CHEMISTRY COMMUNITY

Joseph_Ghaly_2L

Why do we assume that the expansion and temperature change aren't simultaneous? My intuition is to assume that since volume expands from 3.0 to 3.5 liters, we wouldn't use the equation with constant volume but with constant pressure. Are these types of problems usually this way (where volume expands...

Joseph_Ghaly_2L

For question 1B, aren't you supposed to use Cp instead of Cv? In the answer, Cv is used but volume is not constant while temperature is. The variable in the subscript in these is supposed to be the variable held constant, right?

Joseph_Ghaly_2L

veeksha25 wrote:Do you include the catalyst when writing the rate law?

Yes, because it affects the rate of the reaction.

Joseph_Ghaly_2L

Propyl has only 7 hydrogens while propane has 8 hydrogens. The carbon that is bonded to the parent chain is also bonded to two other carbons, so it can only be bonded to one hydrogen. The other two carbons in the cyclopropyl group have 3 hydrogens each, so in total there are three carbons and seven...

Joseph_Ghaly_2L

I think it is because electric cell potential is essentially equal to the sum of the reduction potential and the oxidation potential. Because the anode is oxidized at the same rate that the cathode is reduced, the sum of the potentials does not change no matter the quantity.

Joseph_Ghaly_2L

The .05916 doesn't just come from plugging in 298K into the Nernst equation. You didn't make a mistake, but the difference is that the variation with .05916 has log with base 10 and the regular Nernst equation has natural log. That's why the numbers are different.

Joseph_Ghaly_2L

Electrons will never go from hydrogen to something else, but electrons can go from something to hydrogen. A bond between hydrogen and another element can break however, and both electrons from the bond can go to the other element. But, these electrons come from the bond, not the hydrogen.

Joseph_Ghaly_2L

Those equations are on the equation sheet, but you will probably have to know which one is for constant pressure or constant temperature. Also, a reversible heat transfer simply implies a change in volume under constant temperature; pressure can decrease or stay the same, but as you can see, the equ...

Joseph_Ghaly_2L

You would use this equation when calculating the heat energy necessary for phase changes (e.g. how much heat energy [q] would you need to completely convert 125g of water at 0 degrees Celsius into steam at 100 degrees celsius). If you remember the diagram for phase changes, the part of the diagram t...

Joseph_Ghaly_2L

There's no formula for how many structural isomers an alkane has, so you'd have to look them up. For alkanes with total # carbons 1-10, these are how many isomers the alkane has according to the internet. # carbons:# isomers

1:1, 2:1, 3:1, 4:2, 5:3, 6:5, 7:9, 8:18, 9:35, 10:75

Joseph_Ghaly_2L

When the standard reduction potential of a half-cell reaction is negative, the electrode in that reaction is going to be oxidized. The rule of thumb is that the more negative the standard reduction potential, the more likely it is to be oxidized, and the more positive the potential, the more likely ...

Joseph_Ghaly_2L

In the quiz 1 preparation in the course reader, what makes the name of the substituent 4-isopropyl as opposed to just 4-propyl?

Joseph_Ghaly_2L

It was mention once or twice I think, there's an example of deprotonation in the course reader on page 156. It's labeled as ionization, but it's the same as deprotonation.

Joseph_Ghaly_2L

Can somebody explain why CH3 has a weaker electron withdrawing ability than H?

Joseph_Ghaly_2L

Can someone explain how the formal charge for Corrin-DMB is calculated in the second part of the problem?

Joseph_Ghaly_2L

Can someone explain how the values for the change in molar concentration in the ICE table on p. 141 of the course reader is calculated?

Joseph_Ghaly_2L

What units do we need to convert to for energy when working with photoelectric effect problems?

Joseph_Ghaly_2L

The only drawings we have done have been Lewis structures. There hasn't been any indication that we would have to draw a 3-D representation of a molecule, so I would definitely not be concerned with that. Just know how to draw Lewis structures and understand what the shape of the molecule is with th...

Joseph_Ghaly_2L

When zinc loses an electron, it'll lose it from its highest energy level at n=4. Zinc's ground state electron configuration is [Ar]3d10 4s2. Zinc with a positive charge of 2 (Zn^2+) would then have a configuration of [Ar] 3d10. Although it has the same number of electrons as nickel, their structures...

Joseph_Ghaly_2L

I think the character of the bond has to be experimentally observed to find a definite answer to whether it's ionic or covalent. Between 1.5 and 2.0 is a gray area, so I doubt we would be expected to know what type of bonds a certain molecule/salt has.

Joseph_Ghaly_2L

A TA recommended we know the wavelengths of visible light but other than that it seems we aren't expected to know the different parts of the spectrum

Joseph_Ghaly_2L

Does the equation only hold true under the assumption that the electrons carry no rotational kinetic energy? Why is only translational kinetic energy included in the equation?

CHEMISTRY COMMUNITY

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Re: Winter 2013 Final 1B

Winter 2013 Final 1B

Re: Catalyst that is used and produced

Re: Naming (from example in course reader)

Re: Cell potential

Re: final exam 2013 q3c

Re: Hydrogen in Reaction Mechanisms

Re: Constant Volume and Constant Pressure

Re: heat question

Re: 1.23 in Introduction to Organic Chemistry Course reader

Re: 2008 Final question 3B

"Iso"

Re: Deprotonation Percentage

2013 Final #7B [ENDORSED]

Practice Final 2015 #5A

Example in Course Reader

Units in Photoelectric Effect

Re: Drawings for Final

Re: Electron Configuration exceptions

Re: determining ionic/covalent from elctronegativity

Re: frequencies [ENDORSED]

Re: Kinetic Energy