Search found 35 matches
- Tue Jun 05, 2018 4:32 pm
- Forum: Naming
- Topic: 17.31 [ENDORSED]
- Replies: 1
- Views: 355
17.31 [ENDORSED]
In this problem, it asks to write the formula given the names in table 17.4. My question is regarding the use of "diaqua". In the table it says it is OH 2 , however in part c of the problem it writes it as (H 2 O) for tetraaminediaquacobalt (III) bromide. While in part d it goes back to us...
- Tue Jun 05, 2018 3:51 pm
- Forum: Bronsted Acids & Bases
- Topic: How to identify a Bronsted acid or base
- Replies: 11
- Views: 4439
Re: How to identify a Bronsted acid or base
I would imagine from our lecture notes, that Bronsted refers to protons either being donated (acid) or accepted (base). While lewis refers to electrons.
- Tue Jun 05, 2018 3:47 pm
- Forum: Hybridization
- Topic: Regions of e- density: Tetrahedral vs. trigonal pyramidal
- Replies: 3
- Views: 472
Regions of e- density: Tetrahedral vs. trigonal pyramidal
If there are 4 regions of electron density, sp3, how would we know if it is tetrahedral shape or trigonal pyramidal? Or would we just have to draw the lewis structure to figure this out?
- Tue Jun 05, 2018 3:38 pm
- Forum: Naming
- Topic: Coordination Compound confusion [ENDORSED]
- Replies: 4
- Views: 722
Re: Coordination Compound confusion [ENDORSED]
How are we supposed to know the names of the compounds? Do we just memorize them or is naming not going to be on the final?
- Tue May 29, 2018 4:39 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Any Other Shapes?
- Replies: 7
- Views: 908
Re: Any Other Shapes?
Are the shapes in the front of chapter 4 the only shapes known in total? Or are they only few of the many shapes possible?
- Tue May 29, 2018 4:37 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Form vs. Shape
- Replies: 2
- Views: 333
Form vs. Shape
Whats the difference between a molecule's form and shape? I saw the post about water being bent and having a tetrahedral form. What is meant by form?
- Tue May 29, 2018 4:32 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: single electron and shape
- Replies: 3
- Views: 351
Re: single electron and shape
I would imagine that a single electron would just make the molecule unstable/reactive. I don't think it would drastically change the shape unless it was stated in class, but then I also googled it and it's giving me complicated answers.
- Tue May 22, 2018 10:06 pm
- Forum: Dipole Moments
- Topic: Topics on Test 3
- Replies: 2
- Views: 400
Re: Topics on Test 3
Based on the website, it says that test 3 covers chapter 3 material. So I don't think the portion of chapter 6 will be on it unless stated otherwise.
- Tue May 22, 2018 9:12 pm
- Forum: Bond Lengths & Energies
- Topic: 3.85 part b
- Replies: 3
- Views: 557
Re: 3.85 part b
or would this just be known by looking up these values in the back of the book/online? or can it be calculated?
- Tue May 22, 2018 9:11 pm
- Forum: Bond Lengths & Energies
- Topic: 3.85 part b
- Replies: 3
- Views: 557
3.85 part b
In this problem it asks to arrange the following molecules/ions in order of decreasing lengths: SO 2 , SO 3 , and SO 3 2- . The answer is SO 3 2- > SO 2 ~SO 3 . I understand why SO 3 2- has the longest length, however I don't understand why the other two would have equal/same lengths? If this were t...
- Sun May 20, 2018 7:05 pm
- Forum: Lewis Structures
- Topic: 3.49 part c
- Replies: 2
- Views: 287
Re: 3.49 part c
Oh I understand now. Thank you!
- Sun May 20, 2018 2:53 pm
- Forum: Lewis Structures
- Topic: 3.49 part c
- Replies: 2
- Views: 287
3.49 part c
In this problem, it asks for the lewis structure and formal charge for CO. The correct answer has a triple bond between C and O (with a +1 charge on C and -1 charge on O), however I calculated the formal charge with double bond between the two and I also got 0 for both elements. Why is it incorrect ...
- Sat May 19, 2018 9:35 pm
- Forum: Resonance Structures
- Topic: Sulfate Lewis Structure
- Replies: 2
- Views: 386
Sulfate Lewis Structure
I have a question about the sulfate lewis structure that was in the 5/11/18 notes. The TA's did an example with sulfate and I was wondering if there are other resonance structures associated with it. For example, in sulfate they wrote that there are 2 single bonds and 2 double bonds. The 2 double bo...
- Sun May 13, 2018 12:01 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal charge of ClO2- [ENDORSED]
- Replies: 4
- Views: 3215
Re: Formal charge of ClO2- [ENDORSED]
Also, just remember that the least electronegative element is the central one. In this case, Cl is less electronegative than oxygen.
- Sat May 12, 2018 6:01 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Calculating formal charges
- Replies: 5
- Views: 1123
Re: Calculating formal charges
Theres another equation (which gives essentially the same answer) just in a different format:
FCelement=(# of valence e-)-(# of lone pair e- + 0.5(#bonding e-))
FCelement=(# of valence e-)-(# of lone pair e- + 0.5(#bonding e-))
- Sat May 12, 2018 5:57 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Oxidation Number & Bonds
- Replies: 6
- Views: 2594
Oxidation Number & Bonds
Hi, I was looking at other posts (from last year) about oxidation numbers (for example 3.23 in the book) and they said for Cl, the oxidation number could be +7 or -1 in order to reach an octet in bonds. When elements bond together, does the oxidation number used just depend on which elements are inv...
- Sat May 05, 2018 11:57 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: homework 2.43 part e [ENDORSED]
- Replies: 8
- Views: 1008
Re: homework 2.43 part e [ENDORSED]
Vivian Gonzalez 1A wrote:I see. So the f block lies in between the 6s-7s and 5d/6d rows?
Yes it does. If you look at the periodic table there should be 2 boxes labelled "57-71 lanthanoids" and "89-103 actinoids", where that section leads to the portion below as an extension.
- Sat May 05, 2018 11:54 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations Exceptions
- Replies: 3
- Views: 406
Re: Electron Configurations Exceptions
I think in class, Professor Lavelle mentioned that we would only be focusing on the first row of the d-block. So it would just be the Copper and Chromium exceptions.
- Tue May 01, 2018 3:52 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 2.17
- Replies: 4
- Views: 508
Re: 2.17
okay thanks for the help!
- Tue May 01, 2018 3:06 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 2.17
- Replies: 4
- Views: 508
Re: 2.17
okay, its starting to make sense now. However is the pattern always going to be l, l-1, -l? So it goes in both positive and negative directions?
- Tue May 01, 2018 1:19 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 2.17
- Replies: 4
- Views: 508
2.17
In this problem we are given the l value, so then I solved for what n (energy level) is (l= n-1), but then I'm confused as to how the answers are
a) 1 orbital
b) 5 orbitals
c) 3 orbitals
d) 7 orbitals
does the value of n just relate to the different shapes?
a) 1 orbital
b) 5 orbitals
c) 3 orbitals
d) 7 orbitals
does the value of n just relate to the different shapes?
- Wed Apr 25, 2018 9:01 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation
- Replies: 4
- Views: 549
Re: Rydberg Equation
Is the Rydberg equation always initial minus final? In my discussion we wrote it as final minus initial? Im a bit confused about which orientation is correct.
- Wed Apr 25, 2018 12:08 am
- Forum: Photoelectric Effect
- Topic: Frequency on Photoelectric Effect
- Replies: 5
- Views: 656
Re: Frequency on Photoelectric Effect
From lecture, I remember Professor Lavelle explaining the experiment where increasing the intensity of the light wouldn't eject any electrons. There is the need to increase the energy, and by increasing the energy is an increase in frequency. Waves with higher frequency have higher energy levels . S...
- Sat Apr 21, 2018 4:25 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Finding velocity (delta)V [ENDORSED]
- Replies: 2
- Views: 359
Finding velocity (delta)V [ENDORSED]
If a problem asks to find velocity using the Heisenberg equation, it seems that we typically have to find (delta)P and then divide by mass (m) (since momentum(delta)P= mass (m) x (delta)V). When we divide by mass, do we always assume it is the mass of the electron (9.11x10^-31 kg)?
- Tue Apr 17, 2018 7:55 pm
- Forum: DeBroglie Equation
- Topic: HW 1.39 [ENDORSED]
- Replies: 8
- Views: 1045
Re: HW 1.39 [ENDORSED]
I would think you would use wavelength= h/mv. Where h= plancks constant (Js), m=mass (g), v= velocity (m/s). At first convert ounces to grams and mph to m/s, then I would use the equation mentioned.
- Tue Apr 17, 2018 7:49 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: h-bar [ENDORSED]
- Replies: 7
- Views: 1373
h-bar [ENDORSED]
In the Heisenberg uncertainty equation, does h-bar basically mean plancks constant divided by 2pi? Will this number always be the same/constant or are there instances where its different?
- Sat Apr 14, 2018 2:36 pm
- Forum: Photoelectric Effect
- Topic: ENERGY PER MOLE OF PHOTONS [ENDORSED]
- Replies: 3
- Views: 393
Re: ENERGY PER MOLE OF PHOTONS [ENDORSED]
I would imagine since 1 mole= 6.022x10^23 "things"/atoms, and photons contain packets of energy aka packets of electrons (absorbed or emitted). I may be wrong but this is how I interpreted it?
- Sat Apr 14, 2018 2:25 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: 1.3 Atomic Spectra- Spectral lines
- Replies: 4
- Views: 265
Re: 1.3 Atomic Spectra- Spectral lines
Oh okay, thank you! For the 2 different series (Balmer and Lyman), do these two series just represent/determines which portion of the spectrum you are looking at? Like visible light is within the Balmer series and the Lyman series are those in the UV region?
- Fri Apr 13, 2018 11:41 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: 1.3 Atomic Spectra- Spectral lines
- Replies: 4
- Views: 265
1.3 Atomic Spectra- Spectral lines
Hi,
I'm currently reading the section about spectral lines, etc. and I'm confused as to what "n" stands for? For example, the Rydberg equation has certain variables (n1 and n2). What do they represent?
I'm currently reading the section about spectral lines, etc. and I'm confused as to what "n" stands for? For example, the Rydberg equation has certain variables (n1 and n2). What do they represent?
- Tue Apr 10, 2018 11:19 pm
- Forum: Significant Figures
- Topic: Scientific notation [ENDORSED]
- Replies: 7
- Views: 997
Re: Scientific notation [ENDORSED]
In class, he also mentioned how we wouldn't get negatively impacted for the quizzes if we weren't to follow sig figs. I assume this may also apply to tests as well?
- Tue Apr 10, 2018 11:15 pm
- Forum: Limiting Reactant Calculations
- Topic: General Process [ENDORSED]
- Replies: 3
- Views: 497
Re: General Process [ENDORSED]
In my discussion section, I remember that we were taught another way of finding the limiting reactant. We first find the amount of moles from the masses (of each element) given and then divide by the coefficients in the balanced equation. The calculation with the smallest result ended up being the l...
- Tue Apr 10, 2018 11:02 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Formula Units
- Replies: 6
- Views: 16805
Re: Formula Units
Based off previous posts, formula units appear to be salts and/or the number of "objects"/"things" etc.? From the online definition: "A formula unit indicates the lowest whole number ratio of ions in an ionic compound." Units within the formula are atoms of the element ...
- Sun Apr 08, 2018 5:19 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing equations with fractions [ENDORSED]
- Replies: 13
- Views: 1652
Re: Balancing equations with fractions [ENDORSED]
I think this idea is also similar to when we create the empirical formulas. The idea to keep the stoichiometric coefficients whole numbers. For example, if after dividing the moles of a particular element by the smallest number of moles there is still a fractional number, then you would also multipl...
- Fri Apr 06, 2018 11:19 am
- Forum: Limiting Reactant Calculations
- Topic: General Process [ENDORSED]
- Replies: 3
- Views: 497
General Process [ENDORSED]
With regard to limiting reagents, is it best to just test each reactant and relate it to the products? Or is there a simpler way to approaching these types of problems such as certain giveaways that will determine which reactant is limiting?
- Fri Apr 06, 2018 11:15 am
- Forum: Molarity, Solutions, Dilutions
- Topic: G.5 [ENDORSED]
- Replies: 3
- Views: 582
G.5 [ENDORSED]
Can someone explain why in part a of G.5 theres the multiplying of Na2CO3 mol and dividing of Na moles such as: v= (2.15E-3 mol Na)(1 mol Na2CO3)/(0.0797 mol/L)(2 mol Na) ? I'm confused as I know the formula is Volume=mol/conc and I see that it's asking in relation to Na. But then theres the compoun...