Search found 30 matches
- Thu Dec 06, 2018 6:12 pm
- Forum: Bronsted Acids & Bases
- Topic: Acids
- Replies: 3
- Views: 456
Re: Acids
For the most part, when questions ask you to determine which compound is an "acid", they are referring to the Bronsted definition of an acid.
- Thu Dec 06, 2018 6:09 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Neutral Ligand
- Replies: 2
- Views: 285
Neutral Ligand
What makes a ligand "neutral"?
- Thu Dec 06, 2018 6:07 pm
- Forum: Conjugate Acids & Bases
- Topic: OH- vs -OH
- Replies: 3
- Views: 413
Re: OH- vs -OH
Our TA said it was purely a personal preference. There is no difference between the two so don't get too confused.
- Thu Dec 06, 2018 5:25 pm
- Forum: Biological Examples
- Topic: Biological Importance
- Replies: 1
- Views: 256
Biological Importance
Can somebody explain the biological importance of coordination compounds and how these compounds actually influence biological systems?
- Thu Dec 06, 2018 5:23 pm
- Forum: Bronsted Acids & Bases
- Topic: Identifying the difference
- Replies: 6
- Views: 599
Re: Identifying the difference
Bronsted Acids and bases are more commonly used and considered a more widely accepted definition. Just be careful with what the problem asks so you know which definition to use.
- Thu Dec 06, 2018 5:21 pm
- Forum: Bronsted Acids & Bases
- Topic: Zinc Nitrate
- Replies: 2
- Views: 408
Re: Zinc Nitrate
The formula for Zinc Nitrate is Zn(NO3)2.
Theoretically you could use Zn(OH)2 (base) and add 2HNO3 (acid) to get Zinc Nitrate and water, though I'm not sure if this is possible in real life.
Theoretically you could use Zn(OH)2 (base) and add 2HNO3 (acid) to get Zinc Nitrate and water, though I'm not sure if this is possible in real life.
- Thu Dec 06, 2018 5:18 pm
- Forum: Bronsted Acids & Bases
- Topic: Bronsted Acids and Bases
- Replies: 4
- Views: 542
Re: Bronsted Acids and Bases
Another quick (but much less reliable way) would be to think about common compounds that have just one more or one less proton. Ex: Given NH4+, try to recall a compound you've seen before (NH3) Same with OH- and H20, H30+ and H2O, HNO3 and NO3-, etc. I would only recommend using this method if you a...
- Thu Dec 06, 2018 5:12 pm
- Forum: Bronsted Acids & Bases
- Topic: Donating H protons
- Replies: 2
- Views: 371
Re: Donating H protons
It depends on if the molecule the two hydrogen atoms are attached to will be stable. Molecules tend to exist in the most stable state, so if removing the hydrogen makes the molecule unstable, it isn't likely to donate two hydrogen atoms. For example: H2SO4 is likely to lose the two hydrogen because ...
- Thu Dec 06, 2018 5:07 pm
- Forum: Bronsted Acids & Bases
- Topic: Electronegativity and Acidity
- Replies: 1
- Views: 346
Re: Electronegativity and Acidity
HF is a weak acid because fluorine is relatively small compared to the other atoms in its group. This makes the bond length shorter and therefore makes the H-F bond relatively strong. A stronger bond results in a weaker acid because HF is less likely to dissociate in to H+ and F-. I'm not exactly su...
- Sat Nov 17, 2018 9:20 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Shapes
- Replies: 4
- Views: 508
Re: VSEPR Shapes
T shaped has two pairs of unpaired electrons (AX3E2). Trigonal pyramidal has only one pair of unpaired electrons AX3E. Remember that the shape of a molecule is determined both by bonded AND unbonded pairs.
- Sat Nov 17, 2018 9:17 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape
- Replies: 2
- Views: 224
Re: Molecular Shape
Yes, VSEPR is the reason why the shapes exist. The valence shell electron repulsion is what gives molecules their geometric shape, as atoms orient themselves so that they are the farthest distance from eachother (a result of the repulsion).
- Sat Nov 17, 2018 9:14 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Model
- Replies: 3
- Views: 307
Re: VSEPR Model
Not exactly - you could memorize each individual shape based on the number of bonded and unbonded pairs. However, you are basically doing the same with the AXE notation and it's extremely helpful to know. You can memorize which AXE formula corresponds to a certain shape, which will make it easier to...
- Sun Nov 11, 2018 11:53 am
- Forum: Bond Lengths & Energies
- Topic: Strength of Bonds
- Replies: 9
- Views: 1040
Re: Strength of Bonds
Boiling and melting are both physical changes, not chemical changes. Therefore the intermolecular forces are at play - if the intramolecular forces were affected then it would be a chemical change.
- Sun Nov 11, 2018 11:48 am
- Forum: Dipole Moments
- Topic: induced-dipole
- Replies: 3
- Views: 577
Re: induced-dipole
Also note that induced dipoles are more common in compounds with a larger amount of electrons. So a compound like C6H12 would be more likely to have an induced dipole than CH4.
- Sun Nov 11, 2018 11:45 am
- Forum: Ionic & Covalent Bonds
- Topic: Covalent vs Hydrogen bond in H20
- Replies: 4
- Views: 1686
Re: Covalent vs Hydrogen bond in H20
Covalent bonds are intramolecular bonds, which would be the bonds between the oxygen and hydrogen in H2O. Due to the electronegativity difference between hydrogen and oxygen, the electron distribution becomes uneven which allows for intermolecular bonds known as hydrogen bonding.
- Sat Nov 03, 2018 9:14 am
- Forum: Lewis Structures
- Topic: How many valence electrons?
- Replies: 1
- Views: 1772
How many valence electrons?
How many valence electrons are in:
[Ar] 3d10 4s2 4p3
[Ar] 3d5 4s2
[Ar] 3d10 4s2 4p3
[Ar] 3d5 4s2
- Sat Nov 03, 2018 9:09 am
- Forum: Lewis Structures
- Topic: Electron Affinity
- Replies: 2
- Views: 295
Electron Affinity
Does electron affinity need to be taken into account when drawing Lewis Dot Structures? I briefly remember Dr. Lavelle mentioning Electron Affinity as we left lecture on Monday.
- Wed Oct 31, 2018 10:46 pm
- Forum: Lewis Structures
- Topic: The Number of Valence Electrons in Transition Metals
- Replies: 2
- Views: 391
The Number of Valence Electrons in Transition Metals
Hi, how do you know the number of valence electrons for transition metals? One of the homework questions asked "How many valence electrons are in Mn?" The answer is 7, but how can you tell?
- Fri Oct 26, 2018 4:38 pm
- Forum: Lewis Structures
- Topic: octets
- Replies: 13
- Views: 1058
Re: octets
The only elements with full octets are the noble gases. Other elements must bond to form compounds in order to get a full octet. You can use the periodic table to see how many electrons an element has based on its group number.
- Fri Oct 26, 2018 4:32 pm
- Forum: Ionic & Covalent Bonds
- Topic: Valence Electrons
- Replies: 2
- Views: 276
Re: Valence Electrons
Elements are also the most stable when they have an electron configuration similar to that of a noble gas, which is why most compounds follow the octet rule (with the exception of compounds including H, He, Li, and Be).
- Fri Oct 26, 2018 4:26 pm
- Forum: Ionic & Covalent Bonds
- Topic: Valence Electrons
- Replies: 4
- Views: 706
Re: Valence Electrons
Start by checking the element's location on the periodic table. Elements in Group 1 have one valence electron, those in group 2 have two valence electrons. Then skip to group 13, under Boron. Group 13 elements have 3 valence electrons, then group 14 has 4, group 15 has 5, and so on until you reach g...
- Sat Oct 20, 2018 12:49 am
- Forum: Trends in The Periodic Table
- Topic: Periodic Table Trends
- Replies: 5
- Views: 607
Re: Periodic Table Trends
As you go down a group, the atomic radius increases because the electrons are at larger distances from the nucleus. As you move across a row, the increased amount of protons pull the electrons closer, making it harder to remove (since protons in nucleus attract) and therefore increase IE. Moving dow...
- Sat Oct 20, 2018 12:39 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Nodes of F Orbital
- Replies: 1
- Views: 192
Nodes of F Orbital
Hi, one of the homework questions asked for how many nodes an F orbital has. Does anyone know? Also, is there a way to find out how many nodes each type has or is it just memorization?
- Sat Oct 13, 2018 1:24 pm
- Forum: Properties of Light
- Topic: The PhotoElectric Effect
- Replies: 2
- Views: 197
The PhotoElectric Effect
How does the photoelectric effect support the idea that electromagnetic radiation has properties of particles?
- Thu Oct 11, 2018 4:36 pm
- Forum: Balancing Chemical Reactions
- Topic: Test 1 and Future Tests
- Replies: 5
- Views: 761
Re: Test 1 and Future Tests
Honestly, I don't think there's any way to show your work for those questions. Maybe just show all your attempts, but even then it gets messy (since we're using pen). I doubt the TA's will care, and if they do - I'm screwed because I didn't show my work ... I just put my final answer.
- Thu Oct 11, 2018 4:30 pm
- Forum: Significant Figures
- Topic: Rounding Using Significant Figures
- Replies: 10
- Views: 1464
Re: Rounding Using Significant Figures
I've always kept significant figures running in the calculator, regardless of whether you're using multiplication, division, addition, or subtraction. While the rules above about significant figures is correct, most, if not all tests will allow the use of a calculator, so you can just do all the cal...
- Thu Oct 11, 2018 4:16 pm
- Forum: Student Social/Study Group
- Topic: Studying techniques
- Replies: 12
- Views: 812
Re: Studying techniques
I would also try using videos on Youtube. I used Youtube for the majority of AP Chem and there are a lot of quality tutorials online - many include practice problems. The textbook has some tricky wording on some of the problems so if you've never seen a certain type of problem (like limiting reactan...
- Thu Oct 04, 2018 4:27 pm
- Forum: Empirical & Molecular Formulas
- Topic: Problem F.1b
- Replies: 3
- Views: 397
Re: Problem F.1b
Our TA told us that if he was grading (which he is) he would not mark us off. However, he said that if we keep the calculations running in our calculator and round at the very end, our answer should match the answer key.
- Thu Oct 04, 2018 4:25 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Molar Masses
- Replies: 9
- Views: 555
Re: Molar Masses
Will we be allowed to use graphing calculators? Or will I have to go out and buy a scientific calculator?
- Thu Oct 04, 2018 4:23 pm
- Forum: SI Units, Unit Conversions
- Topic: Homework Questions [ENDORSED]
- Replies: 14
- Views: 1188
Re: Homework Questions [ENDORSED]
Will homework always be due on Friday during the lecture? Or will we switch to turning in HW to the TA during our discussion period? Just wondering because what if we have to turn in homework that wasn't covered yet (in case our lecture is after our discussion period).