CHEMISTRY COMMUNITY

Betty Wolkeba section 1L

I think the main part we should know is that Lewis acids and bases are involved with electron lone pairs( whether you gain it for an acid or loose it for a base) whereas Bronsted acid and bases have to do with protons (which include H+ atoms) and whether you gain them for a base or donate them for a...

Betty Wolkeba section 1L

Hi, I found a good link that might help
https://www.youtube.com/watch?v=YcSPPKESpwc

But i like to think of it as a sigma bond is a single bond, whereas a pi bond is the second or third bond of the ligand. This video goes more in depth about it. Hope that helps!

Betty Wolkeba section 1L

Sig figs will be taken into consideration on the final as it was on the midterm

Betty Wolkeba section 1L

Will we be expected on the final to know how to make the valence shell electron configurations? The ones with sigma bonds and such

Betty Wolkeba section 1L

How do we calculate the bond order ? And if possible can someone give an example?

Betty Wolkeba section 1L

The larger the size, the more polarizability it has because larger atoms are usually easier to remove electrons from. However, the larger the size, the less polarizing power it has I believe.

Betty Wolkeba section 1L

Two elements being isoelectronic just mean that they have the same number of electrons and the same electron configurations. They can still have different characteristics. For example, K+ and Cl- are isoelectronic with Argon, however, Cl- is larger than K+ because K+ has more protons so it'll pull i...

Betty Wolkeba section 1L

I like to look at the electronegativities of the atoms in the molecule to help. For example, with HCL, Cl is more negative than H so the covalent bond makes electrons to be pulled closer to the CL, making it more partial negative, and H as a result, a partial positive.

Betty Wolkeba section 1L

Will this be a topic addressed on the final?

Betty Wolkeba section 1L

Will we be given the electronegativity of elements of compounds to calculate their electronegative difference or will we be expected to estimate/memorize them?

Betty Wolkeba section 1L

I was doing a practice problem and it was asking which compound is more ionic, LiH or HCl, and I thought the correct answer would be HCl since H and Cl have a greater electronegative distance on the periodic table from each other than Li and H, however, according to the answer key, the correct answe...

Betty Wolkeba section 1L

I believe because Xe is one of the exceptions to the rule that it must have an octet( any element that is after the second period / has an atomic number > 10), it can have as many bonds/electrons as it needs to satisfy the number of electrons in the compound. Both O and F have an atomic number less ...

Betty Wolkeba section 1L

You did 3.56 by accident I think. The BRO and BF4- are from the next problem

Betty Wolkeba section 1L

Can someone explain why Chlorine in this Lewis structure is allowed to break the octet rule and have more? Are there any other elements like Chlorine that might have this exception as well?

Betty Wolkeba section 1L

I like to think of it as the number of valence electrons minus the sum of how many electrons there are around it on the lewis sturcture (a bond=1 electron, a lone pair of electrons =2). The charge would be more negative if there are more electrons required to fill the octet than the number of valenc...

Betty Wolkeba section 1L

The net overall charge is 0. The -1 from the C, and the +1 from the O cancel out to give you the overall net charge of the entire compound (-1+1=0). Hope that helps!

Betty Wolkeba section 1L

After todays's lecture where we learned that the element B doesnt need a full octet, does this rule apply to all the group 13 elements or just some specific ones, and if so, what are they?

Betty Wolkeba section 1L

I dont think we've covered this yet so we dont have to worry about it now

Betty Wolkeba section 1L

I attached an image of it, hope this helps!

Betty Wolkeba section 1L

Can someone explain how to calculate formal charges again? Or if there's another way aside from the equation we learned in class? And if we're trying to ionic element's lewis structure, do we had the charge to the number of electrons to the element/compound?

Betty Wolkeba section 1L

Can someone explain why specifically Chromium and Copper are exceptions? I know what their electron configurations are, but I was wondering why those two elements had different configurations?

Betty Wolkeba section 1L

How would we know when to use the lamda=H*c/E or when to solve for the energy first?

Betty Wolkeba section 1L

Its everything up from chapter 1.1-1.5. None of the material covered on Friday's class will be on Test 2

Betty Wolkeba section 1L

I remember in class he said we should have a basic knowledge of the the spectrum and the ranges. I dont think we'll have to go into too much depth such as knowing the different colors that coordinate to the ranges, but at least know what the ranges are for gamma rays, microwaves, uv rays, etc.

Betty Wolkeba section 1L

Why is it when we solve for the E in the Rydberg equation, we have to switch the sign from a negative to a positive when solving for another variable such as wavelength?

Betty Wolkeba section 1L

Can someone clarify what Professor Lavelle was talking about in lecture about the wavelength and frequency relationships. For example, why is it when the frequency doubles, the wavelength halves? I'm still a little confused on this concept.

Betty Wolkeba section 1L

Plank's constant is the amount of energy a photon carries with the frequency of its electromagnetic wave. We use it whenever we solve for the energy per photon (E= frequency x plank's constant)

Betty Wolkeba section 1L

First I would solve for the number of moles produced for each product but break it down to C,H,O. Then divide each of the moles you got by the lowest number of moles produced. Then you would use those values for the empirical. To find the molecular formula, just divide the given molecular mass by th...

Betty Wolkeba section 1L

Whenever one of the stoichiometric coefficients is a fraction, multiply the entire equation by the denominator. That would get rid of the fraction and multiply all the coefficients by a factor of the denominator.

Betty Wolkeba section 1L

What do you mean by molecular compound? Are you talking about when they give us the name and not the compound? Because if thats the case, we havent learned how to form molecular compounds from names yet

Betty Wolkeba section 1L

Dr. Lavelle did say that he was going to provide us with the chemical formulas for now, however it probably wouldnt hurt brushing up on how to write chemical formulas for future references.

Betty Wolkeba section 1L

I believe that it would still be the same because essentially, the limiting reactant determines the maximum amount of how much a product would be produced. However, someone should reassert this.

CHEMISTRY COMMUNITY

Search found 32 matches

Re: H+ Acidic and OH- Basic

Re: pi bonds and sigma bonds [ENDORSED]

Re: Sig Figs for Final

Valence Electron Configurations [ENDORSED]

Finding Bond order

Re: How does size affect polarizing power/ polarizability

Re: Isoelectronic elements and their characteristics

Re: determining dipole moment

MO Theory

Electronegativity Caluclations

Which is more Ionic

Re: Lewis Structure of XeO2F2

Re: 3.55

Exception to Lewis Structure?

Re: formal charge

Re: HW 3.49.C

BF3

Re: "1.20A or 1.40A"

Re: Resonance structure of benzene

Calculating formal charges

Exceptions for Electron Configuartions

Re: In class problem 5/4

Re: Test 2 Material

Re: Memorizing spectrum

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

Wavelength and frequency proportions [ENDORSED]

Re: When to use Planck's Constant [ENDORSED]

Re: Finding Molecular X

Re: Balancing Chemical Reactions

Re: Finding Molecular X

Re: Chemical Formulas [ENDORSED]

Re: In-Class Limiting Reactant and Theoretical Yield Problem [ENDORSED]