## Search found 31 matches

- Sun Jun 10, 2018 6:45 pm
- Forum: Lewis Structures
- Topic: Drawing Lewis Structures on the Final Exam
- Replies:
**5** - Views:
**386**

### Re: Drawing Lewis Structures on the Final Exam

I'm not sure if bond angles really matter for a lewis structure... I was told that they are important mostly for VSEPR, b/c that represents a 3D space.

- Sun Jun 10, 2018 6:41 pm
- Forum: Naming
- Topic: Coordination number
- Replies:
**10** - Views:
**830**

### Re: Coordination number

Just to add, coordination number typically applies to compounds with a transition metal as the central atom, so it isn't likely that you would encounter a double or triple bond in the first place.

- Sun Jun 10, 2018 6:40 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Drawing coordination compounds
- Replies:
**2** - Views:
**218**

### Drawing coordination compounds

Does anyone know if drawing coordination compounds will be a topic on the final? I know a couple topics regarding coordination compounds were taken out so I am just wondering. Thanks.

- Sat Jun 02, 2018 11:24 am
- Forum: Hybridization
- Topic: Textbook 4.37
- Replies:
**3** - Views:
**222**

### Re: Textbook 4.37

P has 4 areas of electron density because P has 3 bonding pairs AND a lone pair. Lone pairs are represented by both spin up and spin down.

so the answer is sp3 with the 3s orbital containing both a spin up and spin down, and the 3p orbital having 3 unpaired e-.

so the answer is sp3 with the 3s orbital containing both a spin up and spin down, and the 3p orbital having 3 unpaired e-.

- Sat Jun 02, 2018 11:18 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Naming shape
- Replies:
**7** - Views:
**459**

### Re: Naming shape

When a question asks for molecular shape, you have to take into account the number of areas of electron density, lone pairs, etc., not just the number of atoms.

- Sat Jun 02, 2018 10:33 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: coordination number vs. oxidation number [ENDORSED]
- Replies:
**4** - Views:
**617**

### Re: coordination number vs. oxidation number [ENDORSED]

I think coordination number is the number of immediate atoms surrounding a central atom whereas oxidation number is the number assigned to an atom to represent the # of electrons lost or gained

- Sun May 27, 2018 12:41 pm
- Forum: Hybridization
- Topic: Hybrid Orbitals
- Replies:
**4** - Views:
**279**

### Re: Hybrid Orbitals

How do you know when hybridization is necessary/ takes place?

- Sun May 27, 2018 12:38 pm
- Forum: Resonance Structures
- Topic: Clarifying wording
- Replies:
**2** - Views:
**339**

### Clarifying wording

Is being "more likely to contribute to a resonance structure" the same as being the best/ most stable resonance structure?

- Sun May 27, 2018 12:25 pm
- Forum: Bond Lengths & Energies
- Topic: 3.85 part b
- Replies:
**3** - Views:
**293**

### Re: 3.85 part b

When there is resonance, electrons are delocalized and so the bond length distribution is somewhere between the single and double bond in the structure.

- Wed May 16, 2018 11:29 am
- Forum: Octet Exceptions
- Topic: Concept of Exceptions
- Replies:
**4** - Views:
**393**

### Re: Concept of Exceptions

I think about it this way: s-orbitals can hold 2 e- p-orbitals can hold 6 e- so s and p together can hold 8e-, which is an octet. But starting from row 3 of the periodic table, there is a d-orbital, and d-orbitals can hold up to 10e-. So if an element has s, p, and d orbitals, the electrons in the d...

- Wed May 16, 2018 11:25 am
- Forum: Octet Exceptions
- Topic: Radicals [ENDORSED]
- Replies:
**6** - Views:
**550**

### Re: Radicals [ENDORSED]

Or if you look at the lewis structure an see an electron attached that is not in a pair, you can conclude that the structure is a radical.

- Wed May 16, 2018 11:23 am
- Forum: Ionic & Covalent Bonds
- Topic: Electron affinity [ENDORSED]
- Replies:
**6** - Views:
**421**

### Re: Electron affinity [ENDORSED]

I think the reason you are confused is because you have an incorrect definition of electron affinity. Since electron affinity is how much an element "wants" an electron, it only makes sense that the more an element wants an electron, the harder (greater energy) it will take to take an elec...

- Wed May 09, 2018 2:03 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Unicorn Practice Midterm #8
- Replies:
**3** - Views:
**426**

### Re: Unicorn Practice Midterm #8

I keep getting 10^-31 instead of 10^-32, can someone help me figure out where I went wrong?

I converted the g to kg and made sure I used the right units..

I converted the g to kg and made sure I used the right units..

- Wed May 09, 2018 1:56 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Ni3+
- Replies:
**3** - Views:
**4556**

### Re: Ni3+

Nevermind, I got it

- Wed May 09, 2018 1:53 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Ni3+
- Replies:
**3** - Views:
**4556**

### Ni3+

Hi,

Can someone explain to me why the electron configuration of Ni3+ is [Ar] 3d^7, without the 4s orbitals filled up?

Thanks

Can someone explain to me why the electron configuration of Ni3+ is [Ar] 3d^7, without the 4s orbitals filled up?

Thanks

- Wed May 09, 2018 11:32 am
- Forum: Trends in The Periodic Table
- Topic: Zeff HW 2.37
- Replies:
**2** - Views:
**223**

### Zeff HW 2.37

2.37 asks: True or False? Zeff for an electron in a p-orbital is lower than for an electron in an s-orbital in the same shell. The statement is true, but I'm confused because I thought that as you go across a group (which would have the same shell), Zeff increases. Can someone explain where I went w...

- Sun May 06, 2018 10:38 am
- Forum: *Particle in a Box
- Topic: Relationship to Schrodinger's Equation
- Replies:
**1** - Views:
**573**

### Relationship to Schrodinger's Equation

How does a particle in a box model Schrodinger's equation? In another post, it said that this model explains energy quantization since the box has infinitely high walls. Wouldn't there need to be a discrete amount of energy needed to pass the walls? Or does this model explain quantization in that th...

- Sun May 06, 2018 10:31 am
- Forum: *Shrodinger Equation
- Topic: Schrodinger's Equation & Orbitals
- Replies:
**3** - Views:
**333**

### Schrodinger's Equation & Orbitals

Can someone give me a basic rundown of how we use Schrondinger's equation to understand orbitals? I know we don't have to know the equation in depth but I am confused on the general relationship between the equation and orbitals.

- Sun May 06, 2018 10:28 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Switching 3d and 4s
- Replies:
**6** - Views:
**562**

### Switching 3d and 4s

Even though d has a higher energy than s, I was told that for some configurations you have to switch 3d to be in front of 4s. When is this the case?

- Wed Apr 25, 2018 7:56 pm
- Forum: Photoelectric Effect
- Topic: Calculating kinetic energy of an emitted electron [ENDORSED]
- Replies:
**3** - Views:
**478**

### Re: Calculating kinetic energy of an emitted electron [ENDORSED]

the mass of an electron is a constant (9.11x 10^-31 kg).

- Wed Apr 25, 2018 1:43 pm
- Forum: DeBroglie Equation
- Topic: Ek= 0 [ENDORSED]
- Replies:
**3** - Views:
**302**

### Ek= 0 [ENDORSED]

What are some situations where you have to set Ek to 0?

- Tue Apr 24, 2018 11:21 am
- Forum: DeBroglie Equation
- Topic: When to use DeBroglie or Ek equation
- Replies:
**7** - Views:
**465**

### Re: When to use DeBroglie or Ek equation

It all depends on what the question is asking. For example, if the question asks for the wavelength given mass and velocity, then you use the debroglie equation. if the question asks for KE or the maximum energy of electrons you use the Ek equation.

- Sat Apr 21, 2018 10:28 am
- Forum: Einstein Equation
- Topic: Different equations
- Replies:
**4** - Views:
**332**

### Re: Different equations

What I found helpful is realizing that in certain situations, the energy of the photon (E=hv) is equivalent to the work function. Instead of trying to figure out the work function, I simply use the Einstein equation. But this is only in particular cases.

- Sat Apr 21, 2018 10:22 am
- Forum: DeBroglie Equation
- Topic: Ch.1 #41 [ENDORSED]
- Replies:
**7** - Views:
**909**

### Re: Ch.1 #41 [ENDORSED]

Yes, you have to convert picometers to meters because m is the standard SI unit

- Wed Apr 18, 2018 11:31 am
- Forum: DeBroglie Equation
- Topic: HW 1.33
- Replies:
**12** - Views:
**653**

### HW 1.33

The velocity of an electron that is emitted from a metallic surface by a photon is 3.6 x 10^3 km/s. Part B says: No electrons are emitted from the surface of the metal until the frequency of the radiation reaches 2.50 x 10^16 Hz. How much energy is required to remove the electron from the metal surf...

- Wed Apr 11, 2018 7:49 pm
- Forum: Empirical & Molecular Formulas
- Topic: Empirical Formula
- Replies:
**3** - Views:
**390**

### Re: Empirical Formula

Once you balanced the equation, just find % mass of each element, convert mass to mol, divide each element's # moles by the smallest # mol,make sure you get whole numbers or otherwise multiply to get a whole number, and the numbers you get are the ratios for the empirical formula.

- Wed Apr 11, 2018 7:45 pm
- Forum: Limiting Reactant Calculations
- Topic: M.11
- Replies:
**8** - Views:
**968**

### Re: M.11

(b) take the number of moles of oxygen gas you initially have and subtract it by the moles of O2 used in the first equation to produce P4O6. you should have about .0405 mol O2 for the second equation. Use that number to calculate how many grams of P4O10 you would be able to produce in the second equ...

- Wed Apr 11, 2018 7:37 pm
- Forum: Properties of Light
- Topic: HW 1.3 [ENDORSED]
- Replies:
**12** - Views:
**759**

### HW 1.3 [ENDORSED]

Which of the following happens when the frequency of electromagnetic radiation decreases? Explain your reasoning. (a) The speed of the radiation decreases. (b) The wavelength of the radiation decreases. (c) The extent of the change in the electrical field at a given point decreases. (d) The energy o...

- Tue Apr 10, 2018 4:14 pm
- Forum: Limiting Reactant Calculations
- Topic: Mass of Products VS. Mass of Reactants- Class Assessment
- Replies:
**5** - Views:
**965**

### Re: Mass of Products VS. Mass of Reactants- Class Assessment

I think this question is just testing if you understand law of conservation of mass, so I think the answer should be no.

- Mon Apr 09, 2018 4:09 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing Equations With Rational Coefficients [ENDORSED]
- Replies:
**3** - Views:
**218**

### Re: Balancing Equations With Rational Coefficients [ENDORSED]

If he used a fraction w/ denominator 2, he probably multiplied the entire equation by 2 to create whole numbers afterwards

- Mon Apr 09, 2018 4:06 pm
- Forum: Limiting Reactant Calculations
- Topic: M19 - Combustion Analysis
- Replies:
**2** - Views:
**240**

### Re: M19 - Combustion Analysis

Find the moles of C, H, N, and O as these are the elements in caffeine. Then, divide by the smallest coefficient to get the EF. Divide the given molar mass of caffeine by the molar mass of the EF to get the ratio. multiply the resulting number by the EF to get the MF. To write the equation: MF of ca...