Search found 33 matches
- Wed Jun 13, 2018 11:47 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: strong acids
- Replies: 4
- Views: 769
Re: strong acids
Strong acids will release all of their hydrogens in water, therefore they will dissolve.
- Wed Jun 13, 2018 3:08 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Happy Lavelle [ENDORSED]
- Replies: 5
- Views: 1228
Happy Lavelle [ENDORSED]
Lavelle is always so happy to teach :,)
- Mon Jun 11, 2018 8:59 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acids and bases
- Replies: 3
- Views: 603
Re: Acids and bases
Bond strength & Bond polarity: -the smaller the atom the stronger the bond strength -When going down a row in the Periodic Table, the atoms get larger so the strength of the bonds get weaker, which means the acids get stronger. Is this true for every row in the periodic table? Also, this was re...
- Mon Jun 11, 2018 8:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angle [ENDORSED]
- Replies: 4
- Views: 776
Re: Bond Angle [ENDORSED]
In the notes he gave us the number of degrees for each type of angle/vsepr model. You should review the notes and try to memorize them!!
- Mon Jun 11, 2018 8:53 pm
- Forum: Sigma & Pi Bonds
- Topic: strength of bonds
- Replies: 3
- Views: 505
Re: strength of bonds
A sigma bond remains unchanged upon rotation and so can rotate freely, but to rotate a pi bond you must break the chemical bond, rotate and reform. Bond breaking requires energy, and at room temperature the molecules do not have sufficient thermal energy to overcome the energy barrier. It is possibl...
- Mon Jun 11, 2018 8:49 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: final [ENDORSED]
- Replies: 4
- Views: 883
Re: final [ENDORSED]
Molecular orbital (MO) theory is a method for determining molecular structure in which electrons are not assigned to individual bonds between atoms, but are treated as moving under the influence of the nuclei in the whole molecule.
- Mon Jun 11, 2018 8:45 pm
- Forum: Bond Lengths & Energies
- Topic: antibond? [ENDORSED]
- Replies: 2
- Views: 572
Re: antibond? [ENDORSED]
An antibonding orbital is a type of molecular orbital (MO) that weakens the bond between two atoms and helps to raise the energy of the molecule relative to the separated atoms. Such an orbital has one or more nodes in the bonding region between the nuclei.
- Mon Jun 11, 2018 8:44 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Review Sessions Finals Week - Hedrick Hall? [ENDORSED]
- Replies: 6
- Views: 1048
Re: Review Sessions Finals Week - Hedrick Hall? [ENDORSED]
There is a big review session tomorrow (Tuesday) in Dodd 147 at 11am that you can also consider attending.
- Mon Jun 11, 2018 8:42 pm
- Forum: Ionic & Covalent Bonds
- Topic: ionic character
- Replies: 11
- Views: 2149
Re: ionic character
Br has a stronger ionic character than iodine, therefore NaBr is stronger. You can tell apart the stronger ionization by going up and right in the periodic table.
- Sun Jun 03, 2018 10:36 pm
- Forum: Ionic & Covalent Bonds
- Topic: lone pairs
- Replies: 2
- Views: 447
Re: lone pairs
As simple as The lone pairs are localized on the central atom. The lone pairs electrons in a molecule occupy more space as compared to the bonding pairs of electrons. This results in greater repulsion b/w lone pairs of electrons as compared to lone pair-bond pair and bond pair-bond pair repulsion.
- Sun Jun 03, 2018 10:29 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR
- Replies: 7
- Views: 984
Re: VSEPR
This video has a lot of great information!!
https://www.bing.com/videos/search?q=ho ... ORM=VIREHT
https://www.bing.com/videos/search?q=ho ... ORM=VIREHT
- Sun Jun 03, 2018 10:26 pm
- Forum: Hybridization
- Topic: hybridization of an atom
- Replies: 2
- Views: 443
Re: hybridization of an atom
Hybridization is the concept of mixing atomic orbitals into new hybrid orbitals (with different energies, shapes, etc., than the component atomic orbitals) suitable for the pairing of electrons to form chemical bonds in valence bond theory.
- Mon May 28, 2018 3:18 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Drawing
- Replies: 7
- Views: 832
Re: VSEPR Drawing
You should know what the model looks like for you own self knowledge, but it is not required to draw it out during an exam. We only need to draw the 2D shape.
- Mon May 28, 2018 1:15 am
- Forum: Bond Lengths & Energies
- Topic: Energies
- Replies: 4
- Views: 637
Re: Energies
The way you find the strongest or lowest energy is by finding the formal charges!!
Take the formal charge of every element in the molecule.
Take the formal charge of every element in the molecule.
- Mon May 28, 2018 1:07 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSPER MODEL
- Replies: 3
- Views: 1315
Re: VSPER MODEL
I usually find the total number of electrons first and then begin to make a structure that will contain the lowest formal charge. It's usually guess and check for me.
-Guess the structure.
-Check the formal charge.
:)
-Guess the structure.
-Check the formal charge.
:)
- Mon May 21, 2018 10:07 pm
- Forum: Resonance Structures
- Topic: 3.117
- Replies: 2
- Views: 477
3.117
Can someone please help explain parts a) b) c) of this question?
- Sun May 20, 2018 10:02 pm
- Forum: Resonance Structures
- Topic: Stability
- Replies: 3
- Views: 458
Re: Stability
-Structures having filled octet a for second row elements (C, N, O, F) are stable.
-Structures having minimum number of formal charges and maximum number of bonds.
-Structure in which negative charge appears on the most electronegative atom (C < N < O).
Hope this helps a little!!
-Structures having minimum number of formal charges and maximum number of bonds.
-Structure in which negative charge appears on the most electronegative atom (C < N < O).
Hope this helps a little!!
- Sat May 19, 2018 3:05 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Oxidation numbers
- Replies: 4
- Views: 899
Re: Oxidation numbers
To find oxidation numbers... 1) The oxidation number of a free element is always 0. 2) The oxidation number of a monatomic ion equals the charge of the ion. 3) The oxidation number of H is +1, but it is -1 in when combined with less electronegative elements. 4) The oxidation number of O in compounds...
- Sat May 19, 2018 3:02 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Oxidation numbers
- Replies: 4
- Views: 899
Re: Oxidation numbers
Oxidation numbers are numbers you assign to an element in chemical combination that represents the number of electrons lost (or gained, if the number is negative) by an atom of that element in the compound.
- Sat May 19, 2018 3:01 pm
- Forum: Ionic & Covalent Bonds
- Topic: Radicals [ENDORSED]
- Replies: 5
- Views: 765
Re: Radicals [ENDORSED]
A radical is an atom, molecule, or ion that has an unpaired valence electron.
- Sat May 19, 2018 3:00 pm
- Forum: Resonance Structures
- Topic: How does a resonance structure work?
- Replies: 10
- Views: 1159
Re: How does a resonance structure work?
Resonance or mesomerism is a way of describing delocalized electrons within certain molecules or polyatomic ions where the bonding cannot be expressed by one single Lewis structure.
- Sat May 19, 2018 2:59 pm
- Forum: Ionic & Covalent Bonds
- Topic: Octet rule
- Replies: 17
- Views: 2426
Re: Octet rule
The octet rule is a chemical rule of thumb that reflects observation that atoms of main-group elements tend to combine in such a way that each atom has eight electrons in its valence shell, giving it the same electron configuration as a noble gas.
- Thu May 17, 2018 12:10 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: 3.49
- Replies: 3
- Views: 566
Re: 3.49
I'm sure they are asking for the octet due to the fact that this would make the molecule much more stable. What I don't understand is... Do we always have to draw the most stable molecule? Or can we submit a answer that is not in its MOST stable form?
- Mon Apr 23, 2018 11:44 pm
- Forum: Properties of Light
- Topic: Question 1.57
- Replies: 1
- Views: 130
Question 1.57
How do you find the wavelength of the next line in the series?
I keep looking up YouTube videos, but they all use different equations and they skip the explanation. Can someone please go over how to find the next line in details?
-THANK YOU :)
I keep looking up YouTube videos, but they all use different equations and they skip the explanation. Can someone please go over how to find the next line in details?
-THANK YOU :)
- Sun Apr 22, 2018 11:11 pm
- Forum: Photoelectric Effect
- Topic: Application of different formulas [ENDORSED]
- Replies: 4
- Views: 513
Re: Application of different formulas [ENDORSED]
I second this! The most confusing part for me is understanding when it is appropriate to use a certain formula. I am most confused about the all the formulas used in "Quantum". If posting all the formulas is too much, please post the ones used in quantum/ all the useful ones needed for thi...
- Sun Apr 22, 2018 11:06 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Memorizing spectrum
- Replies: 5
- Views: 766
Re: Memorizing spectrum
Will any of these be provided during our quiz or midterm?
- Sun Apr 22, 2018 11:03 pm
- Forum: DeBroglie Equation
- Topic: QM Description of Atoms
- Replies: 2
- Views: 305
Re: QM Description of Atoms
This is because electrons have electrostatic attractions and this can be seen through the line spectra that arises from transitions between discrete (quantized) energy states.
- Sun Apr 15, 2018 9:53 pm
- Forum: SI Units, Unit Conversions
- Topic: Quiz 1
- Replies: 6
- Views: 713
Re: Quiz 1
The empirical formula would be the smallest ratio of the elements. For example if the molecular formula was C4H10, the empirical formula would be C2H5 (divided by a ratio of 2). Whereas the molecular formula tells you how many atoms are in that compound. -This was very helpful!! does this mean we h...
- Sun Apr 15, 2018 9:51 pm
- Forum: SI Units, Unit Conversions
- Topic: chemical formula [ENDORSED]
- Replies: 4
- Views: 955
Re: chemical formula [ENDORSED]
I believe the 2 in 2Na is acting as a coefficient, so you would have 2 mols of Na whereas Na2 would change the structure of the atom. Na2 would be 2 Na bonded together while 2Na is still an unbound Na but in with a stochiometric coefficient so the ratios allow the chemical reaction to be balanced. ...
- Sun Apr 15, 2018 9:35 pm
- Forum: SI Units, Unit Conversions
- Topic: Do we need to memorize unit conversions? [ENDORSED]
- Replies: 9
- Views: 4777
Re: Do we need to memorize unit conversions? [ENDORSED]
Does anyone know any helpful ways to memorize these conversions?
- Sun Apr 15, 2018 9:33 pm
- Forum: SI Units, Unit Conversions
- Topic: chemical formula [ENDORSED]
- Replies: 4
- Views: 955
chemical formula [ENDORSED]
When writing a chemical formula/ equation, what is the difference between the placement of where the number goes? ... example: 2Na and Na2? I was very confused about this during quiz 1.
- Sun Apr 15, 2018 9:25 pm
- Forum: SI Units, Unit Conversions
- Topic: Quiz 1
- Replies: 6
- Views: 713
Quiz 1
I am confused as to how to tell the difference between the empirical formula and the molecular formula... There was a question on the exam that gave multiple molecules and we had to give both the empirical and molecular formula, how do we find them? Someone help :(
- Sun Apr 15, 2018 9:14 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing Chemical Reactions
- Replies: 5
- Views: 476
Re: Balancing Chemical Reactions
I am confused about how to balance an equation that involves fractions... An example is making 2Ca--> 5Ca. How would we go about this? I know you have to use fractions and then turn them into whole numbers, but I am still confused as to how to approach it and fully solve it.