Search found 50 matches
- Fri Dec 06, 2019 12:21 am
- Forum: Naming
- Topic: Double A in Pentaammine?
- Replies: 1
- Views: 187
Re: Double A in Pentaammine?
There are 2 a's, pentaammine.
- Fri Dec 06, 2019 12:19 am
- Forum: Bronsted Acids & Bases
- Topic: Acidic Strength
- Replies: 3
- Views: 268
Re: Acidic Strength
HClO2 is a stronger acid than HBrO2 because Cl is more electronegative (EN: 3.0) than Br (EN: 2.8).
- Fri Dec 06, 2019 12:15 am
- Forum: Hybridization
- Topic: hybridization
- Replies: 1
- Views: 197
Re: hybridization
It would be sp3. It does not matter whether it is an actual bond or a lone pair as long as there is a site of electron density present.
- Fri Dec 06, 2019 12:13 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: what is a ligand?
- Replies: 7
- Views: 507
Re: what is a ligand?
A ligand is a lewis base that donates a pair of electrons to the transition metal it is attached to.
Re: 9c.3d
Oxalate is polydentate (Bidentate) so that is the reason it has the prefix "bis-" in front of it. The "bis" prefix suggests that there are 2 oxalate ligands that are attached to the transition metal, which explains why the answer is Na[Fe(OH2)2(C2O4)2].
- Fri Nov 29, 2019 9:49 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: coordination number
- Replies: 8
- Views: 412
Re: coordination number
Coordination number corresponds to the number of electron density regions that are connected to the transition metal. There tends to be a max of 6.
- Fri Nov 29, 2019 9:43 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligands
- Replies: 6
- Views: 421
Re: Ligands
Yes. The ligands donate an electron pair.
- Fri Nov 29, 2019 9:42 pm
- Forum: Bond Lengths & Energies
- Topic: Melting Points
- Replies: 8
- Views: 739
Re: Melting Points
Yes, you are correct. The stronger the IMF = more force needed to break the bond (i.e higher melting point).
- Fri Nov 29, 2019 9:41 pm
- Forum: Conjugate Acids & Bases
- Topic: NH3, acid or base?
- Replies: 12
- Views: 8076
Re: NH3, acid or base?
Ammonia is a base because the lone pair on the nitrogen gets donated to other acids that are in need of an electron pair.
- Fri Nov 29, 2019 9:38 pm
- Forum: Hybridization
- Topic: Hybridization for elements like S, Xe, Br, etc.
- Replies: 4
- Views: 353
Re: Hybridization for elements like S, Xe, Br, etc.
Hybridization works the same for all elements.
- Thu Nov 21, 2019 11:00 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Problem 3F10 b
- Replies: 6
- Views: 417
Re: Problem 3F10 b
Si2F2
- Thu Nov 21, 2019 10:57 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Bond Angles for Shapes with Lone Pairs
- Replies: 5
- Views: 355
Re: VSEPR Bond Angles for Shapes with Lone Pairs
Yes the bond angles are all correct.
- Thu Nov 21, 2019 10:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Week 8 homework
- Replies: 2
- Views: 221
Re: Week 8 homework
I think we can still turn in homework on molecular structures because we discussed molecular structures (hybridization) on Monday.
- Thu Nov 21, 2019 10:48 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: NH3 replaces H20 ligands
- Replies: 2
- Views: 191
Re: NH3 replaces H20 ligands
Great question. I would also like to know why so I am commenting so I can locate this post easily.
- Thu Nov 21, 2019 10:47 pm
- Forum: Hybridization
- Topic: HW 2F.5.
- Replies: 3
- Views: 287
Re: HW 2F.5.
In order to find hybridization, you have to count the number of regions of electron density around the central atom. It can be useful to draw out the lewis structure to see the regions of e- density. After that, you would simply write out the hybridization: s- 1 region of electron density sp- 2 regi...
- Thu Nov 14, 2019 11:58 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: bond angles
- Replies: 9
- Views: 568
Re: bond angles
Some angles have "less than" because they have lone pairs, which distort the pull that the atoms have on each other.
- Thu Nov 14, 2019 11:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lewis Structures & VSEPR
- Replies: 9
- Views: 437
Re: Lewis Structures & VSEPR
Definitely not necessary. However, it can help you know how many lone pairs and bonded pairs there are, which is essential for VSEPR.
- Thu Nov 14, 2019 11:55 pm
- Forum: Electronegativity
- Topic: Increasing/Decreasing Electronegativity
- Replies: 14
- Views: 2656
Re: Increasing/Decreasing Electronegativity
Electronegativity is the ability of an atom to pull on other atoms. The trend that electronegativity follows is that it increases to the right and up on the periodic table.
- Thu Nov 14, 2019 11:45 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.3
- Replies: 3
- Views: 217
Re: 2E.3
The lewis structure would have 4 bonded pairs. So, the C would have a bond pair with 2 Fs and 2 Hs. Since there are 4 bonded pairs and no lone pairs, the shape of the molecule is a tetrahedral.
- Thu Nov 14, 2019 11:42 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: structure ?
- Replies: 8
- Views: 411
Re: structure ?
Linear molecular shapes arise when there are 2 bonded pairs. If there are zero, three, or four lone pairs attached to the central atom that already has two bonded pairs, the molecule would have a linear shape.
- Thu Nov 07, 2019 6:59 pm
- Forum: Ionic & Covalent Bonds
- Topic: Polarizability
- Replies: 6
- Views: 418
Re: Polarizability
Polarizability increases as the charge and the size of the anion increases.
- Thu Nov 07, 2019 6:57 pm
- Forum: Ionic & Covalent Bonds
- Topic: Bond Strength
- Replies: 12
- Views: 1035
Re: Bond Strength
Ionic bonds are stronger than covalent bonds in a vacuum. However, in water, covalent bonds tend to be stronger.
- Thu Nov 07, 2019 6:49 pm
- Forum: Bond Lengths & Energies
- Topic: dissociation energy
- Replies: 5
- Views: 348
Re: dissociation energy
The trend for dissociation energy is that as bond length increases, the dissociation energy decreases.
- Thu Nov 07, 2019 6:46 pm
- Forum: Lewis Structures
- Topic: Exceptions for the octet rule
- Replies: 5
- Views: 363
Re: Exceptions for the octet rule
Sulfur is also an exception to the octet rule. I believe it can go up to 12 electrons as it does in SF6.
- Thu Nov 07, 2019 6:43 pm
- Forum: General Science Questions
- Topic: Week 6 homework problems
- Replies: 7
- Views: 501
Re: Week 6 homework problems
The homework questions should consist of chemical bonds. Personally, I included 2D material and on.
- Thu Oct 31, 2019 7:33 pm
- Forum: Resonance Structures
- Topic: Resonance
- Replies: 5
- Views: 179
Re: Resonance
Yes. Resonant structures are just different ways of drawing the same structure. These structures should still follow the octet rule when being drawn all of these different ways.
- Thu Oct 31, 2019 7:29 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Hw problem 2A.13
- Replies: 4
- Views: 161
Re: Hw problem 2A.13
Make sure to remove the electrons from the highest energy orbital. For example Zn: [Ar] 3d^10 4s^2, the electrons would be removed from the 4s orbital since it is the highest energy orbital.
- Thu Oct 31, 2019 7:25 pm
- Forum: Octet Exceptions
- Topic: Radicals: Homework Problem #2C1
- Replies: 8
- Views: 421
Re: Radicals: Homework Problem #2C1
NO2- is not a radical. It has 18 electrons, all of which are paired.
- Thu Oct 31, 2019 7:23 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 11
- Views: 559
Re: Electronegativity
Electronegativity is the tendency of an atom to pull electrons. Electronegativity follows the same trends as ionization energy (Increases up and to the right).
- Thu Oct 31, 2019 7:18 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm
- Replies: 16
- Views: 670
Re: Midterm
Everything we have been assigned homework on until 2D. In other words, Fundamentals, Quantum World, & Chemical Bonds (up to 2D).
- Thu Oct 24, 2019 6:31 pm
- Forum: Ionic & Covalent Bonds
- Topic: Does the Octet Rule apply to Boron?
- Replies: 14
- Views: 795
Re: Does the Octet Rule apply to Boron?
No, the Octet rule does not apply to Boron bc it is more stable with 6 e-.
- Thu Oct 24, 2019 6:27 pm
- Forum: Octet Exceptions
- Topic: Octet exception examples
- Replies: 9
- Views: 263
Re: Octet exception examples
During Wednesday's lecture, he mentioned H, He, Li, and Be as being exceptions to the octet rule because it was very unlikely that they would gain the electrons needed to complete an octet.
- Thu Oct 24, 2019 6:20 pm
- Forum: Ionic & Covalent Bonds
- Topic: valence electrons
- Replies: 6
- Views: 432
Re: valence electrons
Sb has the electron configuration [Kr] 4d^10 5s^2 5p^3.
Since the 4th shell is completely filled, we only focus on the electrons from the fifth shell. With that being said, we only have 5 valence electrons in the 5th shell (2 e- from s-shell & 3 e- from p-shell).
Since the 4th shell is completely filled, we only focus on the electrons from the fifth shell. With that being said, we only have 5 valence electrons in the 5th shell (2 e- from s-shell & 3 e- from p-shell).
- Thu Oct 24, 2019 6:14 pm
- Forum: Properties of Electrons
- Topic: hw
- Replies: 6
- Views: 343
Re: hw
Since we covered both quantum and chemical bonds this week, it is fine to turn in hw that includes Quantum.
- Tue Oct 22, 2019 10:38 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Question 1E.7
- Replies: 1
- Views: 91
Question 1E.7
Can someone explain to me as to why 1E.7 letter B is not considered the ground state electron configuration for N. Thank you. :)
- Thu Oct 17, 2019 10:17 pm
- Forum: *Shrodinger Equation
- Topic: Nodal Planes
- Replies: 6
- Views: 335
- Thu Oct 17, 2019 10:15 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Tutoring? [ENDORSED]
- Replies: 121
- Views: 240623
Re: Tutoring? [ENDORSED]
If you're eligible, I would suggest joining AAP and attending the peer learning sessions. Really helpful!
- Thu Oct 17, 2019 10:14 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg constant
- Replies: 3
- Views: 136
Re: Rydberg constant
Yes, the Rydberg constant is specific to H atoms.
- Thu Oct 17, 2019 10:11 pm
- Forum: Photoelectric Effect
- Topic: HW 1B.5
- Replies: 8
- Views: 336
Re: HW 1B.5
Yes. You have to convert keV to J before starting the problem.
- Thu Oct 17, 2019 12:01 am
- Forum: Quantum Numbers and The H-Atom
- Topic: QUESTION 1D.23 FROM HW [ENDORSED]
- Replies: 2
- Views: 149
QUESTION 1D.23 FROM HW [ENDORSED]
"How many orbitals can have the following quantum numbers in an atom:(a)n=2,l=1;(b)n=4,l=2,ml=-2; (c)n=2;(d)n=3,l=2,ml=+1?"
Can someone help me with this question? Thank you.
Can someone help me with this question? Thank you.
- Thu Oct 10, 2019 7:49 pm
- Forum: Properties of Light
- Topic: Waves/Particles
- Replies: 14
- Views: 504
Re: Waves/Particles
From my understanding, photons show wave-particle duality, meaning that they exhibit properties of being a particle and a wave (frequency, amplitude, wavelength, etc).
- Thu Oct 10, 2019 7:46 pm
- Forum: Significant Figures
- Topic: Sig Figs on Tests
- Replies: 24
- Views: 2116
Re: Sig Figs on Tests
Here are the rules for sig figs: 1. Non zero digits are significant. 2. Zeros in between other digits are significant. 3. Leading zeros are NOT significant. 4. Trailing decimal zeros are significant. 5. When adding/subtracting, use the fewest number of decimal places. 6. When multiplying/dividing, u...
- Thu Oct 10, 2019 7:43 pm
- Forum: Empirical & Molecular Formulas
- Topic: Mass Percent Calculations
- Replies: 4
- Views: 190
Re: Mass Percent Calculations
First, you would need to calculate the molar mass of C7H15NO3. After that, you have to find the molar masses of each element of that molecule. One needs to divide the molar masses of each element by the total molar mass of C7H15NO3 and multiply by 100% to find the mass percentage compositions.
- Thu Oct 10, 2019 7:40 pm
- Forum: Student Social/Study Group
- Topic: Pen or Pencil for Homework Problems?
- Replies: 8
- Views: 435
Re: Pen or Pencil for Homework Problems?
I did not read anything regarding us having to use a pen or pencil on hw problems. However, remember to use a pen when it comes to the exams! :)
- Thu Oct 10, 2019 7:38 pm
- Forum: Limiting Reactant Calculations
- Topic: Test 1 Calculator
- Replies: 6
- Views: 371
Re: Test 1 Calculator
A lot of graphing calculators these days are programmable and could contain features that may give others an unfair advantage when it comes to the test. By using a scientific calculator, it ensures that every one has an equal chance.
- Thu Oct 03, 2019 5:04 pm
- Forum: Balancing Chemical Reactions
- Topic: Question L.35 [ENDORSED]
- Replies: 6
- Views: 470
Re: Question L.35 [ENDORSED]
Does anyone know how to finish this problem after balancing the equations? Thank you!
- Wed Oct 02, 2019 10:39 pm
- Forum: Empirical & Molecular Formulas
- Topic: QUESTION F.21 HW
- Replies: 3
- Views: 208
QUESTION F.21 HW
Can someone help me with this question? I've tried it multiple times and can't seem to get the right answer. Thanks in advance!
- Wed Oct 02, 2019 4:51 pm
- Forum: Empirical & Molecular Formulas
- Topic: QUESTION F3
- Replies: 3
- Views: 285
QUESTION F3
Question F3 part A asks "(a) Write the formula for nitric acid." Is this a formula that we are already supposed to know? If not, how does one know the formula without actually calculating the empirical/molecular formulas?
- Tue Oct 01, 2019 9:20 pm
- Forum: SI Units, Unit Conversions
- Topic: Calculator Question
- Replies: 13
- Views: 705
Re: Calculator Question
The scientific calculators that you are able to use in this class must not be able to graph or be able to be programmed. I paid $15 for mine, so I assume that anywhere from $10-$15 is a reasonable price for a calculator.
- Tue Oct 01, 2019 9:16 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Avogadro's Number [ENDORSED]
- Replies: 12
- Views: 782
Re: Avogadro's Number [ENDORSED]
Avogadro's number is 6.0221 x 10^23. It is used to find the number of atoms, molecules, or ions in a mole of any substance.