## Search found 25 matches

Tue Dec 05, 2017 10:34 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Problem 12.69
Replies: 4
Views: 339

### Re: Problem 12.69

Sorry never mind, I found the value on table 12.8
Tue Dec 05, 2017 10:14 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Problem 12.69
Replies: 4
Views: 339

### Re: Problem 12.69

For part b, the Ka is given as 1.4 x 10^-5. I tried looking for the Ka or Kb (and then converting it to Ka) on the table but I couldn't find it. I was wondering how they got the value.
Thu Nov 30, 2017 8:51 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's Principle
Replies: 2
Views: 196

### Le Chatelier's Principle

Can someone explain the Le Chatelier's principle please? Does concentration and partial pressure have the same effect on the reaction? For example, in problem 11.69 a) why does increasing the partial pressure of the reactant CO2 result in creation of more reactants and thus decrease the partial pres...
Thu Nov 30, 2017 8:45 pm
Forum: Identifying Acidic & Basic Salts
Topic: Identifying strong acids and bases
Replies: 2
Views: 280

### Identifying strong acids and bases

What makes an acid or base strong or weak? Do we have to memorize all the weak and strong acids and bases or can we determine which one is weak or strong by drawing the lewis structures?
Mon Nov 27, 2017 5:55 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE Box
Replies: 1
Views: 111

### ICE Box

For the ICE box method, will the x for change in molarity for the reactant always be negative (-x)?
Tue Nov 21, 2017 9:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Ch 11 # 1
Replies: 2
Views: 155

### Re: Ch 11 # 1

Sorry can you explain more about how an increase in reactants will cause a shift towards increased products in order to restore equilibrium because based on this equation: K= Concentration of P/ Concentration of R. Doesn't that mean if the concentration of R increases, the concentration of P will de...
Tue Nov 21, 2017 9:46 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Ch.11 #1(c)
Replies: 1
Views: 102

### Ch.11 #1(c)

Can someone explain to me why the answer for 11.1c is false. Why is the equilibrium constant not affected if the pressure of the reactant is higher? If the pressure of the reactant is higher, doesn't that mean temperature is also higher?
Sun Nov 19, 2017 8:40 pm
Forum: Hybridization
Topic: 4.33 (c)
Replies: 2
Views: 189

### 4.33 (c)

Why is the answer for 4.33c (the compound is BH4^-) sp^3? To determine the hybridization, should I look at Boron (B) or should I consider the number of areas with electron density?
Sun Nov 19, 2017 8:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.25 (Polarity)
Replies: 4
Views: 219

### 4.25 (Polarity)

For questions similar to 4.25, how do you determine if the compound is polar or non polar? If the dipole cancels, then it is non polar, right?
Sun Nov 12, 2017 9:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.1
Replies: 5
Views: 181

### 4.1

For 4.1, how does the bond angle determine if the molecule "must have lone pairs" or "may have lone pairs?" If there is a lone pair for part B, will the shape of the molecule still be linear?
Sun Nov 12, 2017 9:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.5
Replies: 2
Views: 182

### 4.5

Why is the shape of ClO2+ angular? Does it have to do with polarity/ dipole moments?
Tue Nov 07, 2017 11:26 am
Forum: Bond Lengths & Energies
Topic: Bond Length
Replies: 8
Views: 1139

### Bond Length

How do we know if the bond length is long or short? Is their a pattern? For example, in the lecture Lavelle arranged from long bond length to short bond length that HF<HCl<HI. How did he get that? In another example, how would I arrange these molecules from shortest bond length to longest bond lengt...
Tue Nov 07, 2017 11:19 am
Forum: Dipole Moments
Topic: Finding Dipole Moments
Replies: 3
Views: 428

### Finding Dipole Moments

How do we find the dipole moment from a lewis structure? Do we use the equation to find the formal charge? Are their dipole moments for lewis structures with resonance?
Thu Oct 26, 2017 9:15 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic vs. Covalent Bonds [ENDORSED]
Replies: 8
Views: 456

### Ionic vs. Covalent Bonds[ENDORSED]

Can someone explain the difference to me between a covalent and ionic bond? I know that a covalent bond, two atoms/ elements share electrons, and with ionic bonds metals give up and electrons while the nonmetal gains an electron. Why do elements want achieve noble gas configuration? Also, in the cas...
Thu Oct 26, 2017 9:08 pm
Forum: Trends in The Periodic Table
Topic: d-block elements
Replies: 1
Views: 184

### d-block elements

During the lecture Lavelle stated that d-block elements form cations with different oxidation numbers. My question is how do you find the oxidation numbers and what does it mean?
Fri Oct 20, 2017 8:57 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: s-, p-, d-, f- Orbitals [ENDORSED]
Replies: 3
Views: 251

### s-, p-, d-, f- Orbitals[ENDORSED]

During the lecture how did Professor Lavelle get 1s^2 , 2s^2 , 2p sub x ^1 , 2p sub y ^1 ? I understand on the periodic table it gives the max like 2p for Carbon, but how did he get 1s, 2s ? And how do you know how many electrons are in each s p d f orbitals? How do you determine if they are paralle...
Fri Oct 20, 2017 8:52 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: s-,p-, d-, and f- orbitals
Replies: 7
Views: 423

### Re: s-,p-, d-, and f- orbitals

So what does m sub l quantum numbers tell you? Does:
0 (s-)
-1, 0, 1 (p-)
-2, -1, 0, 1, 2 (d-)
-3, -2, -1, 0, 1, 2, 3 (f-)

tell you the number of electrons that each subshell can hold? I don't get what the numbers mean. Sorry I am super confused and I have never learned this in high school.
Fri Oct 20, 2017 8:38 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Uncertainty of Velocity [ENDORSED]
Replies: 2
Views: 233

### Uncertainty of Velocity[ENDORSED]

Why do we have to find the uncertainty in velocity after we find the uncertainty in momentum (delta p), like how Professor Lavelle did the second step on the example he showed in class after he found delta p? What does the uncertainty of velocity tell us?
Fri Oct 20, 2017 8:36 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Understadning Heisenberg Indeterminacy Equation
Replies: 6
Views: 385

### Understadning Heisenberg Indeterminacy Equation

What is the purpose of the Heisenberg Indeterminacy equation? Is it used to figure out the position of the electron in order to understand its structure more? Can someone please explain this more to me? I am a little confused.
Fri Oct 13, 2017 10:26 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Question about 1.17 [ENDORSED]
Replies: 3
Views: 348

### Question about 1.17[ENDORSED]

During the lecture, Lavelle showed us (En=-hR/(n^2), the other form of the Rydberg equation. Can I use this equation instead of the Z-indpendent Rydberg equation to solve this problem? The problem is: The energy levels of hydrogenlike one-electron ions of atomic number Z differ from those of hydroge...
Fri Oct 13, 2017 9:49 pm
Forum: Photoelectric Effect
Topic: Difference between Photoelectric effect and Atomic Spectra [ENDORSED]
Replies: 2
Views: 141

### Difference between Photoelectric effect and Atomic Spectra[ENDORSED]

Can someone please tell me what the difference between the photoelectric effect and the atomic spectra? I am confused and I need to know their difference so I can comprehend the bigger picture of the topic and understand the use of the equations more.
Fri Oct 13, 2017 9:47 pm
Forum: Properties of Electrons
Topic: Wave Properties of Electrons
Replies: 3
Views: 222

### Re: Wave Properties of Electrons

In addition, the purpose of diffraction in the experiment is to prove/ show that electrons and thus all matter have wave-like properties since diffraction is produced by the interaction between destructive and constructive waves. I hope this helps you understand more about the topic!
Fri Oct 13, 2017 9:40 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: H-Atom Equation
Replies: 3
Views: 192

### H-Atom Equation

Why is there a negative sign in E(N)= -hR/n^2 aka the equation for H-atoms? Does the negative sign mean energy is lost when it goes from a higher state back to ground level? But for problems where the electron goes from ground state to a higher/ excited state (like from n=1 to n=2), do we still use ...
Tue Oct 03, 2017 8:52 pm
Forum: Limiting Reactant Calculations
Topic: Help with M9
Replies: 5
Views: 377

### Re: Help with M9

Hmmm... I only took high school chemistry so I don't really know/ remember what spectator ions are. Can you please expand that for me please? :)
Tue Oct 03, 2017 11:28 am
Forum: Limiting Reactant Calculations
Topic: Help with M9
Replies: 5
Views: 377

### Help with M9

Why is the Na canceled out in the equation (according to the solutions manual)? There is a similar questions posted previously but the answer was not very detailed and I am still confused.

Thanks for your help in advance! :)

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