Search found 30 matches
- Mon Jun 04, 2018 7:11 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: polar and nonpolar molecules
- Replies: 5
- Views: 687
Re: polar and nonpolar molecules
would you just have to know which bonds/molecules would produce a charge or is there a way to tell by looking at the structure?
- Mon Jun 04, 2018 6:36 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligands
- Replies: 3
- Views: 429
Re: Ligands
A ligand is basically the atom that binds to the central atom in a coordinate compound.
- Mon Jun 04, 2018 6:34 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: pi and sigma bonds
- Replies: 3
- Views: 610
Re: pi and sigma bonds
I'm not quite sure of what you are asking for, but I'll write down my notes from what Professor Lavelle said in class. The bonds basically hold the atoms in a coordinate compound together. Sigma bonds: 2 orbitals, each with 1 electron; interact end-to-end to form 1 sigma-bond; allow bound atoms to r...
- Fri Jun 01, 2018 11:03 pm
- Forum: Lewis Structures
- Topic: d-block Lewis structures
- Replies: 3
- Views: 531
d-block Lewis structures
Can someone explain how to draw a Lewis structure of an element from the d-block?
- Fri Jun 01, 2018 11:01 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3458313
Re: Post All Chemistry Jokes Here
I have many chemistry jokes, but I'm afraid they won't get a good reaction.
- Fri Jun 01, 2018 10:53 pm
- Forum: Naming
- Topic: Coordination compound
- Replies: 6
- Views: 908
Re: Coordination compound
A coordination compound basically consists of a central atom with ligands attached to it by covalent bonds
- Wed May 23, 2018 10:18 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Prioritizing Formal Charge
- Replies: 2
- Views: 452
Re: Prioritizing Formal Charge
I'm not sure if this is correct, but I remember that it is best if the center atom has a formal charge of zero but generally, the idea is to get all elements to be as close to 0 as possible.
- Wed May 23, 2018 10:16 am
- Forum: Octet Exceptions
- Topic: Maximum number of electrons in expanded octet
- Replies: 1
- Views: 403
Re: Maximum number of electrons in expanded octet
The most electrons you can add to an expanded octet is 10 because ultimately, you're filling up the d orbital and that can only hold up to 10.
- Wed May 23, 2018 10:15 am
- Forum: Bond Lengths & Energies
- Topic: bond length and charge
- Replies: 3
- Views: 2450
bond length and charge
How does charge influence bond length? Does bond length increase as charge increases as well?
- Fri May 18, 2018 1:11 pm
- Forum: Lewis Structures
- Topic: Test #3
- Replies: 11
- Views: 1357
Re: Test #3
Also, I remember Chem_Mod's answer in another topic, saying that Test 3 will not cover electron configuration since we were already tested about that on the midterm.
- Fri May 18, 2018 1:07 pm
- Forum: Lewis Structures
- Topic: Exceptions to the Octet
- Replies: 5
- Views: 612
Re: Exceptions to the Octet
I remember my TA saying that you can add up to 10 extra electrons since it is the d block that is involved in the expanded octet and it can hold ten electrons.
- Fri May 18, 2018 1:03 pm
- Forum: Lewis Structures
- Topic: 3.41c
- Replies: 2
- Views: 360
3.41c
For more complicated compounds such as the H2C(NH2)COOH given in part c of 3.41, how would you go about figuring out specifically which elements are bound to which ones and in which order? It seems like a rather arduous process to test out possible combinations until you get one that gives the right...
- Sun May 13, 2018 11:11 pm
- Forum: Lewis Structures
- Topic: resonance
- Replies: 6
- Views: 688
Re: resonance
Thanks so much: the replies really cleared it up! A follow-up question: if the correct lewis structure is a combination of the possible "correct" ones, why would we still need to calculate formal charge? Is that just to determine the result of resonance?
- Sun May 13, 2018 10:58 pm
- Forum: Lewis Structures
- Topic: resonance
- Replies: 6
- Views: 688
resonance
Can someone explain the concept of resonance? I still don't really understand what it is exactly and how it relates to drawing Lewis structures.
- Sun May 13, 2018 10:56 pm
- Forum: Lewis Structures
- Topic: Expanded Octet
- Replies: 2
- Views: 319
Re: Expanded Octet
Regarding the expanded octet, it's just that elements that are below the 3rd row have a d orbital or more that can bond if needed
- Sun May 06, 2018 9:19 pm
- Forum: Empirical & Molecular Formulas
- Topic: Test 1/ Question 8 [ENDORSED]
- Replies: 6
- Views: 1012
Re: Test 1/ Question 8 [ENDORSED]
For this, you wouldn't need the mass of the molecule. The structures themselves give you the molecular formula since it shows you exactly how many of each element is in the molecule. You can literally count the how many of each element there are and that is basically the molecular formula. To get th...
- Sun May 06, 2018 9:15 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent vs. Ionic
- Replies: 3
- Views: 499
Re: Covalent vs. Ionic
First off, covalent bonds are between nonmetals and ionic bonds are between a metal and nonmetal. The biggest, and most important, difference is that elements in an ionic bond are more aggressive so it kind of takes the electron, which produces a charge for the overall molecule. Covalent bond elemen...
- Sun May 06, 2018 6:35 pm
- Forum: Ionic & Covalent Bonds
- Topic: Midterm Topics [ENDORSED]
- Replies: 33
- Views: 4861
Re: Midterm Topics [ENDORSED]
Also, does anyone know where we can get practice midterms? Does the test bank have any?
- Mon Apr 30, 2018 3:57 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Using the uncertainty principle [ENDORSED]
- Replies: 2
- Views: 417
Re: Using the uncertainty principle [ENDORSED]
Then, you would plug in 6.626 x 10^-34 for the h in h/2pi
- Mon Apr 30, 2018 3:50 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: cation or anion?
- Replies: 4
- Views: 575
cation or anion?
How do you know if an element will be a cation or anion if it is the same distance away from 2 different noble gases? Will they provide you with the information?
- Mon Apr 30, 2018 3:44 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 3d and 4s orbitals
- Replies: 3
- Views: 405
3d and 4s orbitals
Can someone explain in simple terms why 4s orbitals are a lower energy than 3d and thus should be written first?
- Sun Apr 22, 2018 6:24 pm
- Forum: Photoelectric Effect
- Topic: Threshold Energy [ENDORSED]
- Replies: 4
- Views: 509
Re: Threshold Energy [ENDORSED]
Work function and threshold energy are the same thing.
- Sun Apr 22, 2018 6:17 pm
- Forum: Properties of Light
- Topic: Wavelengths
- Replies: 8
- Views: 668
Re: Wavelengths
My TA said that just as you know the general ranges and order of the wavelengths you should be fine. She did say that it would be best if you knew that visible light is 400 to 700 nm.
- Sun Apr 22, 2018 6:11 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test Number 1
- Replies: 10
- Views: 1218
Re: Test Number 1
The average for my section was around a 22/40. My friend told me that her TA said that they would try to make it so that most people at least passed but I don't know how exactly that's gonna happen. They did say that they were aware of how hard it was and that for test number 2, they would include a...
- Sun Apr 15, 2018 9:11 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3458313
Re: Post All Chemistry Jokes Here
I don't trust atoms...
I heard they make up everything.
I heard they make up everything.
- Sun Apr 15, 2018 9:08 pm
- Forum: SI Units, Unit Conversions
- Topic: Units for Answer
- Replies: 10
- Views: 1180
Re: Units for Answer
You could also see what units the original problem gives for the numbers and follow that.
- Sun Apr 15, 2018 9:04 pm
- Forum: Ideal Gases
- Topic: Reading the textbook
- Replies: 262
- Views: 148181
Re: Reading the textbook
I think reading the textbook definitely helps. Personally, I feel like it gives me a better overview of the big topics I am supposed to be learning. Professor Lavelle's lecture tend to be a little more focused on one specific topic and one specific example so I read the textbook to link ideas togeth...
- Sun Apr 08, 2018 9:42 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3458313
Re: Post All Chemistry Jokes Here
Q: what kind of dogs do scientists have?
A: laboratory retrievers
A: laboratory retrievers
- Sun Apr 08, 2018 9:39 pm
- Forum: Ionic & Covalent Bonds
- Topic: Types of Bonds
- Replies: 10
- Views: 1249
Re: Types of Bonds
Yes, you are exactly right! The only difference is that an ionic bond is a bond between a metal and a nonmetal and then a metallic bond is between 2 metals. Again, just look at the periodic table to determine whether an element is a nonmetal or metal.
- Sun Apr 08, 2018 9:35 pm
- Forum: Ionic & Covalent Bonds
- Topic: Types of Bonds
- Replies: 10
- Views: 1249
Re: Types of Bonds
To put it simply, a covalent bond is a bond between 2 nonmetals. You can just look up the elements on the periodic table to determine if it is a nonmetal. They are to the right of the "staircase"-like divider.