CHEMISTRY COMMUNITY

Emma Leshan 1B

I don't understand why SO3 is acidic. I don't see why it would accept protons. Doesn't it already have -2 charge?

Emma Leshan 1B

Ligands are more likely to be polydentate if there are many atoms between the ones with lone pairs. This allows the molecule to bend, interacting with the metal in more than one place. Also, I think one reason CO3 2- can't be tridentate is due to its double bond, which would make it harder for the m...

Emma Leshan 1B

https://quizlet.com/3604768/molecular-g ... ash-cards/

This is also helpful.

Emma Leshan 1B

VSEPR refers to the notation and also the way of finding the molecular shape from the Lewis structure.

Emma Leshan 1B

Remember how the p-orbitals are oriented: one along the x-axis, one along the y-axis, and one along the z-axis. Because of this orientation, only one of the bonds can overlap the orbitals and be a sigma bond. The other orbitals are side-by-side and therefore form pi bonds. <img src="https://d2g...

Emma Leshan 1B

So if there's a double bond, and 2 single bonds on carbon, the hybridization would be sp2? How does that work in respect to valence electrons?

Emma Leshan 1B

You have to look at the electronegativity of each element involved. Technically, every covalent bond has polarity unless it is between 2 of the same elements (O2 for example). However, some bonds are more polar (example: C-H bonds are less polar than O-H bonds) due to the differences in electronegat...

Emma Leshan 1B

Remember that a Lewis Structure is just a 2D model of a 3D shape. So for example, in water, with a tetrahedral shape, every region of electron density is next to every other, so there is no "top" or bottom. With Lewis structures, it doesn't matter where you draw the lone pairs because it d...

Emma Leshan 1B

Both Lewis structures have one double bonded O and the other(s) are single bonded. Because of resonance, the double bonds are shared throughout the molecule. This makes the bond lengths approximately equal in the molecules even though technically SO2 should be a little shorter due to the double bond...

Emma Leshan 1B

The partial negative results from the electrons being pulled toward the more electronegative atom, which is why the arrow points toward the partial negative: that is the way the electrons are being pulled.

Emma Leshan 1B

We discussed the strength of the interactions Alejandro listed as well as what effect interaction strength has on properties of a compound.

Emma Leshan 1B

Remember that O always has an octet because of its high electronegativity, and that should help.

Emma Leshan 1B

Formal charge = number of lone pair electrons - 1/2 * number of bonding electrons

Emma Leshan 1B

Group 15 includes N, P, As, Sb, Bi. Each has a valence electron configuration of (n-1)d10 ns2 np3, the d group is not included because the electrons in the d subshell are in the shell n-1, so they aren't valence electrons. For example, arsenic has a configuration of [Ar] 3d10 4s2 4p3. Because the d ...

Emma Leshan 1B

Also, since chlorine and sodium have fewer electrons, there is less shielding, making the effective nuclear charge larger and making it harder to remove electrons.

Emma Leshan 1B

I was wondering this too, so I looked it up. Apparently, a half-filled p subshell is more stable than one with only 2 electrons, so this is why carbon has a higher electron affinity than nitrogen.

Emma Leshan 1B

Inert gases have a full outer energy shell, so using them is basically saying that the last energy shell is completely full, and then you add the rest of the configuration for whichever atom you are specifying. For example, if I was talking about carbon, I would say [He] 2s^2 2p^2 to say that n=1 is...

Emma Leshan 1B

I don't think you necessarily need to calculate whether the spin is up or down, you just need to know that if there are 2 electrons occupying the same orbital, one will spin up and one down.

Emma Leshan 1B

The Uncertainty Equation stated in the textbook has 1/2 * h-bar, and since h-bar is h/2pi, we use h/4pi.

Emma Leshan 1B

If we find it faster and easier to use the Rydberg equation on a test or quiz, are we allowed to use it as long as we understand the concepts?

Emma Leshan 1B

So as a follow up, when using the Rydberg equation, the negative is there for the same reason? Is it because the Rydberg equation is derived from this equation? When calculating frequency from the Rydberg equation, we could just ignore the negative, correct?

Emma Leshan 1B

Continuing off that note, when light acts as a wave, or for any wave, the intensity relates to the amplitude/height of the wave.

Emma Leshan 1B

I believe it's preferred for very small wavelengths such as ones in the visible region to be written in nanometers, but you won't get points off for writing it in meters.

Emma Leshan 1B

The first wavelength (656.3) is the longest, meaning it has the lowest energy. This must mean it must result from the smallest energy level transition. Since the Balmer series is for visible light, it involves n=2. In this case, the fist stated wavelength is for the transition n1=2 to n2=3, the smal...

Emma Leshan 1B

Use whichever constant is given on the test just to be safe.

Emma Leshan 1B

Also, Dr Lavelle said all the equations would be on the test, but you should know how to use them. I'm sure he doesn't expect us to memorize the EM spectrum, as he gives all constants on the tests. Hope this helps!

Emma Leshan 1B

25. Photoelectric experiments gave rise to a new equation relating the energy of light to its frequency. Select the right equation. A. λv = c B. Ek = mv2/2 C. mv2/2 = hv - φ D. E = hv E. None of the above I thought the answer would be c, but it said this was wrong. Can someone please explain?

Emma Leshan 1B

I also find it very helpful to use unit conversions aka dimensional analysis to solve problems like this. For example, you know 0.12*750mL will give you the volume in mL. Now you want to find the mass in grams, so you need the units to be g/mL in order for mL to cancel, and you'll be left with grams...

Emma Leshan 1B

Dr Lavelle said after class that we wouldn't be expected to know this for the first test.

Emma Leshan 1B

Definitely multiply the whole thing by 2. Dr Lavelle said in class that stoichiometric coefficients should be whole numbers.

CHEMISTRY COMMUNITY

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Re: HW 12.17 [ENDORSED]

Re: HW 17.33

Re: List of the different shapes

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Re: 3.85 part b

Re: Dipole moment as a vector [ENDORSED]

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Re: The Negative Sign in En = -hR/n^2

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Post module quiz #25

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