Search found 19 matches
- Mon Dec 04, 2017 7:24 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Drawing Coordination Compounds
- Replies: 5
- Views: 1232
Re: Drawing Coordination Compounds
Yes! Drawing them should be similar to drawing Lewis Structures. You just have to be a little bit careful because transition metals have different valence electrons, so you also have to pay attention to that. Also, pay attention to what atoms are specifically bonded to the transition metal/Lewis aci...
- Mon Dec 04, 2017 7:15 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: What is 1/K? [ENDORSED]
- Replies: 4
- Views: 1512
Re: What is 1/K? [ENDORSED]
If a reaction is reversed, for example:
A + B ⇌ C is flipped to C ⇌ A + B, and you are given the K of the original reaction, and you are asked for the K value of the second reaction, you simple get the reciprocal of the original K value.
Hope this helps!
A + B ⇌ C is flipped to C ⇌ A + B, and you are given the K of the original reaction, and you are asked for the K value of the second reaction, you simple get the reciprocal of the original K value.
Hope this helps!
- Mon Dec 04, 2017 7:07 pm
- Forum: Biological Examples
- Topic: Cooridnate compound dentate
- Replies: 2
- Views: 574
Re: Cooridnate compound dentate
The best way to figure out what kind of dentate a molecule is is to draw out the molecule out. Once you have it drawn out, then you should observe on how many atoms have negative formal charges or lone pairs, then count the sites where this is present, then that should be the type of dentate it is.
- Sun Nov 26, 2017 11:34 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: S Character Influencing Bond Angles
- Replies: 2
- Views: 461
Re: S Character Influencing Bond Angles
The number of areas of electron density is usually what you should look at when determining the bond angles, but you should also pay attention to what kind of areas of electron density they are (EX: lone pairs vs. bonds; lone pairs usually repel other atoms more, therefore the bond angles are less t...
- Sun Nov 26, 2017 11:29 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: CH2Cl2 polarity
- Replies: 2
- Views: 1141
Re: CH2Cl2 polarity
Since the carbon atom isn't surrounded solely by hydrogen atoms or chlorine atoms, it isn't considered symmetrical anymore. You should also take into account the distribution of the charges.
- Sun Nov 19, 2017 11:40 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: AX2E2
- Replies: 2
- Views: 1068
Re: AX2E2
When there is a lone pair, it tends to repel the other bonds more, therefore making the angles of the bonds less, because the lone pair naturally just pushes the rest away further, but it all nears the same degrees of angle, so they'll usually just express the angle as <90 or <120.
- Sun Nov 19, 2017 11:38 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 4.25 (Polarity)
- Replies: 4
- Views: 614
Re: 4.25 (Polarity)
Drawing out the molecular structure, then proceeding to see if the dipole moments cancel each other out. If they cancel each other out, then they are non polar, if not, then the molecule is polar. Also, all hydrocarbons are non polar!
- Sun Nov 12, 2017 10:56 pm
- Forum: Lewis Structures
- Topic: When to use a double bond or triple bond [ENDORSED]
- Replies: 6
- Views: 47335
Re: When to use a double bond or triple bond [ENDORSED]
What I usually do is create the lewis structure by starting with all single bonds and drawing in the valence electrons, then if I notice the electrons are unpaired, then I'll start creating bonds, then I'll focus on the formal charges. I always try to see that the central atom has a formal charge cl...
- Sun Nov 12, 2017 10:52 pm
- Forum: Lewis Structures
- Topic: Central Atom? [ENDORSED]
- Replies: 7
- Views: 2719
Re: Central Atom? [ENDORSED]
Hydrogen cannot be the central atom mainly because it only has one electron, therefore can only form one bond, and when an atom is the central that usually implies that it must be able to form more than one bond. It could be considered as an exception considering it isn't able to bond to as many ato...
- Sun Nov 05, 2017 11:36 pm
- Forum: Ionic & Covalent Bonds
- Topic: How to easily tell between Ionic and Covalent bonds?
- Replies: 8
- Views: 1493
Re: How to easily tell between Ionic and Covalent bonds?
The electronegativity values will most likely be given to us, but it will probably be helpful to memorize that from 0.0 - 0.2, the bond is considered non-polar covalent. When it is 0.3 - 1.4, it is polar covalent, and lastly, when it is greater than 1.5, it is ionic.
Hope that helps!!
Hope that helps!!
- Sun Nov 05, 2017 11:10 pm
- Forum: Resonance Structures
- Topic: Resonance vs. Isomers [ENDORSED]
- Replies: 3
- Views: 1545
Re: Resonance vs. Isomers [ENDORSED]
Isomers are molecules that share the similar chemical formulas but their atoms are structured and arranged differently. Consequently, the purpose of these molecules differ as well. Resonance structures show molecules or ions that have the same chemical formulas as well, but simply different structur...
- Mon Oct 30, 2017 12:42 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Exercise 1.45
- Replies: 4
- Views: 617
Re: Exercise 1.45
The +/- indicates that theres a range of indeterminacy in where the velocity of an electron (or whatever molecule there is) because once a photon or source of energy hits the electron, the momentum of both are much more similar than to what a photon would have to a baseball would have, and the direc...
- Sun Oct 29, 2017 11:57 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Test 3 [ENDORSED]
- Replies: 5
- Views: 786
Re: Test 3 [ENDORSED]
The test will be covering the last bit of chapter 1 and most of chapter 2! So basically the second of half of the second outline he has posted on the chem 14a website (which is super helpful to look at before the test!) and things like heisenberg's equation, electron configuration, wave functions, a...
- Wed Oct 18, 2017 11:09 am
- Forum: DeBroglie Equation
- Topic: λ=c/v VS. λ=h/mv
- Replies: 9
- Views: 12799
Re: λ=c/v VS. λ=h/mv
De Broglie's equation is used for particles with mass, like electrons, protons, or bigger items, while the equation of λ=c/v, would only be used for massless particles, such as photons. If you were to use De Broglie's equation for a massless particle, you would end up with a 0 in the denominator. Ho...
- Wed Oct 18, 2017 11:05 am
- Forum: DeBroglie Equation
- Topic: 1.39 Help
- Replies: 5
- Views: 620
Re: 1.39 Help
Are we expected to know the conversion from miles to kilometres? It's not on the equation and constant sheet either! I don't think we are (I think, or at least hope, that on the midterm or on the final, conversion factors that are a little bit more out of the blue will be given) but it might be sup...
- Wed Oct 18, 2017 10:56 am
- Forum: Photoelectric Effect
- Topic: Energy of Photon [ENDORSED]
- Replies: 9
- Views: 2402
Re: Energy of Photon [ENDORSED]
Since the equation for kinetic energy is E(photon) - E(energy required to remove e-) = E(excess) = Ek, if the energy of the photon would cancel out the threshold energy/work function and it would lead the kinetic energy to equalling zero. So, the electron would be emitted with Ek = 0! Hopefully that...
- Wed Oct 18, 2017 10:49 am
- Forum: DeBroglie Equation
- Topic: When to use De Broglie Equation [ENDORSED]
- Replies: 11
- Views: 5131
Re: When to use De Broglie Equation [ENDORSED]
^^^ To elaborate more, De Broglie's equation is typically used when the object's wavelength we are told to look for has mass. On the other hand, if we're dealing with massless particles like photons, we then use c=λν or E=hν. But in my discussion section, we were also told that we could use the c=λν...
- Sun Oct 08, 2017 3:47 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing Chemical equations too slow... any advice? [ENDORSED]
- Replies: 18
- Views: 3697
Re: Balancing Chemical equations too slow... any advice? [ENDORSED]
Keeping a list of the number of atoms for each element is super helpful! I usually have two charts or tables for the reactants and the products and I'll cross them off and rewrite the number of atoms as I change the coefficients in the balanced equations. I also usually start off balancing the eleme...
- Sun Oct 08, 2017 3:32 pm
- Forum: Empirical & Molecular Formulas
- Topic: Empirical Coefficients [ENDORSED]
- Replies: 12
- Views: 5603
Re: Empirical Coefficients [ENDORSED]
From what I learned you round up when its bigger than .5 and round down when its smaller than .5 but what if the last digit is exactly 5? When we discussed rounding in my discussion section, we talked about how if it's exactly .5, you would round to the nearest even number, so if it was 3.25, you w...