## Search found 22 matches

Wed Dec 06, 2017 1:39 pm
Forum: Octet Exceptions
Topic: Octet Exceptions
Replies: 8
Views: 603

### Re: Octet Exceptions

Could someone please summarize all the exceptions we need to be aware of for chemical bonds? I know of:
1. S, P, Xe, and the halogens can have an expanded octet
2. Be and B can have less than 8

Is there anything I am missing?
Wed Dec 06, 2017 12:48 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: ICE Chart [ENDORSED]
Replies: 9
Views: 565

### Re: ICE Chart[ENDORSED]

The general rule for this is that the reactants will have a -X and the products will have a +X. This makes sense because the products are initially starting with 0, so they have to have something added.
Wed Dec 06, 2017 12:45 pm
Forum: Lewis Acids & Bases
Topic: Memorizing Acids and Bases
Replies: 7
Views: 530

### Re: Memorizing Acids and Bases

Are there any exceptions to the trends on the periodic table for Ch.17?
Tue Nov 28, 2017 11:10 pm
Forum: Naming
Topic: 17.31 a
Replies: 1
Views: 195

### Re: 17.31 a

I am also struggling to understand why the three goes with the potassium instead of the chromium.
Mon Nov 27, 2017 2:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Homework 4.13
Replies: 3
Views: 314

### Homework 4.13

For part b in homework problem 13 in chapter 4, it wants you to write the Lewis structure for POCl3. The answer has P as the central atom and Cl, Cl, Cl, and O surrounding it in a tetrahedral shape. However, oxygen has a double bond. How do you know that oxygen has a double bond and it doesn't just ...
Sun Nov 26, 2017 11:32 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Chemical Equilibrium
Replies: 3
Views: 237

### Re: Chemical Equilibrium

Are there any specific exceptions we should be aware of for Chemical Equilibrium (in some other chapters there are specific exceptions to know, like chromium and copper for the orbitals)?
Sun Nov 26, 2017 11:30 am
Forum: Naming
Topic: Naming (steps)
Replies: 6
Views: 453

### Re: Naming (steps)

To determine what Roman numeral to put after a transition metal, you must first identify the charge of every other element in the compound. You then add up the charges of all of the other elements, and the transition metal charge will be whatever will make that compound have charge of 0. So if the o...
Sun Nov 26, 2017 11:27 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Q vs. K
Replies: 3
Views: 275

### Re: Q vs. K

So it is possible for Q and K to be equal, if Q is at equilibrium?
Thu Nov 16, 2017 10:52 am
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.1 Lone pairs
Replies: 6
Views: 490

### Re: 4.1 Lone pairs

In the second diagram posted above, can someone please explain the significance of the thicker line and the dotted line?
Thu Nov 16, 2017 10:49 am
Forum: Hybridization
Topic: Order of s,p,d in Names of Hybrid Orbitals
Replies: 3
Views: 290

### Re: Order of s,p,d in Names of Hybrid Orbitals

I am still confused as to why the order does not matter in hybrids. Could I get more clarity on this issue?
Thu Nov 09, 2017 1:28 am
Forum: Dipole Moments
Topic: Bond length [ENDORSED]
Replies: 4
Views: 399

### Re: Bond length[ENDORSED]

What is the bond length of a resonance structure? For example, if the resonance structure is NO3, would the bond lengths be in-between the length of a single and double bond?
Thu Nov 09, 2017 1:25 am
Forum: Ionic & Covalent Bonds
Topic: 3.25 d
Replies: 3
Views: 316

### Re: 3.25 d

What specific formulas will we have to have memorized? Problem #25 requires you to give the chemical formula, but some (including in other problems) would only be known from memorization.
Tue Oct 31, 2017 12:46 am
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 4
Views: 369

### Re: Electron Affinity

#67 in Chapter 2 asks which element has the higher electron affinity. Part b asks you to compare nitrogen and carbon. I thought the answer would be nitrogen because nitrogen is more towards the right of the periodic table (I believe that electron affinity is higher towards the top right of the perio...
Mon Oct 30, 2017 11:30 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 2.47 [ENDORSED]
Replies: 2
Views: 295

### 2.47[ENDORSED]

Question #47 for Chapter 2: For each of the following ground-state atoms, predict the type of orbital (1s, 2p, 3d, 4f, etc.) from which an electron will be removed to form the +1 ion: a) Ge; b) Mn; c) Ba; d) Au. Can someone please explain why the answers are: a)4p b)4s c)6s d)6s I figured the answer...
Tue Oct 24, 2017 2:56 pm
Forum: Properties of Light
Topic: Problem 1.55
Replies: 4
Views: 383

### Re: Problem 1.55

I am also struggling with this problem. How would you know to use the equation E=v/c? And why is an absorption, with units in cm, considered energy?
Tue Oct 24, 2017 2:33 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Chapter 1 #43 [ENDORSED]
Replies: 7
Views: 565

### Re: Chapter 1 #43[ENDORSED]

Can someone explain why you do h/2pi? Are there any other situations that we need to be aware of where h is divided by 2pi?
Wed Oct 18, 2017 12:22 am
Forum: DeBroglie Equation
Topic: 1.37 [ENDORSED]
Replies: 5
Views: 441

### Re: 1.37[ENDORSED]

On #37 and #41, you need to know the mass of a proton and neutron, which are not given in the question. Is this something we should memorize for tests? Are there any other masses that we should memorize the value of?
Wed Oct 18, 2017 12:15 am
Forum: DeBroglie Equation
Topic: CHAPTER 1 QUESTION 33!!!
Replies: 8
Views: 594

### Re: CHAPTER 1 QUESTION 33!!!

I also have a question on #33, but not related to what is above. I am wondering how, in part a, you get the mass? The answer in the book says that the mass is 9.1*10^-31, but that is not given in the question and I am unsure how you would figure that out.
Wed Oct 11, 2017 12:39 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Using the Rydberg Equation
Replies: 4
Views: 299

### Re: Using the Rydberg Equation

Is it essential to memorize which series corresponds to each n? And what wavelengths correspond to each series?
Wed Oct 11, 2017 11:55 am
Forum: Properties of Light
Topic: 1.13
Replies: 2
Views: 292

### 1.13

Question 1.13 asks you to use the Rydberg formula for atomic hydrogen to calculate the wavelength of radiation generated by the transition from n=4 to n=2. I got the equation 2.988x10^8 = 3.29x10^15((1/16) - (1/4)) x wavelength. Therefore, I thought n1=16 and n2=4, but the answer is flipped. If the ...
Wed Oct 11, 2017 11:11 am
Forum: Properties of Light
Topic: Chapter 1 #3
Replies: 9
Views: 561

### Re: Chapter 1 #3

I understand why a. and b. are incorrect, but can someone please explain why d. is wrong? Wouldn't energy increase if the frequency decreases (as in the equation E=hv).
Wed Oct 11, 2017 10:33 am
Forum: Properties of Light
Topic: Chapter 1 Question 9
Replies: 4
Views: 357

### Re: Chapter 1 Question 9

To clarify, is Hz always interchangeable with s^-1 when solving frequency/wavelength problems? Is any multiplication or division required for the conversion?