## Search found 33 matches

Sat Dec 08, 2018 12:55 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Why HClO2 is a stronger acid than HBrO2?
Replies: 6
Views: 8425

### Re: Why HClO2 is a stronger acid than HBrO2?

Is this true every time there's an O2 in an acid? The hydrogen will be bound to one oxygen?
Sat Dec 08, 2018 12:21 pm
Forum: Calculating the pH of Salt Solutions
Topic: sigfigs for calculating pH
Replies: 1
Views: 275

### sigfigs for calculating pH

If we are given a concentration and a molarity and asked to calculate pH, which value's sigfigs should we look at to base our answers off of? For example, if we are told it's a 1L of a 2.4 M solution, would our answer have 1 sig fig or 2? I'm confused because in the book for example we were told to ...
Sat Dec 08, 2018 11:40 am
Forum: Identifying Acidic & Basic Salts
Topic: 12.25 6th Edition
Replies: 1
Views: 226

### 12.25 6th Edition

It asks to calculate the initial molarity of Ba(OH)2 and the molarities of Ba+, OH-, and H3O+ in an aqueous solution that contains 0.43 g Ba(OH)2 on 0.100 L of solution. I don't understand how to find the molarity of H3O+ because I don't know the mole ratio since I thought that the equation would ju...
Sat Dec 08, 2018 12:25 am
Forum: Polyprotic Acids & Bases
Topic: H2SO4 vs H2CO3
Replies: 4
Views: 1022

### H2SO4 vs H2CO3

If both H2SO4 and H2CO3 are polyprotic acids, why is sulfuric acid a strong acid but carbonic acid is not? Is it because although carbonic acid CAN donate its 2 H+s, it's very unlikely to? Why then does sulfuric readily donate one H+ to make HSO4- ?
Fri Dec 07, 2018 11:06 pm
Forum: Administrative Questions and Class Announcements
Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
Replies: 118
Views: 11190

### Re: FINAL PRACTICE - Lyndon's Churro Review Session[ENDORSED]

On question 21, can someone explain why Fe has an oxidation state of +2? I get that this is because of the nitrogens, but how do the nitrogens come to have a charge of -2? I was trying to calculate the formal charge but kept getting a positive charge on the nitrogens, not a negative charge. This is...
Wed Dec 05, 2018 2:06 pm
Forum: Administrative Questions and Class Announcements
Replies: 135
Views: 31255

Angela Cordova 3F wrote:These worksheets have helped me so much on the tests, will there be any covering the topics for Test 3?

Worksheets 6 and 7 above pretty much cover the same topics that Test 3 did!
Wed Dec 05, 2018 2:06 am
Forum: Naming
Topic: Cyanide (cyano vs isocyano)
Replies: 2
Views: 161

### Cyanide (cyano vs isocyano)

Under the list of Anionic Ligands (from the Naming Coordination Compounds link on Dr. Lavelle's website) there is the name cyano for when cyanide is bound to the transition metal at the carbon, but there is also the name isocyano for when cyanide binds at the nitrogen. I thought that cyanide was alw...
Wed Dec 05, 2018 1:18 am
Forum: Administrative Questions and Class Announcements
Topic: Step Up Session Worksheet (Monday + Friday, Hannah) [ENDORSED]
Replies: 37
Views: 2068

### Re: Step Up Session Worksheet (Monday + Friday, Hannah)[ENDORSED]

You said that in order for hydrogen bonding to occur, the hydrogen in the individual molecule has to be bound to either O,N, or F to hydrogen bond with another molecule, but in CH3CH2OCH2CH3, none of the hydrogens are actually bound to the oxygen, but in number 3 d. of this worksheet, it says that ...
Sat Dec 01, 2018 3:33 pm
Forum: Administrative Questions and Class Announcements
Replies: 135
Views: 31255

On Worksheet 6, #1 it asks to draw the most stable lewis structure for nitrogen dioxide (NO2), to determine the shape, and determine whether or not it it polar. In the key, the lewis structure is drawn with one single bond between nitrogen and oxygen and one double bond between nitrogen and the oth...
Thu Nov 29, 2018 11:06 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Session Worksheet (Monday + Friday, Hannah) [ENDORSED]
Replies: 37
Views: 2068

### Re: Step Up Session Worksheet (Monday + Friday, Hannah)[ENDORSED]

You said that in order for hydrogen bonding to occur, the hydrogen in the individual molecule has to be bound to either O,N, or F to hydrogen bond with another molecule, but in CH3CH2OCH2CH3, none of the hydrogens are actually bound to the oxygen, but in number 3 d. of this worksheet, it says that ...
Thu Nov 29, 2018 8:47 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Session Worksheet (Monday + Friday, Hannah) [ENDORSED]
Replies: 37
Views: 2068

### Re: Step Up Session Worksheet (Monday + Friday, Hannah)[ENDORSED]

You said that in order for hydrogen bonding to occur, the hydrogen in the individual molecule has to be bound to either O,N, or F to hydrogen bond with another molecule, but in CH3CH2OCH2CH3, none of the hydrogens are actually bound to the oxygen, but in number 3 d. of this worksheet, it says that C...
Thu Nov 29, 2018 8:17 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Session Worksheet (Monday + Friday, Hannah) [ENDORSED]
Replies: 37
Views: 2068

### Re: Step Up Session Worksheet (Monday + Friday, Hannah)[ENDORSED]

On the Week 6 Step-Up, why is #1a. only dipole-dipole and dispersion forces? Isn't there hydrogen bonding also between the hydrogen of one CH3CF3 and the fluorine of another CH3CF3 molecule? No, the H in the individual molecule must have hydrogen bonded to N, O, or F first for the interaction youre...
Thu Nov 29, 2018 6:46 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: Is Hydrogen Bonding a type of Dipole-Dipole Interaction?
Replies: 5
Views: 195

### Is Hydrogen Bonding a type of Dipole-Dipole Interaction?

So is hydrogen bonding just a specific type of dipole-dipole interaction? If so, if we say two molecules have hydrogen bonding, then is it implied that there are dipole-dipole interactions between them also so that we don't have to state that explicitly?
Thu Nov 29, 2018 6:36 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Session Worksheet (Monday + Friday, Hannah) [ENDORSED]
Replies: 37
Views: 2068

### Re: Step Up Session Worksheet (Monday + Friday, Hannah)[ENDORSED]

On the Week 6 Step-Up, why is #1a. only dipole-dipole and dispersion forces? Isn't there hydrogen bonding also between the hydrogen of one CH3CF3 and the fluorine of another CH3CF3 molecule?
Thu Nov 29, 2018 1:51 am
Forum: Administrative Questions and Class Announcements
Replies: 135
Views: 31255

On Worksheet 6, #1 it asks to draw the most stable lewis structure for nitrogen dioxide (NO2), to determine the shape, and determine whether or not it it polar. In the key, the lewis structure is drawn with one single bond between nitrogen and oxygen and one double bond between nitrogen and the othe...
Wed Nov 28, 2018 12:49 am
Forum: Dipole Moments
Topic: Drawing dipole moments
Replies: 3
Views: 155

### Re: Drawing dipole moments

I was also confused by this because it's drawn one way in the textbook but my TA drew it the opposite way in discussion. SO, by drawing "from positive to negative" do you mean with the arrowhead (<) on the negative dipole and the tail on the positive dipole?
Tue Nov 27, 2018 9:56 pm
Forum: Bond Lengths & Energies
Topic: Bond Length (Chapter 3.16 of 6th Edition)
Replies: 1
Views: 146

### Bond Length (Chapter 3.16 of 6th Edition)

In the textbook it says that multiple bonds are shorter than single bonds between the same two elements, but doesn't that also apply to bonds between different elements? Ex: CO, CO2, CO3^2-. The two elements are different, but when I drew out the Lewis structures for all three of them, that rule sti...
Sun Nov 04, 2018 9:58 pm
Forum: Administrative Questions and Class Announcements
Replies: 135
Views: 31255

For #8, which asks for the full electron configuration of Nitrogen, would 1s^22s^22p^3 be wrong? Do we have to write out 2px^1 2py^1 2pz^1?
Sun Nov 04, 2018 9:51 pm
Forum: Administrative Questions and Class Announcements
Replies: 135
Views: 31255

Thank you! For 6.b. isn't it asking for the work energy/ the threshold energy? In the solution, E=hv is used to find energy, but I thought that was energy of the incoming photon and it's asking how much energy is required to remove the electron. So wouldn't you find the kinetic energy of the photon ...
Sun Nov 04, 2018 2:42 pm
Forum: Quantum Numbers and The H-Atom
Topic: s,p,d,f
Replies: 8
Views: 414

### Re: s,p,d,f

How do you know that/when the d-orbital has to fill before the s-orbital? For example, why is the electron configuration of Cu+: [Ar]3d^10 rather than [Ar]3d^94s^1. Is it whenever the d-orbital has either 4 electrons (one in each orbital) or 9 electrons (all but one orbital are spin paired) that you...
Sun Nov 04, 2018 2:42 pm
Forum: Quantum Numbers and The H-Atom
Topic: s,p,d,f
Replies: 8
Views: 414

### Re: s,p,d,f

How do you know that/when the d-orbital has to fill before the s-orbital? For example, why is the electron configuration of Cu+: [Ar]3d^10 rather than [Ar]3d^94s^1. Is it whenever the d-orbital has either 4 electrons (one in each orbital) or 9 electrons (all but one orbital are spin paired) that you...
Sun Nov 04, 2018 1:46 pm
Forum: Administrative Questions and Class Announcements
Replies: 135
Views: 31255

Has the key been posted for midterm review worksheet #5?
Tue Oct 23, 2018 3:51 pm
Forum: Photoelectric Effect
Topic: Module Question 32.B
Replies: 1
Views: 154

### Module Question 32.B

The question is: In a second experiment a shorter wavelength light source is used resulting in ejected electrons with a kinetic energy of 4.200 x 10-19 J. What is the energy of this incident light? What is the wavelength of this incident light? (We were already told that 3.607 x 10-19 J is required ...
Tue Oct 23, 2018 3:40 pm
Forum: Photoelectric Effect
Topic: Question 28B on Post Module Assessment for Photoelectric Effect
Replies: 1
Views: 149

### Question 28B on Post Module Assessment for Photoelectric Effect

The question is: Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 105 m.s-1. The work function for sodium is 150.6 kJ.mol-1. Then it asks: How much energy is required to remove an electron from one sodium atom? In other words, it's asking for the threshold energy ...
Sun Oct 21, 2018 4:49 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Topics We Need to Know for the Test [ENDORSED]
Replies: 5
Views: 237

### Re: Topics We Need to Know for the Test[ENDORSED]

Hi! Do we need to know how to derive the three fundamental equations (DeBroglie's, Heisenberg's, and Schrodinger's)?
Sun Oct 21, 2018 4:46 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Confusion with problem 1.57 [ENDORSED]
Replies: 4
Views: 495

### Re: Confusion with problem 1.57[ENDORSED]

Will we be tested on the Balmer series in Test 2?
Sun Oct 21, 2018 4:41 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Confusion with problem 1.57 [ENDORSED]
Replies: 4
Views: 495

### Re: Confusion with problem 1.57[ENDORSED]

Will we be tested on the Balmer series in Test 2?
Sun Oct 21, 2018 4:37 pm
Forum: Einstein Equation
Topic: The symbol v?
Replies: 16
Views: 1830

### Re: The symbol v?

Hi! Will we be marked down if our nu looks like a v in the E=h v equation? Because on the homework I just used v and if I'm rushing on the test, it'll probably be hard to distinguish my v from my nu. Also, nu represents frequency but in other light equations it showed up as v, so are they interchang...
Sun Oct 21, 2018 4:36 pm
Forum: Einstein Equation
Topic: The symbol v?
Replies: 16
Views: 1830

### Re: The symbol v?

Hi! Will we be marked down if our nu looks like a v in the E=h v equation? Because on the homework I just used v and if I'm rushing on the test, it'll probably be hard to distinguish my v from my nu. Also, nu represents frequency but in other light equations it showed up as v, so are they interchang...
Sun Oct 21, 2018 4:30 pm
Forum: Quantum Numbers and The H-Atom
Topic: Homework Problem 1.13 (Sixth Edition)
Replies: 1
Views: 43

### Homework Problem 1.13 (Sixth Edition)

We had to use the Rydberg equation for this problem and we were told that the electron went from n=4 to n=2, so I assumed that n1=4 and n2=2. That resulted in a negative number because the formula is R * (1/n1^2 - 1/n2^2), so it ended up being R* (-3/16) (because 1/16 - 4/16 = -3/16), and that answe...
Sun Oct 14, 2018 10:20 pm
Forum: Significant Figures
Topic: Module: Molarity #15
Replies: 6
Views: 647

### Re: Module: Molarity #15

You wouldn't round up to 0.3?
Sun Oct 14, 2018 10:14 pm
Forum: Empirical & Molecular Formulas
Topic: Going from empirical to Molecular formula
Replies: 14
Views: 962

### Re: Going from empirical to Molecular formula

How do you go from the molecular formula to the empirical formula if you aren't given a molar mass by mass spectrometry to compare to (and divide by) the molar mass you calculate using the molecular formula? In other words, how would we know what factor the empirical formula was multiplied by in ord...
Sun Oct 14, 2018 9:58 pm
Forum: Limiting Reactant Calculations
Topic: Test 1
Replies: 8
Views: 657

### Re: Test 1

BY modules, do you guys mean the post-tests/surveys in the audio visual focus topics on his website? Or is that something else?