Search found 30 matches
- Sat Dec 08, 2018 8:33 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Calculating pH or pOH with Molarity
- Replies: 3
- Views: 494
Re: Calculating pH or pOH with Molarity
Dr. Lavelle might give us a multistep question to involves both fundamentals as well as acids and bases. So he might first ask for us to calculate the molarity of a solution by only giving us the amount of substance and the total volume of the solution, and then ask us to find the pH of the solution.
- Sat Dec 08, 2018 12:56 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Strength of Acids vs. Number of Oxygens
- Replies: 6
- Views: 1446
Strength of Acids vs. Number of Oxygens
Why does the strength of an acid increase with the oxidation number of the central atom and the number of oxygens bonded to the central atom?
- Fri Dec 07, 2018 5:54 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Myoglobin coordination compound
- Replies: 1
- Views: 270
Myoglobin coordination compound
Why can myoglobin only bind to one O2 molecule when iron ions can bind up to 2 ligands after being bonded with the HEME Complex. The HEME complex in myoglobin has 4 binding locations so shouldn’t iron be able to take 2 O2 molecules instead of 1?
Re: Ligands
A Ligand is a polydentate if it has two or more atoms that have lone pairs and can therefore bind to a metal ion. I found this website to be extremely helpful in defining the various types of ligands :
https://www.chemicool.com/definition/ligand.html
https://www.chemicool.com/definition/ligand.html
- Sun Dec 02, 2018 1:27 pm
- Forum: Naming
- Topic: H20 monodentate
- Replies: 1
- Views: 258
Re: H20 monodentate
Polydentates refers to the number of atoms capable of bonding to a central metal ion. Although H2O has two lone pairs, they are both on the Oxygen atom, thus making the molecule a monodentate.
- Sun Dec 02, 2018 1:19 pm
- Forum: Lewis Acids & Bases
- Topic: Weak Acid/Base vs. Strong
- Replies: 7
- Views: 850
Weak Acid/Base vs. Strong
What is the best way to differentiate between a strong acid/base and a weak acid/base. For example how do we know ammonia is a weak base while sodium hydroxide is a strong base and acetic acid is a weak acid while HCl is a strong acid.
- Sun Nov 25, 2018 5:15 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Hw: Ch.4 #73 (6th Edition)
- Replies: 2
- Views: 360
Re: Hw: Ch.4 #73 (6th Edition)
CH2^2- has a Lewis structure similar to H2O, where the central atom (C) is bonded to two hydrogen atoms and has two unpaired electron pairs. This corresponds to a VESPR Formula of AX2E2 which has a bond angle of 104.5. The lone pairs are not directly opposite of each other but are at an angle of 104...
- Sat Nov 24, 2018 11:03 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 3
- Replies: 10
- Views: 1107
Re: Test 3
I think test 3 will cover all the information in the Molecular Shape and Structure Outline along with the rest of chapter 3 from 3.12 onward, so Ionic bonds vs. Covalent bonds, and Bond shape and bond strength.
- Sat Nov 24, 2018 10:58 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR model formula
- Replies: 3
- Views: 325
Re: VSEPR model formula
The VSEPR model formula is a representation of the 3D structure of the molecule. The A in the formula represents the central atom, the X represents the number of bonding pairs, and the E represents the number of unpaired electron pairs. For example SF4 would have a VSEPR formula of AX4E because the ...
- Sun Nov 18, 2018 5:37 pm
- Forum: Hybridization
- Topic: Sigma and Pi Bonds [ENDORSED]
- Replies: 12
- Views: 1033
Re: Sigma and Pi Bonds [ENDORSED]
Does anyone know the reason why pi bonds cannot rotate while sigma bonds can, so like how does the structure of each bond result in their ability to rotate?
- Sun Nov 18, 2018 5:29 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge of Central Atom
- Replies: 4
- Views: 1162
Re: Formal Charge of Central Atom
The formal charge of the Cl atom in ClO2+ can be +1 because the net charge of the all of the atoms should equal the net charge of the polyatomic ion which is +1 in this case. If both of the Cl-O bonds are double bonds then the two oxygen atoms have a formal charge of zero, and the formal charge of t...
- Sat Nov 17, 2018 11:19 pm
- Forum: Ionic & Covalent Bonds
- Topic: Determining the Difference between Ionic and Covalent Bonds
- Replies: 6
- Views: 663
Re: Determining the Difference between Ionic and Covalent Bonds
When determining the difference between an ionic bond and a covalent bond, you first should look at the various elements in the molecule/compound in question. A molecule (covalent bonds) usually is between two nonmetals while a compound(ionic bonds) is usually between a metal and a nonmetal. However...
- Sun Nov 11, 2018 9:19 pm
- Forum: Bond Lengths & Energies
- Topic: Hydrogen Bonds
- Replies: 1
- Views: 277
Hydrogen Bonds
Why do different types of Hydrogen bonds have different bond energies. For example, why does a hydrogen bond between hydrogen and fluorine have a higher bond energy than a hydrogen bond between hydrogen and nitrogen. (F-----H—F) vs. (N-----H—N)
- Sun Nov 11, 2018 9:11 pm
- Forum: Lewis Structures
- Topic: VSEPR Model
- Replies: 1
- Views: 285
Re: VSEPR Model
The geometry of molecules is formatted so that the electrons within the molecule have the least amount of repulsion possible. Repulsion strength is determined by looking at state of the electrons. Electrons that are lone pairs have the most repulsion so two lone pairs should be drawn on opposite sid...
- Sun Nov 11, 2018 9:00 pm
- Forum: Resonance Structures
- Topic: Bond lengths
- Replies: 1
- Views: 312
Re: Bond lengths
It depends on the possible resonance structures and the proportions of single bonds to double bonds. For example if there is one single bond and one double bond in a molecule, such as NO2-, the bond length would be around the average of the two. ((130nm(double bond) +150nm(single bond))/2) = 140nm. ...
- Sat Nov 03, 2018 10:42 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Determining Amount of Electrons From Quantum Numbers
- Replies: 4
- Views: 5698
Re: Determining Amount of Electrons From Quantum Numbers
The principal quantum number n determines the shell where the electrons are located, and the angular momentum quantum number l describes the shape (s, p, d, f). l can be any value from 0 to n-1. Therefore if we are asked how many electrons are in n=3 and l=2, we first try and determine which subshel...
- Sat Nov 03, 2018 10:33 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic Radius
- Replies: 6
- Views: 1005
Re: Atomic Radius
Atomic radius increases across a period because the additional electrons being added are all in the same shell while at the same time we are adding protons to the nucleus. As we add more protons to the nucleus, the effective nuclear charge pulls the electron closer towards the nucleus. However, each...
- Sat Nov 03, 2018 10:25 pm
- Forum: Properties of Light
- Topic: Practice Midterm 8b
- Replies: 3
- Views: 563
Re: Practice Midterm 8b
In the midterm review today, Lyndon used the work function equation : E(photon) - Threshold energy = E(kinetic energy) E(photon) = Plank constant(h)*frequency(v), threshold energy/work function is given, and E(kinetic energy) = 1/2(MV^2) where M is the mass of the electron and V is the velocity of t...
- Sun Oct 28, 2018 6:38 pm
- Forum: Student Social/Study Group
- Topic: Studying for tests/midterm
- Replies: 18
- Views: 2666
Re: Studying for tests/midterm
Do you guys know when/where these peer learning sessions usually are? Is there a schedule for them?
- Sun Oct 28, 2018 6:34 pm
- Forum: Ionic & Covalent Bonds
- Topic: Polyatomic Ions [ENDORSED]
- Replies: 4
- Views: 501
Polyatomic Ions [ENDORSED]
Do we need to memorize the chemical formulas for common polyatomic ions such as Ammonium, Carbonate, Nitrate etc. or will their chemical formulas be given to us whenever they come up on a quiz or test.
- Sun Oct 28, 2018 6:28 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2998735
Re: Post All Chemistry Jokes Here
A covalent bond yells at an ionic bond, "Didn't anybody ever teach you how to share?"
- Sun Oct 21, 2018 9:17 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Hw Question 2.25
- Replies: 1
- Views: 312
Re: Hw Question 2.25
a. Since its in the p orbital, there are 6 electrons
b. since its in the d orbital, there are 10 electrons
c. Since its in the s orbital, there are 2 electrons
d. Since its in the f orbitals, there are 14 electrons
b. since its in the d orbital, there are 10 electrons
c. Since its in the s orbital, there are 2 electrons
d. Since its in the f orbitals, there are 14 electrons
- Sun Oct 21, 2018 7:59 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Px. Py, Pz
- Replies: 6
- Views: 1660
Re: Px. Py, Pz
The Px, Py, Pz variables represent the 3 different electron cloud configurations in the p orbital of an atom. In relation Schrodinger's Wave Function, they are determined by the Ml value which range from -1 to 1. A -1 Ml value equals Px, 0 equals to Py, and 1 equals to Pz. i.e. the example Dr. Lavel...
- Sun Oct 21, 2018 7:40 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Electron Shielding
- Replies: 2
- Views: 542
Electron Shielding
Can someone explain to me what electron shielding is and why electrons further away from the nucleus is less attractive.
- Sun Oct 14, 2018 12:52 pm
- Forum: Einstein Equation
- Topic: Test #2
- Replies: 4
- Views: 419
Re: Test #2
The Test Schedule on the website says Test #2 will be given starting October 23, which are the discussions of week 4.
- Sun Oct 14, 2018 12:47 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Friday Lecture Example Question
- Replies: 1
- Views: 188
Friday Lecture Example Question
For the first example we did in class on Friday, why did we plug in a positive value into v= (E/h) when the calculated change in energy was a negative value.
- Sun Oct 14, 2018 12:42 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: n Quantum Number
- Replies: 1
- Views: 146
Re: n Quantum Number
Because the n in the empirical equation for energy in hydrogen atoms (E =-hR/n^2) is in the denominator and is squared, the change in energy between each subsequent energy level decreases at an exponential rate.. Although the actual difference between each energy level gets closer and closer to zero...
- Sun Oct 07, 2018 9:32 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Number of questions on test one [ENDORSED]
- Replies: 39
- Views: 21482
Re: Number of questions on test one [ENDORSED]
Is the test format multiple choice, free response or a mixture of both?
- Sun Oct 07, 2018 9:18 pm
- Forum: Empirical & Molecular Formulas
- Topic: Chemical Formula Element Order
- Replies: 5
- Views: 638
Re: Chemical Formula Element Order
I think the general consensus is that the atoms with lower electronegativity values are written first. So Osmium has the lowest electronegativity of 2.0, compared to Carbon (2.6) and Oxygen(3.4) so it would make sense to write it first. However, I don't think the order of elements in a chemical form...
- Sun Oct 07, 2018 9:03 pm
- Forum: Significant Figures
- Topic: Sig Figs in the Middle of a Problem
- Replies: 9
- Views: 2431
Sig Figs in the Middle of a Problem
Does anyone know if we should follow sig fig rules in the middle of a problem or only round to the nearest significant digit once you get the final answer.