Re: Double Bonds

We know when to form double bonds by checking the formal charges of atoms. If adding a double bond rather than just a lone pair makes the formal charge of the atom closer to zero, then we add a double bond.
Tue Oct 20, 2015 11:37 pm
Forum: Lewis Structures
Topic: Lewis Structures
Replies: 2
Views: 310

### Re: Lewis Structures

Electron arrangement takes into account the lone pairs and the atoms surrounding the central atom, while molecular structure/shape only takes into account the atoms surrounding the central atom. If a compound is AX 3 E (which would be 3 bonded pairs and one lone pair), then yes, the electron arrange...
Thu Oct 15, 2015 12:26 am
Forum: Trends in The Periodic Table
Topic: Homework 2.37 b
Replies: 1
Views: 457

### Re: Homework 2.37 b

The s orbital has a greater electron probability density in the nucleus than other orbitals, so yes, penetrate refers to the fact that the s orbital is essentially closer to the nucleus. Since an electron in the s orbital can more effectively penetrate the nucleus of an atom than electrons in other ...
Tue Oct 06, 2015 11:05 pm
Forum: Properties of Electrons
Topic: Diffraction Patterns
Replies: 1
Views: 307

### Diffraction Patterns

Do interacting waves give rise to diffraction patterns?