Search found 26 matches

by KaylaH
Thu Mar 10, 2016 2:17 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Final 2014 Question 4 (Pikachu Galvanic Cell)
Replies: 1
Views: 250

Final 2014 Question 4 (Pikachu Galvanic Cell)

Im confused on part A. For this question, how do we know which chemicals to choose? From what I remember, in order to get the highest possible voltage you would choose too reactions that have the biggest charge difference of Ecell in order to get the largest positive value of Ecell. I'm just not sur...
by KaylaH
Wed Mar 09, 2016 9:28 pm
Forum: *Cycloalkenes
Topic: Final 2012 Question 5
Replies: 2
Views: 581

Final 2012 Question 5

Why is molecule B a cis molecule?
by KaylaH
Wed Mar 09, 2016 4:40 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Winter Final 2012 2C
Replies: 1
Views: 351

Winter Final 2012 2C

In part c of question 2 dealing with He heated up to 100 degrees, can someone please explain why Cv is used for the ideal gas and not Cp?
by KaylaH
Tue Mar 08, 2016 6:16 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: pH and cell potential
Replies: 5
Views: 7186

Re: pH and cell potential

Why would the pOH decreasing cause the OH- concentration to increase? Wouldnt it decrease according to the equation pOH=-log[OH-]? Because if pH is increased from 11 to 13 (just for example), that means that pOH would decrease to 1. This means [OH-]=10^-1. If you plug this new value in for the conc...
by KaylaH
Fri Feb 26, 2016 7:51 pm
Forum: *Electrophiles
Topic: Psuedo-Equiliroum Constant
Replies: 1
Views: 313

Psuedo-Equiliroum Constant

Can someone please explain the signigficance of the Psuedo-Equiliroum Constant? In regards to the parameters for the psuedo-thermodynamics, what the reason behind why delta G a large positive value?
by KaylaH
Fri Feb 26, 2016 7:44 pm
Forum: *Ethers
Topic: Numbering carbons in the chain for ethers
Replies: 1
Views: 371

Re: Numbering carbons in the chain for ethers

Technically yes because the functional group dictates the carbon numbering, so the carbon next to the oxygen for the ether group would be the #1 carbon.
by KaylaH
Fri Feb 26, 2016 7:42 pm
Forum: General Science Questions
Topic: Constitutional isomers
Replies: 1
Views: 659

Re: Constitutional isomers

I don't think there is a specific "rule" or "guide". To determine constitutional isomers, you just have to look at your structure that you drew and see how many different, unique structures you are able to come up with (making sure you just didn't flip the structure because in or...
by KaylaH
Sun Feb 07, 2016 6:00 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Midterm Winter 2012 #1A and B
Replies: 1
Views: 316

Midterm Winter 2012 #1A and B

Why is the equation -q(ceramic)=+q(water)? I understand the qsys=-qsurr equation, so why is it the way that they wrote it with the ceramic being negative? Isn't the ceramic brick the system? Also, in question #1B it has the same thing where qrxn is negative and qcalorimeter is positive (-qrxn=+qcalo...
by KaylaH
Sun Feb 07, 2016 1:01 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Midterm Winter 2011 #1
Replies: 1
Views: 397

Midterm Winter 2011 #1

I don't understand how they got the equation to solve this question. Shouldn't the correct equation to solve for Ccal be
. So, why did they write it differently? Also, for the units, shouldn't it be kJ/degrees C...not kJ.C?
by KaylaH
Sat Feb 06, 2016 4:06 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Need help on galvanic cells
Replies: 1
Views: 229

Need help on galvanic cells

How do you tell how which substances are the products and the reactants for galvanic cells? For example, in question 14.9 (b) they give you C(gr)|H2(g)|H+(aq)||Cl-(aq)|Cl2(g)|Pt(s)...and for the anode reaction it is 2H+(aq) +2e---->H2(g) but for the cathode it is Cl2(g)+2e---->2Cl- How do you know t...
by KaylaH
Sun Jan 31, 2016 6:23 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt bridges/porous discs
Replies: 1
Views: 268

Re: Salt bridges/porous discs

Because it is specific to only allowing SO4 back and forth, from high concentration on the cathode to low concentration on the anode side. It doesn't allow any other substance other than the anion SO4 cross over and it is used to balance the charge.
by KaylaH
Tue Jan 26, 2016 1:15 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Heating Curve
Replies: 1
Views: 328

Heating Curve

How is the heating curve affected when the enthalpy of vaporization is less than that of the enthalpy of fusion? For example, when asked to draw a heating curve for a substance not specified, and H fusion= 60 kJ/mol and H vap=10 kJ/mol, what would the heating curve look like?
by KaylaH
Fri Jan 22, 2016 7:44 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Relationship Between Degeneracy and Entropy
Replies: 1
Views: 258

Relationship Between Degeneracy and Entropy

I get the individual definitions of Degeneracy and Entropy, but what is the significance of their relationship with one another?
by KaylaH
Mon Jan 18, 2016 2:26 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Entropy and Degeneracy
Replies: 1
Views: 436

Re: Entropy and Degeneracy

Entropy is the measure how much the energy of atoms and molecules become continuously more spread out in a process and can be defined in terms of thermodynamic quantities. This relates to degeneracy because low entropy means little disorder and high entropy means great disorder. Entropy is also a st...
by KaylaH
Sun Jan 10, 2016 2:22 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: enthalpy
Replies: 2
Views: 393

Re: enthalpy

I might be mistaken but it sounds like you're using enthalpy and energy interchangeably. Remember, the enthalpy is not a measure of the energy that a system has in the same sense as the internal energy. Also, from the text it seems that when energy is transferred to a constant-pressure system as hea...
by KaylaH
Tue Dec 01, 2015 2:57 pm
Forum: Amphoteric Compounds
Topic: Oxides: Basic, acidic, or amphoteric
Replies: 1
Views: 476

Oxides: Basic, acidic, or amphoteric

What is a simple way to tell if an oxide is acidic basic or amphoteric? I'm mostly confused on the amphoteric aspect...
by KaylaH
Sun Nov 29, 2015 7:10 pm
Forum: Identifying Acidic & Basic Salts
Topic: Determine if salt is acidic, basic, or neutral
Replies: 4
Views: 2867

Re: Determine if salt is acidic, basic, or neutral

A salt formed between a weak acid and a weak base can be acidic, basic, or neutral depending on the relative strengths of the acid and base. If Ka(cation) > Kb(anion) the solution of the salt is acidic. If Ka(cation) = Kb(anion) the solution of the salt is neutral.
by KaylaH
Wed Nov 18, 2015 11:53 am
Forum: Naming
Topic: Oxidation Number in Naming
Replies: 1
Views: 333

Re: Oxidation Number in Naming

I'm a little confused by your question. Are you asking why is the oxidation state in the second example is not "as obvious" as the first? If so, I guess my response to that is that you have to take into consideration the charges of the ligands in order to find the oxidation state of the TM...
by KaylaH
Sun Nov 15, 2015 2:34 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Sig Figs for Equilibrium Constants
Replies: 1
Views: 288

Re: Sig Figs for Equilibrium Constants

It may have just been a mistake in the answer key because when multiplying the lowest number of sig figs is kept. If two sig figs was the lowest then the value of K should have been in two sig figs.
by KaylaH
Thu Nov 05, 2015 3:19 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Order
Replies: 5
Views: 1819

Re: Bond Order

If Bond order is not a full number, then it does mean resonance structures (combination of single and double, or double and triple) are at play because the electrons are delocalized.
by KaylaH
Thu Oct 29, 2015 11:12 am
Forum: Ionic & Covalent Bonds
Topic: Double and triple bonds
Replies: 2
Views: 2493

Re: Double and triple bonds

It's not true that only carbon and nitrogen can form double or triple bonds. It really depends on the molecule and finding the most stable lewis structure for that molecule at hand. You have to take formal charge into consideration in order to find the most stable structure.
by KaylaH
Wed Oct 21, 2015 11:36 pm
Forum: Dipole Moments
Topic: Dipole Moments Question
Replies: 1
Views: 473

Re: Dipole Moments Question

A dipole moment is equal to the magnitude of charge times the distance. If for example you took the molecule HCl, we know that they are connected by a single bond (with 3 lone pairs of electrons around Cl). Cl is more electronegative so it will pull the electrons toward it. We would draw an arrow to...
by KaylaH
Thu Oct 15, 2015 1:24 pm
Forum: Trends in The Periodic Table
Topic: Atomic, covalent, ionic radii
Replies: 1
Views: 430

Re: Atomic, covalent, ionic radii

So if we first define an atomic radius as half the distance between the center of neighboring atoms, then a the definition of a covalent radius is the same except that the two atoms are joined by a covalent bond. The same goes for an ionic radius, except it applies to two ions joined by an ionic bon...
by KaylaH
Thu Oct 08, 2015 11:11 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration Sequence
Replies: 1
Views: 387

Re: Electron Configuration Sequence

Vandium is usually written as [Ar] 4s2 3d3, and the 4s2 is written before the 3d3 because it is actually in a lower energy state than the 3d3.
by KaylaH
Fri Oct 02, 2015 12:59 pm
Forum: Properties of Light
Topic: Relationship between frequency and wavelength
Replies: 7
Views: 1389

Re: Relationship between frequency and wavelength

When there is a higher frequency of waves passing by, the wave lengths decrease. When there is a lower frequency of waves passing by, the wavelengths increase...thus showing an inverse relationship between wavelengths and frequency.

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