CHEMISTRY COMMUNITY

KylieY_3B

I think knowing the name (ethylenediamine) is necessary, but not the formula.

KylieY_3B

I believe writing 90 degrees would be sufficient.

KylieY_3B

When writing out the full name for coordinate compounds which include a ligand such as ethylenediamine (en), can we still use the shorthand or do we have to remember the actual names?

KylieY_3B

The most common ones are good to know, I think doing the homework will make it clear which ones come up the most.

KylieY_3B

Okay thank you!

KylieY_3B

Hi, could someone explain why [Co(CN)5(OH2)]^2- has aqua in front of the rest of its name in the answer key?

KylieY_3B

I believe when typically drawing lewis structures for ionic compounds, you include the ions in brackets to distinguish them from covalent compounds.

KylieY_3B

The formal charge is closer to 0 for the central oxygen atom when it has a lone pair and one double bond and one single bond.

KylieY_3B

I believe it's for the entire molecule.

KylieY_3B

For part b, I've been having difficulty with part b, which is the molecule (CH3)2Be. I understand the basic molecular shape and geometry, but I'm not sure I understand the Lewis structure. From what I've looked up, Be has single bonds with Carbon but no lone pairs. How is this possible if Be doesn't...

KylieY_3B

whitneyh_4_4G wrote:If you click on this link you can download a software that shows molecules in 3D and you can move them around so you have a better idea of the shapes and angles! If that doesn't help you with remembering molecule bond angles for different shapes then I would just memorize them.

Wow! Thank you!

KylieY_3B

TeCl4 has different bond angles because of its molecular geometry. It has seesaw geometry, since it has 4 single bonds and one lone pair. All seesaw geometries will have 90, 120, and 180 degree angles in their 3-D shape. If you look at a picture of "seesaw geometry" you can see each of th...

KylieY_3B

Why do some structures have bond angles of different degrees? For example, in my discussion section we used the example of TeCl4 as having angles of both 120 degrees and 90 degrees. Also, how do we determine when this is the case?

KylieY_3B

Could someone explain how to approach 2.35?

Here is the text: 2.35 (a) Write an expression for the total coulombic potential energy for a lithium atom. (b) What does each individual term represent?

KylieY_3B

I think lone pairs matter when drawing the Lewis structure (since shape is based off of Lewis structure) but nomenclature is based off of number of bonds and angle. So you still have to be aware of the lone pairs, it's just not a necessity for the naming specifically.

KylieY_3B

When drawing a Lewis dot structure, how do we know when to draw a molecule with double bonds or when to draw in lone pairs?

For example, CH2Cl2 has 20 valence electrons, but how do we know whether to draw Carbon and Chlorine with double bonds or to draw in lone pairs for chlorine?

KylieY_3B

Degenerate atomic orbitals are orbitals that have the same energy level.

KylieY_3B

So you would use the Heisenberg indeterminancy equation, which is (uncertainty in momentum) * (uncertainty in position) is greater than h/4pi. Momentum is mass times velocity so you would need to multiply its velocity (which is given) by it's weight (also given). Since the given velocity is in mph y...

KylieY_3B

I think if there's a review session including it, it's fair game for the midterm. But it won't be a calculation question, it would probably be a conceptual question.

KylieY_3B

Thank you! My TA in discussion yesterday also confirmed this, so we know for sure it's true now.

KylieY_3B

This is from homework problem 3.21 c from the 6th edition. The shorthand used for Te 2- is [Xe], which comes after tellurium in the periodic table. When does an ion use the noble gas that comes before in its electron configuration and when does it use the noble gas which comes afterwards? Sorry, I d...

KylieY_3B

Ahh, yes, that's it. Thank you!

KylieY_3B

For question 1.39 in the 6th edition I've been having serious issues getting the correct answer while using De Broglie's Equation. The conversions I've been using is the given 1 ounce = 28.3 grams, 1609 meters = 1 mile and 60 sec = 1 hour. The answer supplied at the back of the textbook lists it as ...

KylieY_3B

Thank you!

For part B (determining how much energy needed to remove electron from metal surface), would I use the equation Ek = .5 (Me)(Ve)^2?

KylieY_3B

Could someone explain how to solve HW problem 33? In particular part A is causing me trouble.

Chemistry Community won't let me copy and paste the text of a question but it essentially asks to find the wavelength of an emitted electron with a velocity of 3600 kilometers per second.

KylieY_3B

I think the maximum would be 1 million electrons, because there is a 1:1 ratio of photons to electrons in terms of energy. Each photon has enough energy to eject one electron and no more.

KylieY_3B

I'm not completely sure how scientists would officially classify it, but I believe that each human sees light slightly differently depending on their biology. The exact wavelength range for each color is an approximate because some people (and languages!) define the threshold between color in differ...

KylieY_3B

Hi, I'm curious about the reasoning for the answer to question 1.3 (6th edition). The question is "Which of the following happens when the frequency of electromagnetic radiation decreases? Explain your reasoning." I understand why most of the scenarios don't happen, except c) "The ext...

KylieY_3B

You divide 1 H2O molecule by Avogadro's constant (6.02 * 10^23) to convert to moles, then multiple by molar mass to convert to grams.

KylieY_3B

I have the 6th edition and it's Fe3Br8 for me. It's probably a typo.

KylieY_3B

Could someone explain how to find the net number of moles of gas produced for number 19 on the second review module? It involves the combustion of 4 moles of butane (C4H10) gas. I understand how to balance the equation but I'm unsure how to determine the net number of moles of gas produced. The poss...

CHEMISTRY COMMUNITY

Search found 31 matches

Re: Do we need to know the ligand (en)?

Re: Bond angles

Shorthands

Re: Memorizing Acid and Bases

Re: 6th Edition 29c

6th Edition 29c

Re: 3.39

Re: 4.17

Re: 4.46

Help w/ 4.19 (6th edition)

Re: Multiple different bond angles

Re: Multiple different bond angles

Multiple different bond angles

Help with 2.35 (6th edition)

Re: Naming the molecular shape

Double bonds vs. lone pairs

Re: Degeneration

Re: Midterm Question #2

Re: Midterm

Re: Can someone explain Te2-?

Can someone explain Te2-?

Re: Can't quite get the answer right

Can't quite get the answer right

Re: Help with 33 (6th edition) [ENDORSED]

Help with 33 (6th edition) [ENDORSED]

Re: Photoelectric Effect

Re: Electromagnetic Spectrum: Colors

Explaining answer for 1.3

Re: 6th Edition E27, First Part

Re: (Typo??) HW L.35 - 7th edition

Need help w/ determining the moles of gas produced