## Search found 19 matches

Sat Mar 05, 2016 2:59 pm
Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
Topic: Consitutional Isomers Question
Replies: 2
Views: 368

### Re: Consitutional Isomers Question

Constitutional isomers are compounds that have the same molecular formula and different connectivity, so yes as long as they still have the same formula.
Tue Mar 01, 2016 12:00 am
Forum: *Alkanes
Topic: Naming Given Structural Formula
Replies: 2
Views: 335

### Re: Naming Given Structural Formula

It helps to draw out the structure for the formula given. The ones in the parentheses are usually the substituents, but could also be the condensed formula, such as if it is (CH2)4.
Sat Feb 27, 2016 2:59 pm
Forum: *Alkanes
Topic: Iso
Replies: 2
Views: 374

### Re: Iso

Iso, neo, tert, and sec are all used as common names versus the regular IUPAC nomenclature.
Fri Feb 12, 2016 10:09 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Reaction rate
Replies: 3
Views: 525

### Re: Reaction rate

The rate would depend on the products, because in a reverse reaction, you're now putting the reactants in the products position.
Sun Feb 07, 2016 3:18 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 2010 Midterm Question #3 Part B
Replies: 1
Views: 312

### Re: 2010 Midterm Question #3 Part B

Even though the deltaU, q, and w are all zero, the deltaS of the system is not zero. Delta S of the surroundings would be zero, but to find the deltaS, you would use the formula dS=nRln(v2/v1) instead of q/T because the system is irreversible.
Tue Feb 02, 2016 12:22 pm
Forum: Balancing Redox Reactions
Topic: 14.3
Replies: 1
Views: 299

### Re: 14.3

Yes, when balancing redox reactions in an acidic solution, you use H+ to balance the hydrogens and H2O to balance the oxygens on each side. This is assumed, and isn't usually stated explicitly in the problem.
Sun Jan 31, 2016 4:40 pm
Forum: Balancing Redox Reactions
Topic: Standard Reduction Potentials
Replies: 2
Views: 419

### Re: Standard Reduction Potentials

This is because the standard reduction potential is an intensive property, which means that it doesn't depend on how many times the reaction occurs, but you still have to flip the sign when reversing the half reaction.
Sat Jan 23, 2016 1:13 pm
Forum: Phase Changes & Related Calculations
Topic: Converting
Replies: 2
Views: 299

### Re: Converting

I'm pretty sure that conversion is given to us on the equation sheet!
Sat Jan 16, 2016 3:25 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Changes in Volume
Replies: 2
Views: 426

### Re: Changes in Volume

Yes, the volumes of solids and liquids change negligibly in a closed/isolated system.
Sat Jan 09, 2016 2:31 pm
Forum: Phase Changes & Related Calculations
Topic: Hess's Law
Replies: 8
Views: 1049

### Re: Hess's Law

In the CR, when solving a problem using the Hess's Law method the two equations are presented in such a way where you can add the equations vertically, but he cancels out the reactants in one equation that appears in the product of the other, is this something that can always be done? Will there al...
Fri Dec 04, 2015 11:35 pm
Forum: Empirical & Molecular Formulas
Topic: 2013 Final - Q1A - Getting the wrong percent of H?
Replies: 2
Views: 414

### Re: 2013 Final - Q1A - Getting the wrong percent of H?

You divide by 2.53 since that's the grams of PCB from the combustion, and you're trying to find the ratio of moles of H to the entire sample, not H2O.
Tue Nov 17, 2015 9:20 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Quiz 3 Prep #6
Replies: 2
Views: 325

### Quiz 3 Prep #6

For the question attached, is the given value the initial concentration or the equilibrium concentration? Do you have to use an ICE box?
Wed Nov 11, 2015 5:17 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordinate Compound Formulas
Replies: 1
Views: 316

### Re: Coordinate Compound Formulas

The order should not matter when writing the formula, but when writing the name, the ligands are written in alphabetical order.
Sun Nov 01, 2015 5:35 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Orders with decimals
Replies: 3
Views: 1783

### Re: Bond Orders with decimals

Usually it shows that it has resonance, but it is not necessary that it will.
Tue Oct 27, 2015 10:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: I3- molecular shape
Replies: 1
Views: 916

### Re: 4.13a

The three lone pairs repel the I equally, which results in a linear shape. Since I3- has 5 regions of electron density, it is first put into the trigonal bipyramidal structure, which shows that the lone pairs are equitorial and the I atoms are axial, showing that the molecule is linear.
Sat Oct 24, 2015 5:45 pm
Forum: Lewis Structures
Topic: hypobromite ion Lewis structure
Replies: 1
Views: 1119

### Re: hypobromite ion Lewis structure

If there were to be a double bond between Br and O, the structure would have 2 lone pairs on Br and 2 on O. This would make the total number of valence electrons 12, while BrO- requires 14.
Sat Oct 24, 2015 5:42 pm
Forum: Lewis Structures
Topic: exceptions to octect
Replies: 1
Views: 358

### Re: exceptions to octect

Boron usually forms compounds with six valence electrons, so it is an exception (as in BF3) but compounds like these are reactive and usually form the compound BF4- instead.
Sat Oct 24, 2015 5:35 pm
Forum: Lewis Structures
Topic: Isolobal Analogy
Replies: 1
Views: 251

### Isolobal Analogy

In 3.101b, the question asks for the structure of benzene, but with N replacing the CH groups. Could this be possible with other elements in Group 15 as well? Also, are there any restrictions involving this concept of replacing certain elements with other similar structures?
Sun Oct 04, 2015 5:45 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Absorption vs. Emission Spectrum
Replies: 1
Views: 466

### Re: Absorption vs. Emission Spectrum

If there is enough light energy, the electrons will be excited, causing them to move to the next level. The light causes the electrons to emit the energy and the absorption and emission spectrums are the same because the amount of energy that goes in has to come out.

Hope this helps!

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