Search found 18 matches

by 504608290
Sun Mar 13, 2016 2:05 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Final 2013 4A Finding Q
Replies: 2
Views: 541

Re: Final 2013 4A Finding Q

Oh ok and it's because over time the reaction is taking the oxygen and forming something else with it, so the overall concentration of oxygen will go down. Which is why in part B you have to find the because that's how the concentration of oxygen has changed over time.
by 504608290
Sat Mar 12, 2016 6:41 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Final 2013 4A Finding Q
Replies: 2
Views: 541

Final 2013 4A Finding Q

On Final 2013 Number 4A, why do you use the nernst equation and not just the standard Q equation? Because the Reaction quotient for that reaction would be
and they give you a concentration for Oxygen so why not just do 1 divided by the concentration of oxygen?
by 504608290
Sat Mar 05, 2016 1:18 pm
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Conformations for the Final
Replies: 1
Views: 296

Conformations for the Final

On Friday, Professor Lavelle said specifically that we do not need to know how to draw conformations, just to name them, but in the past finals, it asks to draw them. Is this year's going to be different in that we will only need to name and not draw them?
by 504608290
Tue Feb 09, 2016 4:15 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 14.37 cell potentials with HCl
Replies: 1
Views: 344

14.37 cell potentials with HCl

When calculating cell potential questions like the ones in 14.37 (for example Pt|H_{2}|HCl||HCl|H_{2}|Pt ) the solutions manual simply ignores the Cl- and only the H+ are counted. Why is that? Is Cl- always ignored when calculating cell potentials involving HCl? I can't find anything mentioning this...
by 504608290
Tue Feb 09, 2016 1:28 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Gibbs Free Energy
Replies: 2
Views: 619

Re: Gibbs Free Energy

How do you know the formation reaction? Is it given somewhere? How do you know that it is and not the other way around.
by 504608290
Tue Jan 26, 2016 4:06 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Reversible vs. Irreversible
Replies: 2
Views: 332

Re: Reversible vs. Irreversible

However when doing problems asking for the change in entropy, the change in entropy appears to be the same, even though reversible is supposed to do more work. In the book there are a couple of diagrams showing that in irreversible systems there is no work done, or no heat transferred, yet the chang...
by 504608290
Tue Jan 26, 2016 2:33 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Reversible vs. Irreversible
Replies: 2
Views: 332

Reversible vs. Irreversible

How exactly do reversible and irreversible systems work? I understand that in reversible systems they are at equilibrium with the surroundings and that they can be reversed by putting more energy into the surroundings and then it reverses the system while in irreversible systems it just releases and...
by 504608290
Mon Jan 25, 2016 6:25 pm
Forum: Phase Changes & Related Calculations
Topic: Exact melting point of water
Replies: 1
Views: 290

Exact melting point of water

Will we be expected to split hairs on the exact melting temperature of water? Meaning do we need to use 273.15K? Or can we just use 273K?
by 504608290
Tue Jan 19, 2016 11:10 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard Enthalpy of Formation=0?
Replies: 2
Views: 456

Re: Standard Enthalpy of Formation=0?

are the most stable form of elements and so elements will naturally always want to go to this form, hence the enthalpy is zero.
by 504608290
Tue Jan 19, 2016 11:08 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Isothermal Reactions
Replies: 4
Views: 577

Re: Isothermal Reactions

Isothermal means that there is no heat exchange and no temperature change. Often this is also an isolated system so there is no exchange of matter as well.
by 504608290
Sat Jan 09, 2016 6:54 pm
Forum: Phase Changes & Related Calculations
Topic: Density as an Intensive Property
Replies: 1
Views: 967

Density as an Intensive Property

How exactly does density work as an intensive property? I know that when you divide heat capacity by either grams present or moles present you get specific heat capacity and molar heat capacity respectively, but how exactly does it work as an intensive property? Is it because the relative ratio allo...
by 504608290
Thu Dec 03, 2015 12:39 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Nominal Concentration
Replies: 1
Views: 6408

Nominal Concentration

For number 12.25, it asks you to calculate the initial molarity of Ba(OH)_{2} and the molarities of Ba^{^{2+}} , OH^{^{-}} , and H_{3}O^{^{+}} in an aqueous solution that contains .43 g of Ba(OH)_{2} in .1L of solution. How do you do this problem? In the solutions manual it mentions ...
by 504608290
Sun Nov 29, 2015 7:36 pm
Forum: Naming
Topic: VIDEO: Naming Coordination Compounds
Replies: 2
Views: 422

Re: VIDEO: Naming Coordination Compounds

Sorry there was an editing error that me and my partner did not catch. it occurs at the end of the first section as we begin explaining the adding of the prefix on the ligands. The subscript of 5 on the \left ( OH_{2} \right )_{5} becomes the prefix of penta on the aqua so it becomes pentaaq...
by 504608290
Sat Nov 28, 2015 1:16 pm
Forum: Naming
Topic: VIDEO: Naming Coordination Compounds
Replies: 2
Views: 422

VIDEO: Naming Coordination Compounds

chem video.wmv [ 420.41 MiB | Viewed 422 times ]

Guide on naming coordination compounds
by 504608290
Mon Oct 26, 2015 11:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Resonance vs Double bonds
Replies: 1
Views: 358

Resonance vs Double bonds

When you're drawing the lewis structures for molecules such as NO_{2}^{-} and SO_{2} would we be marked incorrect on a quiz or midterm if we drew them as O=S=O as opposed to O-S=O with resonance? because the O=S=O is more stable with all formal charges being 0 while the resonance structures have a +...
by 504608290
Sun Oct 25, 2015 4:31 pm
Forum: Electronegativity
Topic: Electronegativity Values
Replies: 1
Views: 429

Electronegativity Values

Will we need to know the electronegativity values of elements on the quiz?
by 504608290
Fri Oct 09, 2015 1:39 pm
Forum: Significant Figures
Topic: Periodic Table Molar Masses
Replies: 1
Views: 480

Periodic Table Molar Masses

Hi everyone, my question is for quiz and exams do we use the exact numbers on the periodic table? For example, for carbon would we use 12 or 12.011? I know in some of the modules Dr. Lavelle just rounded Oxygen to 16 instead of 15.999, but in the solutions manual while doing homework, my answers wou...
by 504608290
Fri Oct 02, 2015 1:37 pm
Forum: Properties of Light
Topic: Relationship between frequency and wavelength
Replies: 7
Views: 1579

Re: Relationship between frequency and wavelength

The equation c=(frequency)(wavelength) gives the formula for frequency and wavelength. Light only has one speed, the speed of light, it doesn't change, it's a constant. Therefore when you change one of the variables you must change the other inversely or else you will end up with a speed of light th...

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