CHEMISTRY COMMUNITY

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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 $\Delta [O_{2}]$ because that's how the concentration of oxygen has changed over time.

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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 $\frac{1}{[O_{2}]}$
and they give you a concentration for Oxygen so why not just do 1 divided by the concentration of oxygen?

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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?

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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...

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How do you know the formation reaction? Is it given somewhere? How do you know that it is $Tl^{3+}+e^{-}\rightarrow Tl$ and not the other way around.

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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...

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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...

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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?

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$O_{2}, N_{2}, H_{2},$ are the most stable form of elements and so elements will naturally always want to go to this form, hence the enthalpy is zero.

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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.

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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...

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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 ...

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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...

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

Guide on naming coordination compounds

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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 +...

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Will we need to know the electronegativity values of elements on the quiz?

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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...

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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...

CHEMISTRY COMMUNITY

Search found 18 matches

Re: Final 2013 4A Finding Q

Final 2013 4A Finding Q

Conformations for the Final

14.37 cell potentials with HCl

Re: Gibbs Free Energy

Re: Reversible vs. Irreversible

Reversible vs. Irreversible

Exact melting point of water

Re: Standard Enthalpy of Formation=0?

Re: Isothermal Reactions

Density as an Intensive Property

Nominal Concentration

Re: VIDEO: Naming Coordination Compounds

VIDEO: Naming Coordination Compounds

Resonance vs Double bonds

Electronegativity Values

Periodic Table Molar Masses

Re: Relationship between frequency and wavelength