Search found 31 matches
- Sun Jun 10, 2018 11:26 pm
- Forum: Conjugate Acids & Bases
- Topic: Conjugate Acids/Bases
- Replies: 8
- Views: 1179
Re: Conjugate Acids/Bases
What I heard was that a conjugate acid is when a proton is added (H+) and the conjugate base is when the proton is taken away (H+). for example: HCl + H2O--->H3O(+) + Cl(-) - the HCl is the acid and Cl is the conjugate base since the H was taken away - H2O is the base and the H3O is the conjugate ac...
- Wed Jun 06, 2018 9:08 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shapes On the Final
- Replies: 3
- Views: 399
Re: Molecular Shapes On the Final
I think that we might be asked about the hybridization of the molecular shapes since we went over them in lecture. I attached a picture of the notes i took which can be helpful.
- Wed Jun 06, 2018 8:25 pm
- Forum: Lewis Structures
- Topic: Lowest energy lewis structure
- Replies: 5
- Views: 6969
Lowest energy lewis structure
Can someone explain how to determine the lowest energy Lewis structure of a molecule and maybe provide an example.
- Wed Jun 06, 2018 8:08 pm
- Forum: Lewis Structures
- Topic: Drawing Lewis Structures on the Final Exam
- Replies: 5
- Views: 619
Re: Drawing Lewis Structures on the Final Exam
I remember hearing that you don't have to be exactly accurate when drawing them since it can get tricky, but you should know what the angles are for the shapes in the VSEPR structure if you are asked for them. For example for AX3 its trigonal planar and has bond angles of 120.
- Sun Jun 03, 2018 2:37 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Tetrahedral and Square planar
- Replies: 8
- Views: 1408
Re: Tetrahedral and Square planar
Also I have in my notes that a tetrahedral has bond angles of about 109.5 degrees and square planar 90 degree bond angles.
- Sun Jun 03, 2018 2:15 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond angles [ENDORSED]
- Replies: 3
- Views: 487
Re: Bond angles [ENDORSED]
I find that by knowing the strengths of repulsions (Lone pair & lone pair > Lone pair & bonding pair > bonding pair & bonding pair) is helpful to understand that there will be more repulsion if there are lone pairs therefore causing the angles to become smaller around.
- Sun Jun 03, 2018 2:04 pm
- Forum: Hybridization
- Topic: Hybridization
- Replies: 3
- Views: 463
Hybridization
I am having trouble with this topic. Can someone explain what hybridization is and how to determine it? Also what does it mean to be unhybridized?
Thank you
Thank you
- Sat May 26, 2018 11:51 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR
- Replies: 3
- Views: 435
VSEPR
Can molecules have the same VSEPR formula and what would that mean for the shape, the name and the electron arrangement? Also, what is an example of this if there is one?
- Sat May 26, 2018 11:38 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Remembering Bond Angles
- Replies: 4
- Views: 605
Re: Remembering Bond Angles
Do we also need to know the name of the bonds and the name of the shape they make?
- Sat May 26, 2018 11:25 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizing power
- Replies: 10
- Views: 8706
Re: Polarizing power
Im having trouble understanding this topic so I was wondering if anyone can explain the difference between polarizing power and polarizability and provide a quick example.
- Sat May 19, 2018 9:21 pm
- Forum: Lewis Structures
- Topic: HW 3.37
- Replies: 2
- Views: 377
Re: HW 3.37
The way that I did this was that I counted the total number of electrons on the whole structure (32 electrons) then I saw which elements were given and then counted the amount of valence electron each element had and multiplied it by the number there was on the structure (3 * 7 for Cl and 1 * 6 for ...
- Sat May 19, 2018 8:53 pm
- Forum: Resonance Structures
- Topic: Resonance Structures
- Replies: 9
- Views: 1111
Re: Resonance Structures
I believe that for resonance structures the formal charge may be different and when choosing which is the better structure you choose the one with the lowest formal charge or closest that adds to zero.
- Sat May 19, 2018 8:29 pm
- Forum: Ionic & Covalent Bonds
- Topic: Radicals [ENDORSED]
- Replies: 5
- Views: 725
Re: Radicals [ENDORSED]
Radicals are atoms with unpaired valence electrons and usually have an odd number of electrons.
- Sun May 13, 2018 5:21 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent Bonds
- Replies: 4
- Views: 666
Re: Covalent Bonds
I think that we choose an atom with the lowest ionization energy as the central atom because those are the atoms that have electrons that are less tight.It makes it easier to add more electrons to the atoms to make it less likely to remove electrons and have more bonds.
- Sun May 13, 2018 4:02 pm
- Forum: Lewis Structures
- Topic: Most Important Lewis Structure
- Replies: 4
- Views: 714
Re: Most Important Lewis Structure
I think that you should also first you would see which would fulfill the octet rule, then see which has the smallest formal charge and then see where there is more electronegativity to make that lewis structure the most important one.
- Sun May 13, 2018 3:50 pm
- Forum: Lewis Structures
- Topic: Lewis Structures
- Replies: 4
- Views: 570
Re: Lewis Structures
I think whats most important is that you have the atom that is the least electronegative in the middle because this way you can just add more atoms to fulfill the octet rule.
- Sun May 06, 2018 2:47 pm
- Forum: Ionic & Covalent Bonds
- Topic: cation vs anion
- Replies: 14
- Views: 3602
Re: cation vs anion
Another way is that Cations have a "t" which is similar to a plus sign so its an easy way to know its a positive charge. And anions are just the opposite. Also when you loose electrons, you have a positive charge and when you gain electrons you have negative charge.
- Sun May 06, 2018 2:00 pm
- Forum: Photoelectric Effect
- Topic: Test #2 Question 7 [ENDORSED]
- Replies: 2
- Views: 431
Test #2 Question 7 [ENDORSED]
Copper is used widely in electrical wiring due to its high electrical conductivity and malleability. The threshold energy or "work function" of the copper atom is 7.52* 10^-19 J. What is the maximum wavelength of light (lowest energy) you need to shine onto the copper metal in vacuum to ej...
- Sun May 06, 2018 12:31 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Switching 3d and 4s
- Replies: 6
- Views: 1234
Re: Switching 3d and 4s
Just to clarify, this means that for any element with an electron configuration that has both s and d orbitals, the d orbital would come before the s and followed by p. But for elements without the d orbital it would be the s orbital first. Correct me if I am wrong. And also s orbitals have higher e...
- Sun Apr 29, 2018 10:38 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: PROBLEM 2.1
- Replies: 4
- Views: 451
Re: PROBLEM 2.1
Also the higher the number (n), the further away the electrons are from the nucleus so those electrons have higher energy compared to electrons closer to the nucleus.
- Sun Apr 29, 2018 10:20 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: PROBLEM 2.21
- Replies: 2
- Views: 253
Re: PROBLEM 2.21
For principal it is just the n value, so you would look at the row number on the periodic table or in this case just the number given. Then for the angular its the l values (0,1,2,3) and they correspond to the s,p,d,f orbitals.
- Sun Apr 29, 2018 10:04 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Difference between a shell, subshell, and orbital
- Replies: 4
- Views: 5605
Re: Difference between a shell, subshell, and orbital
Do the subshells (s, p, d, and f) correspond to the orbital angular momentum quantum numbers ( l =0, 1, 2, 3)? I think that each subshell does correspond to the orbital angular momentum quantum numbers. For example, s would correspond to 0, p to 1 and so on. It's an effective way to know from what ...
- Sat Apr 21, 2018 5:23 pm
- Forum: Limiting Reactant Calculations
- Topic: Question from test 1 [ENDORSED]
- Replies: 4
- Views: 748
Re: Question from test 1 [ENDORSED]
I think that to do the second part you would take the mol you got from part a that allowed you to determine that 02 was the limiting reagent and turn that to grams of H2. Then you would subtract the grams given by the grams you found to get what is left over of the unreacted one. Thats how we did it...
- Sat Apr 21, 2018 5:02 pm
- Forum: Properties of Light
- Topic: still don't uderrsatnd what a photon is [ENDORSED]
- Replies: 20
- Views: 1311
Re: still don't uderrsatnd what a photon is [ENDORSED]
Photons don't have mass but they do have energy and momentum, so they are able to move with the speed of light.
- Sat Apr 21, 2018 4:27 pm
- Forum: Properties of Light
- Topic: test 2
- Replies: 18
- Views: 1579
Re: test 2
Since some questions might be asking our understanding of topics would that be like knowing where equations come from and what they mean? Or what are some examples of the type of questions that can be asked?
- Sun Apr 15, 2018 9:23 pm
- Forum: SI Units, Unit Conversions
- Topic: writing out conversions in one long line vs. steps
- Replies: 16
- Views: 1392
Re: writing out conversions in one long line vs. steps
I usually find doing them in one long line more helpful because you can cancel easier and also if you seem to have made a mistake you can catch it quicker since it is all in one line. Its just quicker and more helpful during timed exams.
- Sun Apr 15, 2018 9:15 pm
- Forum: Empirical & Molecular Formulas
- Topic: Finding Empirical and Molecular Formula [ENDORSED]
- Replies: 6
- Views: 943
Re: Finding Empirical and Molecular Formula [ENDORSED]
If there are 2 lines showing a bond do you have to add 2 to both of the elements? Also should you look at the lines or at the number of elements?
- Sun Apr 15, 2018 9:07 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing Chemical Reactions
- Replies: 5
- Views: 440
Re: Balancing Chemical Reactions
What works for me is to draw a vertical line in the arrow and then on each side write down each of the elements with the number each has. Then I see which one shows up less on one side and more on the other and balance those. Then I see which ones are left to balance and go for what of the products ...
- Sun Apr 15, 2018 8:13 pm
- Forum: Empirical & Molecular Formulas
- Topic: Finding Molecular X
- Replies: 9
- Views: 950
Re: Finding Molecular X
Do you mean when you are just given the name? For example Nitrogen trifluoride so then you have to figure out what that compound is.
- Sat Apr 07, 2018 10:19 pm
- Forum: Empirical & Molecular Formulas
- Topic: Finding the molecular formula [ENDORSED]
- Replies: 5
- Views: 653
Re: Finding the molecular formula [ENDORSED]
To find the molecular formula, you would need the molar mass of the empirical formula and most likely the molar mass of the molecular formula will be given. So all you do is divide the molar mass of the molecular formula by the molar mass of the empirical formula and you will get your answer needed ...
- Sat Apr 07, 2018 9:53 pm
- Forum: General Science Questions
- Topic: Rusty on High School Chem [ENDORSED]
- Replies: 347
- Views: 416112
Re: Rusty on High School Chem [ENDORSED]
Since there is no longer a course reader, where would one suggest to find more practice problems to prepare for the first test? The module questions are helpful, but they are different than both the homework problems and the problems received in discussion section. Hey, there are worksheets that th...