Search found 43 matches

by Christine Chow 4G
Mon Dec 03, 2018 3:51 pm
Forum: Naming
Topic: nitro vs nitrito
Replies: 3
Views: 74

Re: nitro vs nitrito

If you look on the sheet, for nitro, the N is underlined which indicates that nitrogen is the atom that is linked to the metal atom, whereas in nitrito, oxygen is the linked atom.
by Christine Chow 4G
Mon Dec 03, 2018 3:46 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ch.17-#31b (6th edition) Coordination Compounds
Replies: 2
Views: 81

Re: Ch.17-#31b (6th edition) Coordination Compounds

when you write the chemical formula of a coordination compound, you are suppose to put the ligands in alphabetical order (so NH3 before SO4)
by Christine Chow 4G
Mon Dec 03, 2018 3:40 pm
Forum: Naming
Topic: Determining oxidation number
Replies: 5
Views: 144

Re: Determining oxidation number

In [Co(CN)5 (OH2)]^-2, the oxidation number for Co is +3 because OH2 has a charge of 0 and CN has a charge of -1. In order for the final charge to be -2, Co has to be +3. -5 +3 = -2 In [Co(NH3)5(SO4)]+ the oxidation number for Co is 3+ because (NH3)5 has a charge of 0 and (SO4) has a charge of 2- In...
by Christine Chow 4G
Mon Nov 26, 2018 4:05 pm
Forum: General Science Questions
Topic: Test 3
Replies: 4
Views: 153

Re: Test 3

I don't believe it will, it should be up to outline four (lignads and coordination compounds are in outline five).
by Christine Chow 4G
Mon Nov 26, 2018 4:02 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 3
Views: 108

Re: Cisplatin

Cisplatin has the two chlorine atoms on the same side of the molecule (vs on opposite sides). When it binds to the guanine base on the DNA molecule, a chlorine is released from cisplatin and binds to a lone pair on the guanine. Since there are two chlorines next to each other, the cisplatin can bind...
by Christine Chow 4G
Mon Nov 26, 2018 3:56 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligand
Replies: 4
Views: 95

Re: Ligand

Ligands are the molecules/atoms attached to a central ion in a coordination compound that donates its electron pair. Some examples of ones we talked about in class are cyanide (CN-), the halogens (F-,Cl-,Br-,I-), amine (NH3).
by Christine Chow 4G
Mon Nov 26, 2018 3:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR shape
Replies: 4
Views: 96

Re: VSEPR shape

While it is true that trigonal pyrimidal and T shape have the same amount of atoms, the number of lone pairs attached to the central atom makes these two molecules different (you must consider the electron geometry of the molecule too!). If you were to consider the electron geometry of the trigonal ...
by Christine Chow 4G
Mon Nov 19, 2018 1:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle
Replies: 8
Views: 160

Re: Bond Angle

Why is the axial bond angle of a seesaw molecule less than 180 degrees but the axial bond angle of a T shape molecule is 180 degrees? Does the T shape molecule not also experience electron repulsions from the lone pairs in the equitorial plane?
by Christine Chow 4G
Mon Nov 19, 2018 1:13 pm
Forum: Hybridization
Topic: hybridization
Replies: 2
Views: 63

Re: hybridization

the greater the s character, the closer the orbitals are to the nucleus. This will give the molecule a stronger bond, so sp3<sp2<sp.
by Christine Chow 4G
Mon Nov 19, 2018 1:09 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Electron geometry vs Molecular geometry
Replies: 3
Views: 87

Re: Electron geometry vs Molecular geometry

electron geometry is the arrangement of electron groups around a central atom whereas molecular geometry deals with the arrangement of atoms (excluding lone pairs)
by Christine Chow 4G
Mon Nov 19, 2018 1:01 pm
Forum: Administrative Questions and Class Announcements
Topic: Exam 3 Topics [ENDORSED]
Replies: 6
Views: 226

Re: Exam 3 Topics [ENDORSED]

I'm not completely sure, but what I have in my notebook is that that we should study different types of bonds (strength/length), VSEPR and molecular shape, intermolecular interactions, and other stuff in outline four.
by Christine Chow 4G
Mon Nov 12, 2018 5:19 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: London Forces v Dipole-Induced Dipole
Replies: 2
Views: 62

Re: London Forces v Dipole-Induced Dipole

London forces are basically induced dipole-induced dipole forces. A dipole-induced dipole force would be stronger because the dipole allows for a stronger attraction to the other (induced dipole-induced dipole) molecule than an induced dipole-induced dipole force's attraction to another induced dipo...
by Christine Chow 4G
Mon Nov 12, 2018 5:16 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Distortion
Replies: 3
Views: 104

Re: Distortion

Atoms with valence electrons in further shells from the nucleus experience less attraction from the nucleus. These electrons are not held onto as strongly and are able to be attracted by other atom's positive charges, therefore when a small cation such as Na+ is near a large atom with electrons far ...
by Christine Chow 4G
Mon Nov 12, 2018 5:05 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: Dipoles and Electronegativity
Replies: 4
Views: 109

Re: Dipoles and Electronegativity

Yes, if the difference in electronegativity values between the two atoms bonded together is greater than 0.5, there will be a dipole moment. If it is less than 0.5, like in a C-H bond, we would consider the bond to have a very weak dipole moment.
by Christine Chow 4G
Mon Nov 12, 2018 4:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 6
Views: 116

Re: Molecular Shape

A solid line means the atoms share and intramolecular bond (and are bonded together to make up a molecule or compound). Dashed lines represent interactions/intermolecular forces between these molecules or compounds.
by Christine Chow 4G
Tue Nov 06, 2018 9:20 pm
Forum: Octet Exceptions
Topic: Octet rule vs. Formal charge
Replies: 7
Views: 188

Re: Octet rule vs. Formal charge

For elements with expanded octets, is there no maximum number of bonds it's allowed to have? Is it just the number of bonds that will satisfy the lowest formal charge rule? Yes as long as the element doesn't exceed the amount of valence electrons it has (which should not be a problem because formal...
by Christine Chow 4G
Tue Nov 06, 2018 9:08 pm
Forum: Bond Lengths & Energies
Topic: Bond Lengths
Replies: 6
Views: 143

Re: Bond Lengths

I think you should generally have the idea that single bonds are longer than double bonds which are longer than triple bonds and the ionic/covalent bond trend for the periodic table. For exact numbers, I highly doubt he would have us memorize exact numbers unless he specifically tells us to.
by Christine Chow 4G
Tue Nov 06, 2018 9:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: HW for discussion
Replies: 9
Views: 261

Re: HW for discussion

I believe anything from the third outline will suffice.
by Christine Chow 4G
Tue Nov 06, 2018 9:03 pm
Forum: Lewis Structures
Topic: expanded octet
Replies: 2
Views: 106

Re: expanded octet

We know by looking at the periodic table that Bromine has 7 valence electrons. If you have Bromine make 6 bonds, there will be one valence electron left over (which would make it a radical and not the most stable Lewis structure). However, if Bromine had 5 bonds and one lone pair, it satisfies the F...
by Christine Chow 4G
Sun Nov 04, 2018 11:18 am
Forum: Administrative Questions and Class Announcements
Topic: Midterm Exam Time Conflict
Replies: 2
Views: 109

Re: Midterm Exam Time Conflict

I think you should just take the l in your english class to make it to the midterm. When I read the syllabus, he said there wouldn't be any make up tests and that if there were conflicts you should've talked to your TA like week one (unless you were sick and have a doctors note)
by Christine Chow 4G
Tue Oct 30, 2018 3:58 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Perchlorate (ClO4)-
Replies: 7
Views: 2360

Re: Perchlorate (ClO4)-

No, I believe 3 of the oxygens bonded to the chlorine are double bonded, so these would have a formal charge of 0. The one oxygen single bonded by chlorine will have a formal charge of -1.
by Christine Chow 4G
Mon Oct 29, 2018 9:30 pm
Forum: Trends in The Periodic Table
Topic: Ionization energies
Replies: 9
Views: 260

Re: Ionization energies

I believe oxygen has a lower ionization energy due to the fact that its 8th electron becomes paired (the up and down spin) versus filling a new orbital. There would be more electron repulsion in this pair versus the other 3p electrons that are in their own orbital (x,y,z)
by Christine Chow 4G
Mon Oct 29, 2018 9:05 pm
Forum: *Particle in a Box
Topic: Midterm
Replies: 17
Views: 1133

Re: Midterm

Also how is the midterm formatted, will it be similar to the tests we have taken before or will they be multiple choice?
by Christine Chow 4G
Mon Oct 29, 2018 9:03 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 2
Views: 103

Re: Electron Affinity

i think the trend is as you go higher up the periodic table and to the right, elements will have a higher electron affinity. electron affinity is determined by the attraction of electrons to the nucleus, so the more protons an element has (going to the right of the periodic table), the higher the el...
by Christine Chow 4G
Mon Oct 29, 2018 4:58 pm
Forum: Bond Lengths & Energies
Topic: Bond Lengths
Replies: 3
Views: 113

Re: Bond Lengths

Dr. Lavelle said during class that he had found them online. I don't think you need to know how to get these values or anything, it was just to demonstrate how the expected bond lengths did not coincide with the experimentally observed bond lengths.
by Christine Chow 4G
Mon Oct 22, 2018 4:32 pm
Forum: Quantum Numbers and The H-Atom
Topic: HW 2.19
Replies: 3
Views: 92

Re: HW 2.19

I have a question about 2.19 regarding part d. I understand that from n=4 equates to n-1=3 and l=3. Therefore, there are s, p, d, and f suborbitals but I don't understand why the answer says the suborbitals are 4s, 4p, 4d, and 4f. What are the 4's for? because you are looking at the shell level n=4...
by Christine Chow 4G
Mon Oct 22, 2018 4:25 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Ionization
Replies: 1
Views: 38

Re: Ionization

ionization is the process in which an atom becomes positively or negatively charged by either losing or gaining electrons.
by Christine Chow 4G
Mon Oct 22, 2018 4:23 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Group 5 Transition Metals
Replies: 1
Views: 386

Group 5 Transition Metals

2.55 C asks for the electron configuration for Group 5 transition metals, which I thought was just group 5 on the periodic table, but it is apparently the fifth group of the periodic table. Would it be incorrect to call this Group 7?
by Christine Chow 4G
Mon Oct 22, 2018 4:19 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: The Structure of Many-Electron Atoms 2.37B
Replies: 1
Views: 48

The Structure of Many-Electron Atoms 2.37B

The question asks if the statement is true or false: Electrons in an s-orbital are more effective than those in other orbitals at shielding other electrons from the nuclear charge because an electron in an s-orbital can penetrate to the nucleus of the atom. I originally thought it was false because ...
by Christine Chow 4G
Mon Oct 15, 2018 6:46 pm
Forum: Einstein Equation
Topic: Einstein's Equation: E=hv
Replies: 11
Views: 345

Re: Einstein's Equation: E=hv

Lavelle posted the formula sheet he will be giving us on tests on his website so if you ever want to check which numbers/equations he will give to us, it will be there for your reference
by Christine Chow 4G
Mon Oct 15, 2018 6:41 pm
Forum: Properties of Electrons
Topic: Free vs. Bound Electrons
Replies: 6
Views: 143

Re: Free vs. Bound Electrons

Yes. if they are bound to the nucleus then the electrons are bounded electrons (regardless of whether they are valence or non valence)
by Christine Chow 4G
Mon Oct 15, 2018 4:57 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Indeterminacy in position
Replies: 2
Views: 114

Re: Indeterminacy in position

first, you would want to convert the radius from nm to m. To find the total uncertainty of the position, you need to find the diameter of the atom (since they gave you the radius). You multiply this total uncertainty by the percent accuracy (1%) to get Δx and you can solve for Δv using (ΔxΔp≥h/4Π) w...
by Christine Chow 4G
Mon Oct 15, 2018 4:41 pm
Forum: Properties of Light
Topic: Test 2
Replies: 17
Views: 296

Re: Test 2

There are a total of 5 tests in the quarter and 6 outlines, so I'm just assuming whatever material we cover before the first discussion takes the test will be what's on the test.
by Christine Chow 4G
Sun Oct 07, 2018 9:09 pm
Forum: Significant Figures
Topic: Calculating process
Replies: 5
Views: 405

Re: Calculating process

if you are given 33 grams in the problem, then yes your answer would be to two sigfigs. You can round during the calculations and if you do it all correctly you should get full credit. However, I tend to round at the very end because if you round too early, it could make you answer be off by a lot.
by Christine Chow 4G
Sun Oct 07, 2018 9:06 pm
Forum: Significant Figures
Topic: Sig Figs in the Middle of a Problem
Replies: 9
Views: 526

Re: Sig Figs in the Middle of a Problem

My TA said that you can wait to round the sig figs until the end because if you round in the middle of a calculation, it could mess up your final answer (but if you do use the proper sig figs during the calculation and do everything right, even if your answer is off a little you still get the points...
by Christine Chow 4G
Sun Oct 07, 2018 8:56 pm
Forum: Properties of Light
Topic: Formula for energy of a photon
Replies: 4
Views: 68

Re: Formula for energy of a photon

i dont have the seventh edition, but the energy of a photon = h (Planck's constant)* v (frequency)
by Christine Chow 4G
Sun Oct 07, 2018 8:03 pm
Forum: Administrative Questions and Class Announcements
Topic: WHAT TYPE OF CALCULATOR IS ALLOWED ON EXAMS??
Replies: 5
Views: 192

Re: WHAT TYPE OF CALCULATOR IS ALLOWED ON EXAMS??

the ti 30 should be fine, thats what I used in high school when my teacher banned graphing calculators.
by Christine Chow 4G
Sun Oct 07, 2018 11:08 am
Forum: Administrative Questions and Class Announcements
Topic: WHAT TYPE OF CALCULATOR IS ALLOWED ON EXAMS??
Replies: 5
Views: 192

Re: WHAT TYPE OF CALCULATOR IS ALLOWED ON EXAMS??

no graphing calculator but scientific is okay, he just said a basic calculator that you would only pay 10$ for so it shouldn't be something that you can store information on
by Christine Chow 4G
Tue Oct 02, 2018 7:01 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: number of moles, molecules, and formula units?
Replies: 3
Views: 79

Re: number of moles, molecules, and formula units?

so avogadro's number is a constant, 6.022*10^23 to be exact. In one mole, there are 6.022*10^23 "things". These things can be either atoms, molecules, or formula units depending on what type of question you are dealing with. From what I understand, a formula unit is basically a molecule fo...
by Christine Chow 4G
Tue Oct 02, 2018 10:59 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: rounding [ENDORSED]
Replies: 10
Views: 371

Re: rounding [ENDORSED]

You can round the 6.01 to 6. I would say if it isn't more than 0.1 off of a whole number, then you should round but i dont know if there's a rule for this.
by Christine Chow 4G
Tue Oct 02, 2018 10:30 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: rounding [ENDORSED]
Replies: 10
Views: 371

Re: rounding [ENDORSED]

There are different rules for sig figs for when you multiply/divide versus adding/subtracting. For multiplying/dividing you count which number has the least amount of sig figs and use that amount in your answers. For adding/subtracting, you use the number with the least decimal places to determine w...
by Christine Chow 4G
Mon Oct 01, 2018 7:49 pm
Forum: Balancing Chemical Reactions
Topic: Balance Equation L.35
Replies: 6
Views: 281

Re: Balance Equation L.35

You don't necessarily need a final balanced equation. You can take the give information (2.5 t of NaBr) and convert this to moles. Then you can work backwards (from the last equation to the first) to figure out how many moles of Fe were needed to make the NaBr using dimensional analysis (but you wou...

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