Search found 31 matches
- Wed Jun 13, 2018 7:19 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Strength of Acid and Bases
- Replies: 3
- Views: 473
Re: Strength of Acid and Bases
I would generally just refer to pH when it talks about being less acidic unless they specifically mention pKa's. Just easier to understand.
- Wed Jun 13, 2018 7:15 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric Oxides
- Replies: 4
- Views: 745
Re: Amphoteric Oxides
I was just wondering if we had to memorize the amphoteric oxides, or if there's a method of determining them using the periodic table? There is the diagonal trend that Lavelle showed us in class on the periodic table. I would just use that. Just google, amphoteric compounds periodic table. It will ...
- Wed Jun 13, 2018 7:12 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Strong or weak acids/ bases
- Replies: 6
- Views: 2065
Re: Strong or weak acids/ bases
The easiest way to do this is just memorize the 7 strong acids and 8 strong bases. Anything else is weak pretty much. The strong acids are HCl, HBr, HI, HNO3, HClO4, HClO3, H2SO4, H2SeO4. The strong bases are NaOH, KaOH, CsOH, Can(OH)2, Sr(OH)2, RbOH, Ba(OH)2
- Wed Jun 13, 2018 7:06 pm
- Forum: Conjugate Acids & Bases
- Topic: No Proton Transferred? HW Problem
- Replies: 4
- Views: 722
Re: No Proton Transferred? HW Problem
I'm pretty sure a proton was transferred around since the hydrogen's are being moved around. What problem is this?
- Wed Jun 13, 2018 7:02 pm
- Forum: Conjugate Acids & Bases
- Topic: HW: 12.17
- Replies: 4
- Views: 887
Re: HW: 12.17
Can someone explain why BaO is basic and As2O3 and Bi2O3 amphoteric? As and Bi are metalloids and can act as either acids or bases. And BaO is basic because if you look at the reaction of BaO + H2O = Ba(OH)2, it forms hydroxide compounds meaning it s gonna be a basic compound. The general rule of t...
- Wed Jun 13, 2018 6:55 pm
- Forum: Conjugate Acids & Bases
- Topic: 12.47
- Replies: 2
- Views: 505
Re: 12.47
I'm pretty sure Ka and Kb values will be given. Or at least a table will be given. He has not said anything about having to memorize these values. Generally for these types of problems, they are usually given.
- Wed Jun 13, 2018 6:52 pm
- Forum: Conjugate Acids & Bases
- Topic: 12.3a
- Replies: 4
- Views: 655
Re: 12.3a
What does it mean to write the proton transfer equilibria? It basically means write the equilibrium equation. So for example, 3a, the proton transfer equilibria is H2SO4(aq) + H2O(l) (equilibrium sign) H3O+ (aq) + HSO4-(aq). By writing this equation, you are showing how the proton or the hydrogen f...
- Sun May 27, 2018 10:46 pm
- Forum: Coordinate Covalent Bonds
- Topic: Polar Covalent vs. Unequally Shared
- Replies: 3
- Views: 1304
Re: Polar Covalent vs. Unequally Shared
A polar covalent bond means there is unequal sharing. A regular covalent bond means that there is equal sharing of electrons. So a covalent bond with unequal sharing is a polar covalent bond.
- Sun May 27, 2018 10:43 pm
- Forum: Ionic & Covalent Bonds
- Topic: Polar Vs. Non-Polar
- Replies: 7
- Views: 1364
Re: Polar Vs. Non-Polar
Do they provide us with electronegative values to figure out whether it is polar covalent, non-polar covalent, or ionic? They generally won't. You usually just use the electronegativity trends of the periodic table to determine the type of bonds. At least that's what most practice problems I've don...
- Sun May 27, 2018 10:41 pm
- Forum: Electronegativity
- Topic: In Class Example Between LiF and CsF
- Replies: 2
- Views: 752
Re: In Class Example Between LiF and CsF
I mean by the logic of determining whether a bond is ionic, it's the difference between the electronegativities. If the difference is greater than 2.0 it should be more ionic. At least that was my understanding. so CsF should be more ionic.
- Sun May 27, 2018 10:32 pm
- Forum: Sigma & Pi Bonds
- Topic: Logic behind Sigma and Pi bonds?
- Replies: 2
- Views: 521
Re: Logic behind Sigma and Pi bonds?
Also keep in mind that sigma bonds allow rotation in a molecule while pi bonds do not. It may help to draw examples of this in order to visualize it.
- Sun May 27, 2018 10:26 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: shape of water
- Replies: 8
- Views: 1197
Re: shape of water
Keep in mind you do not need to know the bond angle for this shape because it varies from molecule to molecule. 106 degrees is not the standard bent shape angle.
- Sun May 27, 2018 10:19 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angle
- Replies: 10
- Views: 1160
Re: Bond Angle
Generally lone pairs on the central atom will cause a decrease in bond angle due to the lone pair trying to repel the bonded pair of electrons.
- Sun May 13, 2018 7:06 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 3.5 b) [ENDORSED]
- Replies: 5
- Views: 752
Re: 3.5 b) [ENDORSED]
It may be easier for you to just count across the periodic table. That way you won't forget to put the the configuration in increasing order. Just out of curiosity, how are you solving it because it is kinda odd to get it all out of order and then put it in order.
- Sun May 13, 2018 7:02 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Midterm Question
- Replies: 13
- Views: 1422
Re: Midterm Question
the easiest way to do this problem was to either know how many orbitals each subshell has or to apply the formula 2(l)+1 where if l=0 or the s subshell then, there are 2(0)+1 orbitals or 3 orbitals. This formula makes is very easy to find the orbitals. Or just count the ml numbers or count on the pe...
- Sun May 13, 2018 6:26 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: d block electron configuration
- Replies: 5
- Views: 1356
Re: d block electron configuration
Cations in the d-block lose their electrons in the s-orbital because generally transition metals in the d block will try to either maintain a half or full state as it is more stable. As a result, it is easier to lose the electrons in the 4s orbital first than the d-block because it allows the elemen...
- Sun May 13, 2018 6:19 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 5a,c ; 19b,e ; 21d
- Replies: 2
- Views: 440
Re: 5a,c ; 19b,e ; 21d
Remember Lavelle told us in class that the d-orbital is filling before the s orbital of its row meaning that it is technically of lower energy. Meaning, that electrons will be taken away from the s orbital before the d orbital.
- Sun May 13, 2018 6:06 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Valence electrons
- Replies: 3
- Views: 574
Re: Valence electrons
Just remember that alot of the elements in the d-block will take an electron from their s orbital to fill the d orbital to make it half way full or all the way full in order to reach a more stable state. That is why Silver has 1 valence electron as it takes an electron from is s orbital to fill its ...
- Sun May 13, 2018 5:54 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 2.51
- Replies: 2
- Views: 385
Re: 2.51
Its the same idea that we use when the d orbital comes into play in the 4s orbital. So yes, the f orbital will fill before the d orbital generally.
- Sun Apr 29, 2018 10:04 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Different d and f orbitals
- Replies: 3
- Views: 469
Re: Different d and f orbitals
you should also know that dz^2 and dx^2y^2 are lobes along the plane while dzx, dyz,and dxy are lobes in-between planes to make it easier to remember how they look in the 3d planes.
- Sun Apr 29, 2018 9:52 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Homework Problem 2.55
- Replies: 5
- Views: 751
Re: Homework Problem 2.55
I think the question is referring to the actual group 5 with transition elements such as V, Nb, Ta, and Db. In that case, the answer should be ns^2 (n-1)d^3. But the answer key says that ns^2 (n-1)d^5. Either the answer key is incorrect, or the question is actually referring to group 5 starting fro...
- Sun Apr 29, 2018 9:40 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: n, l, ml (relates to 2.19)
- Replies: 2
- Views: 342
Re: n, l, ml (relates to 2.19)
They are also related because each quantum number is related to each other through the equation for determining each level. For example, lets look at the l quantum number. if l=2, then we know n=3 because l=0,1,..n-1, meaning that n-1=2 meaning that n=3. This type of relationship is how mathematical...
- Sun Apr 29, 2018 9:24 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 2.27 [ENDORSED]
- Replies: 4
- Views: 615
Re: 2.27 [ENDORSED]
Orbitals and subshell are not the same thing. It is asking you to find the number of orbitals within the subshell. So lets look at (a). it gives you n= 5 and l=2. If n=5 you know it is on the 5th energy level and l=2 means that is it on the d-block hence 5d is the subshell notation. We know l=2 corr...
- Sun Apr 29, 2018 9:01 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 2.25
- Replies: 3
- Views: 386
Re: 2.25
The way I think about it is that if you look at the periodic table and lets use the p-block for the sake of this example. If you count starting at Boron all the way to Neon, then you count six elements in that row of the p-block meaning that their are 6 electrons possible in each p-block row. From t...
- Sun Apr 15, 2018 5:29 pm
- Forum: Properties of Light
- Topic: Threshold Energy [ENDORSED]
- Replies: 3
- Views: 267
Re: Threshold Energy [ENDORSED]
It really just depends on what is given to you in the problem. Some problems will give you the threshold energy. Some will not and in these types of problems, you will have to solve them. Meaning using the equation Lavelle gave to us in class, Energy of the photon- threshold energy= kinetic energy o...
- Sun Apr 15, 2018 5:26 pm
- Forum: Empirical & Molecular Formulas
- Topic: Combustion Reaction [ENDORSED]
- Replies: 6
- Views: 664
Re: Combustion Reaction [ENDORSED]
I meant can you use a combustion reaction to find the empirical formula of a compound that does not contain oxygen? Or will oxygen always be present in the final empirical formula? Well yes, there are some compounds that react with Oxygen that they themselves do not contain oxygen within. Combustio...
- Sun Apr 15, 2018 5:19 pm
- Forum: Properties of Light
- Topic: Units for wavelengths [ENDORSED]
- Replies: 6
- Views: 662
Re: Units for wavelengths [ENDORSED]
I mean from the way Lavelle made it out to be in class, he just said that we use nanometers just to make it easier to say but it truly doesn't make a difference whether you use meters or nanometers would be my guess unless they specify in the problem to use one or the other.
- Sun Apr 15, 2018 5:16 pm
- Forum: Properties of Light
- Topic: HW 1.7 (using nm vs pm)
- Replies: 8
- Views: 762
Re: HW 1.7 (using nm vs pm)
Adding on to that, unless the specify what type of unit they want you to use, I am pretty sure you are free to choose then. Its usually best to stick with the units given in the problem unless told otherwise.
- Sun Apr 15, 2018 5:13 pm
- Forum: Properties of Light
- Topic: Quantized v. Discrete
- Replies: 5
- Views: 514
Re: Quantized v. Discrete
I understand what discrete mean but when he was talking about variables being quantized, Lavelle made it out to be something different. My understanding of quantized is that a variable that is quantized is discrete because the act of quantization makes variables or values discrete. Is this correct o...
- Sun Apr 15, 2018 4:56 pm
- Forum: Properties of Light
- Topic: HW chapter 1 question 3
- Replies: 5
- Views: 586
Re: HW chapter 1 question 3
C is correct because the change in an electric field is depends on the frequency of electromagnetic radiation. As a result, if the electromagnetic radiation has a low frequency, then it will create a small area of electric field and if the electromagnetic radiation has a high frequency, then it will...
- Sun Apr 15, 2018 4:50 pm
- Forum: Properties of Light
- Topic: HW ch1 question 5
- Replies: 3
- Views: 353
Re: HW ch1 question 5
So energy of radiation for the photons increases with an increase in its frequency, meaning the photons with higher frequencies will have higher energy of radiations.