Search found 67 matches
- Thu Dec 17, 2020 1:23 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Tetrahedral molecular shape
- Replies: 10
- Views: 1736
Re: Tetrahedral molecular shape
The first cases can be applied because the electrons align themselves in a 2d shape in a way, However, I believe that determining the bond angles for tetrahedral is well beyond our scope for chemistry as its far ahead and complicated.
- Thu Dec 17, 2020 1:21 am
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Why isn't HF a strong acid?
- Replies: 23
- Views: 7136
Re: Why isn't HF a strong acid?
It is not a strong acid because the bond between H and F is relatively strong so the bond does not break easily because the F ionic radii is relatively small thus since the bonds do not break easily, it is considered a weak acid.
- Thu Dec 17, 2020 1:19 am
- Forum: Naming
- Topic: Naming Coordination Complexes
- Replies: 4
- Views: 381
Re: Naming Coordination Complexes
By breaking down whats in the coordination sphere and seeing what goes where is a good start. First look whats in the brackets and name appropriately and treat it as its own separate thing, then name the rest like usual. Breaking it into small pieces can help form the larger picture.
- Thu Dec 17, 2020 1:17 am
- Forum: Sigma & Pi Bonds
- Topic: Pi Bonds
- Replies: 18
- Views: 755
Re: Pi Bonds
Just covalent bonds because in covalent bonds, electrons are shared thus, orbitals are overlapped so they can share. But with ionic bonds, the electrons are transferred from one element to the next so there is essentially no sharing
- Thu Dec 17, 2020 1:15 am
- Forum: Ionic & Covalent Bonds
- Topic: Ionic vs Covalent Bonds
- Replies: 9
- Views: 578
Re: Ionic vs Covalent Bonds
By comparing electro negativities, if you do not have a chart of their electro negativities handy, then by looking at the periodic table can help you. The further away the elements are from each other, like on the opposite side, then they are most likely ionic but if they are close to each other the...
- Thu Dec 17, 2020 1:12 am
- Forum: Properties of Electrons
- Topic: Difference between electrons and light properties
- Replies: 5
- Views: 678
Re: Difference between electrons and light properties
I believe they shouldn't really be compared in that sense because there are many other differences that can be made, all that we need to know is that they share some characteristics like being a wave and a photon but thats the extent of their similarities while the differences are abundant.
- Thu Dec 17, 2020 1:10 am
- Forum: Properties of Light
- Topic: Wavelength
- Replies: 26
- Views: 1208
Re: Wavelength
It depends on what the question is asking for, sometimes it asks for nm but most of the time it asks for it in meters. However, if you were to use it in other calculations, make sure it is always in meters.
- Thu Dec 17, 2020 1:07 am
- Forum: Limiting Reactant Calculations
- Topic: General Limiting Question
- Replies: 9
- Views: 826
Re: General Limiting Question
The limiting reactants always limits how much product is made. Think of it like if you make a turkey sandwich, if you have endless bread and vegetables and 4 slices of turkey, the turkey will limit how many sandwiches are made.
- Fri Dec 11, 2020 11:20 pm
- Forum: Naming
- Topic: tetraamminedichloronickel (II) example from review
- Replies: 3
- Views: 561
Re: tetraamminedichloronickel (II) example from review
I think if they are like right next to each other it is cis but when it is across it is trans but the naming should be the same for both regardless where they are placed.
- Fri Dec 11, 2020 11:18 pm
- Forum: Electronegativity
- Topic: Be vs Cl
- Replies: 49
- Views: 2666
Re: Be vs Cl
remember that going across a period, electronegativity increases but going down a group it decreases, Since Cl is more to the right its electronegativity is higher.
- Fri Dec 11, 2020 11:17 pm
- Forum: Octet Exceptions
- Topic: Octet Exceptions and Expanded Octet Calculation
- Replies: 3
- Views: 485
Re: Octet Exceptions and Expanded Octet Calculation
Elements in the 2p must have an octet. The elements H,He,Be,Li never have an octet and B and Al usually have an incomplete octet. But as the person said above, elements in the 3p can expand their octets.
- Fri Dec 11, 2020 11:16 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: shielding and penetrating
- Replies: 5
- Views: 496
Re: shielding and penetrating
The electrons in the inner levels take the brunt of the nuclear charge and the e- in the outer shells feel less of the effect thus they can escape more easily.
- Fri Dec 11, 2020 11:13 pm
- Forum: DeBroglie Equation
- Topic: De broglie equation versus E=hv
- Replies: 10
- Views: 744
Re: De broglie equation versus E=hv
Use De brogiles for molecules that have a rest mass and use E=hv for electromagnetic radiation like light photons
- Fri Dec 11, 2020 11:03 pm
- Forum: Einstein Equation
- Topic: units for E=hv
- Replies: 21
- Views: 1067
Re: units for E=hv
It can be J/photon or J/atom, depends on the context and what the question is looking for.
- Fri Dec 11, 2020 11:01 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bent vs Angular
- Replies: 20
- Views: 875
Re: Bent vs Angular
Bent and angular both describe the same shape but I mostly see lavelle use bent so I would use that
- Fri Dec 11, 2020 11:00 pm
- Forum: Hybridization
- Topic: AsF³ Hybridization
- Replies: 6
- Views: 672
Re: AsF³ Hybridization
It is sp3 hybridized because it will make 3 bonds with the fluorines and make one lone pair with itself so it should be sp3 because it has 4 areas of e- density.
- Fri Dec 11, 2020 10:59 pm
- Forum: Sigma & Pi Bonds
- Topic: Rotation
- Replies: 16
- Views: 864
Re: Rotation
Yes, as long as you know there is one pi bond and not just pi bonds then I think it is safe to assume its at least a double bond.
- Fri Dec 11, 2020 10:57 pm
- Forum: Ionic & Covalent Bonds
- Topic: CO2 vs CS2
- Replies: 8
- Views: 1409
Re: CO2 vs CS2
Sulfur is less electronegative than oxygen so it puts up "less of a fight" than the oxygens which makes the dipole moments weaker than the CO2
- Tue Dec 08, 2020 10:00 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Energy of orbitals
- Replies: 2
- Views: 252
Re: Energy of orbitals
Yes they would have essentially the same energy in their respective sub-shells. But orbitals in the same shell would have differing energy levels.
- Tue Dec 08, 2020 9:59 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Why do we need this?
- Replies: 5
- Views: 456
Re: Why do we need this?
It is important to know because it tells us that an e- needs space in order for it to exist. It also calls into question how we cannot definitely know where the electron is and know how fast it is going at the same time. It also shows how photon and electron interaction can greatly change the outcom...
- Tue Dec 08, 2020 9:58 pm
- Forum: Photoelectric Effect
- Topic: Negative or Positive
- Replies: 2
- Views: 267
Re: Negative or Positive
The photoelectric effect has to do when a photon comes into contact with electrons and either knocks them off or does not. Maybe you are thinking about when an e- goes down energy levels and the energy is negative as it was 0 prior to it going down.
- Tue Dec 08, 2020 9:56 pm
- Forum: DeBroglie Equation
- Topic: Avogadro's Number
- Replies: 21
- Views: 1548
Re: Avogadro's Number
It tells us the number of photons, electrons, molecules, atoms, etc. Anything really small and it gives it to us per mol and it is 6.022x10^23. We use it when it asks how many photos per mole or how much mass a specific molecule has.
- Tue Dec 08, 2020 9:53 pm
- Forum: Properties of Light
- Topic: Frequency and amplitude
- Replies: 7
- Views: 533
Re: Frequency and amplitude
There really is not a set in stone relationship between the two because I believe that amp is related to intensity so there really is not a clear connection between the two.
- Tue Dec 08, 2020 9:52 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Constant
- Replies: 4
- Views: 304
Re: Rydberg Constant
Since the constant is used only really two times for our purposes, I would say use the one that is on the formula sheet. If professor lavelle did not really make a difference then I think we shouldn't really need to worry about it.
- Tue Dec 08, 2020 9:50 pm
- Forum: Lewis Acids & Bases
- Topic: general conceptual question
- Replies: 9
- Views: 713
Re: general conceptual question
Well first I classify if there are any strong acids present then I would see which molecule has the weaker bond with the H proton that is going to break off and the one with the weaker bond I classify as being the stronger one.
- Tue Dec 08, 2020 9:48 pm
- Forum: Lewis Acids & Bases
- Topic: Water
- Replies: 63
- Views: 2684
Re: Water
Water is amphoteric, it depends on the context like if it is reacting with a base or an acid and it will act accordingly.
- Mon Dec 07, 2020 7:24 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric Compounds
- Replies: 4
- Views: 543
Re: Amphoteric Compounds
Yes, those molecules can act both as an acid or a base but it entirely depends on the context like if it is reacting with a base or an acid, if its in water is the environment demanding it to act a certain way, and seeing if the solutions pH can affect it in any way.
- Mon Dec 07, 2020 7:22 pm
- Forum: Amphoteric Compounds
- Topic: amphoteric oxides on periodic table
- Replies: 5
- Views: 266
Re: amphoteric oxides on periodic table
One method that can take some time is putting that molecule and reacting it with water and seeing if the products make sense and applying the rules like if it is stable, did it produce hydronium or hydroxide and so forth.
- Mon Dec 07, 2020 7:21 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Anion Stabilization
- Replies: 4
- Views: 227
Re: Anion Stabilization
So since Cl has the highest electronegativity, it pulls those electrons more compared to Br and I. It helps with electron repulsion because it is more spread out over the molecule and is not as concentrated in one place and therefore makes it more stable.
- Mon Dec 07, 2020 7:19 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: neutralization reactions
- Replies: 5
- Views: 273
Re: neutralization reactions
I think that for our purposes, it will produce a salt and water. This is because the strong acids and strong bases we are familiar with let go of the hydronium and the hydroxide which they have and these molecules go and form the water and the salt.
- Mon Dec 07, 2020 7:16 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Stability of Anions Considering Strengths of ACids
- Replies: 4
- Views: 680
Re: Stability of Anions Considering Strengths of ACids
If an anion is delocalized it is more stable. Think of it like its spreading across the whole molecule and if it is delocalized more, then it isn't just concentrated in one area. Thus, when it is more stable, the molecule will be more inclined to let go of the proton because it wont upset the balanc...
- Mon Dec 07, 2020 7:13 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Negative pH of acid
- Replies: 16
- Views: 666
Re: Negative pH of acid
pH can exceed the 0 to 14 but as Lavelle mentioned, we wont have to worry about it since we mostly deal with the concepts of this class and not so much the equilibrium equations so we do not have to worry about it.
- Mon Dec 07, 2020 7:12 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Why is HF not classified as a strong acid?
- Replies: 19
- Views: 981
Re: Why is HF not classified as a strong acid?
It is not classified as a strong acid due to how the strength of the H-F bond. Since it is stronger than the rest of the halogens, it does not break as easily therefore it does not dissociate nearly as much as the strong acids.
- Sun Dec 06, 2020 1:34 am
- Forum: Sigma & Pi Bonds
- Topic: Sigma and Pi Bonds
- Replies: 24
- Views: 1080
Re: Sigma and Pi Bonds
Every bond has a sigma bond which is easy to remember. Double bond therefore has a sigma and a pi bond and triple has a sigma and 2 pi bonds. Therefore to remember, add a pi bond for every extra bond then add them up to see if it equals the total amount of bonds.
- Sun Dec 06, 2020 1:32 am
- Forum: Ionic & Covalent Bonds
- Topic: Polar and Nonpolar
- Replies: 37
- Views: 1678
Re: Polar and Nonpolar
A good thing to do if you have time is to draw the lewis structure of the formula and check to see if the bonds are polar and nonpolar to see if it all cancels out. If the central atom however, it surrounded by atoms that are all the same in symmetrical positions then all the polarity should cancel ...
- Sun Dec 06, 2020 1:28 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: d orbitals
- Replies: 11
- Views: 1557
Re: d orbitals
Hi, so each orbital including d orbitals can hold up to max of 2 electrons due to the pauli exclusion principle. It happens to be 5 due to the ml being -2,-1,0,1,2 and the periodic table in the transition metal area can help visualize that.
- Sun Dec 06, 2020 1:26 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Energy level of orbitals
- Replies: 5
- Views: 347
Re: Energy level of orbitals
Yes it does go in that order and the electrons will be filled up accordingly, however there are some exceptions such as when 4s goes before 3d or the transition metals Cr and Cu are filled up differently in order to achieve symmetry and a lower energy state. Thus, s<p<d<f is correct for most atoms, ...
- Sun Dec 06, 2020 1:22 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: how many orbitals in n=2
- Replies: 12
- Views: 9414
Re: how many orbitals in n=2
As those stated above it will have 4 orbitals because when n=2, the l=0,1 (Up to n-1) then ml ranges from -l,+l so it would just be 0 for l=0 and then m=-1,0,1 and added them up equals 4 orbitals.
- Sun Dec 06, 2020 1:19 am
- Forum: Properties of Light
- Topic: Photoelectric Effect
- Replies: 14
- Views: 810
Re: Photoelectric Effect
If there is an excess of electrons then the electrons have to go somewhere will all that excess energy and they will have a kinetic energy(Conservation of energy).
- Sun Dec 06, 2020 1:18 am
- Forum: Properties of Light
- Topic: Is c always the speed of light?
- Replies: 92
- Views: 4930
Re: Is c always the speed of light?
Based on the formulas and constants sheet, c in this class will stand for the speed of light.
- Sun Dec 06, 2020 1:16 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Atomic Spectroscopy, Energy level
- Replies: 2
- Views: 209
Re: Atomic Spectroscopy, Energy level
When thinking about negative and positive energies try to associate it with totals. Its negative because its total energy has decreased from n=4 to n=2 therefore its total energy it had decreased and the opposite is true for positive energy.
- Sun Dec 06, 2020 1:13 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Energy levels
- Replies: 5
- Views: 418
Re: Energy levels
As the person said above, it should lead to the same answer but one can be more useful to use than the other it all depends on the context and your organization but either one is good.
- Sun Dec 06, 2020 1:12 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Photons and Electrons
- Replies: 3
- Views: 350
Re: Photons and Electrons
A good thing to remember is that a photon will act directly with another electron so if there are one million photons it will at most interact with one million electrons.
- Sun Dec 06, 2020 1:09 am
- Forum: Properties of Electrons
- Topic: intensity vs energy
- Replies: 29
- Views: 3180
Re: intensity vs energy
Energy and frequency are directly related while energy and intensity are not related as intensity only deals with the number of photos so it is a false statement.
- Fri Dec 04, 2020 10:24 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: chelate
- Replies: 7
- Views: 376
Re: chelate
Being able to rotate is a property unique to sigma bonds since pi bonds are locked so if it is able to rotate then it is single bonded.
- Fri Dec 04, 2020 10:23 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydentate Ligands
- Replies: 3
- Views: 124
Re: Polydentate Ligands
A great way to find out if it is polydentate is by drawing the lewis structure of the molecule and then filling in the bonds and the free pairs. Once you have drawn them correctly you can easily find where it can bond due to the free pair electrons and if it is more than 2 then it is polydentate.
- Fri Dec 04, 2020 10:21 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Number for square planar molecule
- Replies: 3
- Views: 216
Re: Coordination Number for square planar molecule
What the other have said above can also apply to other molecules as well! such as if you know the compound is in a tetrahedral shape and geometry then the coordination compound is 4.
- Fri Dec 04, 2020 10:19 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Oxidation Number
- Replies: 6
- Views: 305
Re: Oxidation Number
Try treating the atoms inside the molecule as one entire molecule to better visualize such as NaCl. We know Cl is -1 and as a whole it is negative so Na must be +1. Try thinking like this so if Cl2 add up to -2 then the brackets should be +2 and then break it down further to find the TM cation charge.
- Fri Dec 04, 2020 10:16 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: ligands
- Replies: 11
- Views: 436
Re: ligands
NH3 a neutral molecule because all of its formal charges add up to 0 but remains a ligand due to N free pair of electrons.
- Thu Dec 03, 2020 12:32 pm
- Forum: Naming
- Topic: Ligand Names Table on Final
- Replies: 10
- Views: 469
Re: Ligand Names Table on Final
It is not a given document we would usually get so we will not receive a chart. We should memorize the rules on how to name them and know the basic molecules in order to do well in naming them.
- Thu Dec 03, 2020 12:29 pm
- Forum: Naming
- Topic: Naming order, Penta Amine Chloro Cobalt (II) Chloride Dihydrate
- Replies: 2
- Views: 141
Re: Naming order, Penta Amine Chloro Cobalt (II) Chloride Dihydrate
Chloro comes before cobalt because its a ligand and it comes first. Ammine comes before cobalt due to ligands being listen in alphabetical order. To find the charge of the TM Cation, check and see what all the atoms charges add up to and check to see the total charge then assign that TM its charge a...
Re: Ligands
Also, the ligands that are most prevalent in the problems that we see such as OH- and NH3, basically small easy molecules with free electron pairs should be memorized as they pop up the most often.
- Thu Dec 03, 2020 12:23 pm
- Forum: Naming
- Topic: Ferrate or iron?
- Replies: 8
- Views: 623
Re: Ferrate or iron?
I believe that it is called ferrate instead of something else because it has a +2 charge therefore it will end in -ate. I believe it is not called ironate due to it being defined, i.e. something we should memorize.
- Thu Dec 03, 2020 12:20 pm
- Forum: Biological Examples
- Topic: Examples of Square Planar Molecules?
- Replies: 9
- Views: 2715
Re: Examples of Square Planar Molecules?
To add onto what the other have said above, since for example XeF4 has 2 free electron pairs, it is able to create two more covalent bonds instead of the usual 1 extra covalent bond that we usually see.
- Thu Dec 03, 2020 12:18 pm
- Forum: Biological Examples
- Topic: Hemoglobin vs. Myoglobin
- Replies: 30
- Views: 1224
Re: Hemoglobin vs. Myoglobin
Myoglobin is primarily found within the muscle tissue and transports 1 O2 while Hemoglobin is found in the blood and can be made up of 4 myoglobin and can therefore transfer 4 O2. However, they both share the similarity of having the TM Cation of Iron.
- Thu Dec 03, 2020 12:16 pm
- Forum: Biological Examples
- Topic: Co - VitB12
- Replies: 7
- Views: 442
Re: Co - VitB12
The Cobalt is within the molecule and is therefore part of the vitamin. The way it interacts with other molecules, i.e. how it manages its electron bonds and free elections make it unique and therefore vital to the human body.
- Thu Dec 03, 2020 12:14 pm
- Forum: Naming
- Topic: halide ion naming
- Replies: 2
- Views: 153
Re: halide ion naming
Professor Lavelle mentioned we would most likely see the chloro more often but that chlorido is also acceptable as well. When the halide is connected to the TM Cation just drop the -ide or the last letter and an o.
- Tue Dec 01, 2020 7:37 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: charge of oxalato
- Replies: 4
- Views: 951
Re: charge of oxalato
Just like the polyatomic ions, I believe there are certain charges of common molecules that need to be memorized since they appear frequently like sulfate and carbonate.
- Tue Dec 01, 2020 7:33 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: 4 ligands shape
- Replies: 5
- Views: 273
Re: 4 ligands shape
I believe see saw is not included because although it has 4 bonds in it, it is very uncommon for a molecule to take this shape as the tetrahedral or the square planar shape are much more desirable due to lower repulsions.
- Fri Nov 27, 2020 8:18 pm
- Forum: Lewis Structures
- Topic: Ring structures
- Replies: 4
- Views: 134
Re: Ring structures
I believe that for our purposes, when we see a molecule with 6 carbon atoms, it will most likely be in a ring structure
- Fri Nov 20, 2020 10:46 pm
- Forum: Sigma & Pi Bonds
- Topic: Triple bond?
- Replies: 21
- Views: 833
Re: Triple bond?
Every bond has a sigma bond and then add pi bonds accordingly so the sum of the sigma and the pi bounds should equal the total amount of bonds on the given atom.
- Thu Nov 12, 2020 10:15 pm
- Forum: Lewis Structures
- Topic: textbook problem 2B #9
- Replies: 4
- Views: 204
Re: textbook problem 2B #9
A good note to have when doing these types of problems is looking at a chart of the electro negativities of the atoms and try to use the rough guidelines. Also if the atoms seem to be far away on the periodic table, it is a good chance that they will be ionic as well.
- Thu Nov 12, 2020 10:13 pm
- Forum: Lewis Structures
- Topic: Nitrite structure
- Replies: 4
- Views: 288
Re: Nitrite structure
Also, a good note to have is that Nitrogen usually likes to have one pair of electrons to itself. I believe this is so that it can have a formal charge of 0 but having one single and one double would make the formal charges more neat and close to zero.
- Wed Nov 11, 2020 7:39 pm
- Forum: Lewis Structures
- Topic: Formal Charge
- Replies: 5
- Views: 180
Re: Formal Charge
As the person above me put it and to expand on it, if you do the formal charge for every atom you can catch certain mistakes like if a very electronegative atom has a +1 or +2 formal charge or if some formal charges seem out of line and therefore extremely unlikely to exist. Doing it is like checkin...
- Wed Nov 11, 2020 7:34 pm
- Forum: Lewis Structures
- Topic: Elements in different blocks and forming an octate
- Replies: 2
- Views: 87
Re: Elements in different blocks and forming an octate
I would think that as the person said above, that they want to fill out all their orbitals up. I think this can explain as to why elements in period 3 can have expanded octets because they would not mind filling up their orbitals as I believe thats the main goal.
- Wed Nov 11, 2020 7:32 pm
- Forum: Lewis Structures
- Topic: Finding Lewis Structure based on oxidation numbers
- Replies: 2
- Views: 107
Re: Finding Lewis Structure based on oxidation numbers
Regarding what you said, I would think that formal charge and oxidation numbers are pretty similar and so what I did was chose the resonance structure that had the formal charge that was the closest to the oxidation number I got.
- Thu Nov 05, 2020 1:46 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Why is the 4s state filled before the 3d state?
- Replies: 14
- Views: 734
Re: Why is the 4s state filled before the 3d state?
So like am I getting this right correct me if I am wrong, initially the 4s orbital is lower in energy than the 3d orbital so it gets filled up first. But once the 3d orbital is half full it becomes lower in energy than the 4s as it takes away an electron from that orbital? then the 3d gets filled up...