## Search found 45 matches

Wed Jun 13, 2018 12:38 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Homework 4.13
Replies: 2
Views: 243

### Homework 4.13

The question asks you to draw the shape of I3-. So I made the shape and saw that it was linear however the central atom had 6 lone pairs. Since the atom had lone pairs i figured that the shape would no longer be linear and that the shape would be bent. But the answer says linear with bond angles of ...
Tue Jun 12, 2018 11:35 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Determining Shapes [ENDORSED]
Replies: 1
Views: 250

### Determining Shapes[ENDORSED]

After the review session today I have come to learn that I am more confused about shapes than i thought i was. For starters, I understand the linear shape and I understand that when there is a lone pair the bond angle is less than 180. However, when it comes to the bent shape and the trigonal planar...
Mon Jun 11, 2018 8:12 pm
Forum: Bronsted Acids & Bases
Topic: Net ionic equations
Replies: 1
Views: 338

### Net ionic equations

On question 12.9, it asks you to identify which reaction can be a reaction between a Bronsted acid and base, and it says it may be useful to write the net ionic equation. Can anyone tell me what a net ionic equation is and how i might make one?
Mon Jun 11, 2018 5:23 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Lowest Energy/Stable
Replies: 2
Views: 233

### Lowest Energy/Stable

On test 3, a lot of the questions asked you to draw the lewis structure that had the lowest energy or the lewis structure that is most stable. Can most stable and lowest energy be used to mean the same thing? Also, would you determine that lowest energy/most stable would be when the formal charges a...
Mon Jun 11, 2018 12:29 am
Forum: Dipole Moments
Topic: Homework Question 4.25
Replies: 2
Views: 303

### Re: Homework Question 4.25

A nonpolar molecule must have zero must have zero electric dipole moment which is possible if the dipole moments cancel. In a polar bond the dipole moments do not cancel.
Mon Jun 11, 2018 12:25 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Final [ENDORSED]
Replies: 5
Views: 376

### Re: Final[ENDORSED]

There were a lot of shapes given in the book. Are we responsible to know every shape, or only the ones regarded in class? Just curious as in what I should put specific interest in while studying for the final
Mon Jun 11, 2018 12:22 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Atoms in a Plane
Replies: 4
Views: 335

### Re: Atoms in a Plane

How do we know when atoms are not in the same plane, and how would we express that these atoms are in different planes. Im assuming that they would be in different planes with the inclusion of a sigma bond which can rotate.
Mon Jun 11, 2018 12:20 am
Forum: Sigma & Pi Bonds
Topic: four bonds
Replies: 3
Views: 364

### Re: four bonds

I know that a single bond is a pi bond, a double bond is a sigma bond and a pi bond, and a triple bond is a sigma bond plus 2 pi bonds. Therefore, I would think that if a atom has four separate bonds all of these bonds would be 4 single bonds which would make four sigma bonds.
Wed Jun 06, 2018 10:58 pm
Forum: Lewis Acids & Bases
Topic: Ionic Equations and net ionic equation
Replies: 3
Views: 218

### Ionic Equations and net ionic equation

Under fundamentals J, homework question J.5, the question asks you to complete the overall equation and then write the complete ionic equation and then write the net ionic equation. I am not sure how to write any of the three equations. I am assuming that an ionic equation represents the ions writte...
Sun Jun 03, 2018 9:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: polar and nonpolar molecules
Replies: 5
Views: 338

### Re: polar and nonpolar molecules

How do we know which dipole moments cancel each other?
Sun Jun 03, 2018 9:09 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Ch 4 clarification
Replies: 2
Views: 238

### Re: Ch 4 clarification

Can anyone explain how we come to the conclusion of a hybrids that are sp3,sp2, etc? I am lost on how we determine which hybridization form a molecule would be.
Sun Jun 03, 2018 9:02 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Textbook 4.21 part d
Replies: 3
Views: 224

### Re: Textbook 4.21 part d

For clarification, since a bond angle of 109.5 refers to a tetrahedral, is a bond angle that is slightly less than 109.5 caused by lone pairs on the central atom? Do bond angles decrease due to lone pairs?
Thu May 31, 2018 9:24 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Homework 4.15 B
Replies: 1
Views: 209

### Homework 4.15 B

In problem number 4.15 b, we need to find the lewis structure and shape of TeCl4. When you calculate the number of valence electrons you get 34, so when you draw the lewis structure Te has four bonds and also has a lone pair. I thought the shape would be a tetrahedral however the answer is see saw. ...
Mon May 28, 2018 12:02 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond angle
Replies: 9
Views: 475

### Re: Bond angle

How do you calculate the degree of bond angle? Is this experimentally found?
Mon May 28, 2018 12:01 am
Forum: Determining Molecular Shape (VSEPR)
Topic: shapes
Replies: 3
Views: 269

### Re: shapes

You can find the shapes on page 109 of the textbook under section 4.1
Mon May 28, 2018 12:00 am
Forum: Dipole Moments
Topic: Dipole
Replies: 4
Views: 319

### Re: Dipole

When we draw the arrow, does the arrow point towards the atom that is more electronegative? for instance does the arrow point towards the partially negative atom?
Sun May 20, 2018 11:00 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Stable Lewis structures
Replies: 4
Views: 291

### Re: Stable Lewis structures

You first find the formal charge of each element in the compound, and then you compare the formal charges you have found for all structures and which ever structure has the most formal charges that are 0 or closest to 0 is the most stable structure out of what you are comparing. You can find the for...
Sun May 20, 2018 10:56 pm
Forum: Dipole Moments
Topic: the r power
Replies: 2
Views: 194

### Re: the r power

i think r represents the distance between the interacting particles
Sun May 20, 2018 10:52 pm
Forum: Ionic & Covalent Bonds
Topic: Test 3 [ENDORSED]
Replies: 7
Views: 549

### Re: Test 3[ENDORSED]

I'm pretty sure in this class we follow the policy that if it wasn't brought up in lecture we do not need to know it. I dont remember a lecture regarding how to name compunds
Sun May 20, 2018 5:27 pm
Forum: Ionic & Covalent Bonds
Topic: Octet rule
Replies: 17
Views: 1040

### Re: Octet rule

How do you know when atoms can break the octet rule? or which atoms can break the octet rule?
Sun May 20, 2018 5:18 pm
Forum: Electronegativity
Topic: Electronegativity difference
Replies: 3
Views: 315

### Re: Electronegativity difference

When there is a large difference between the electronegativity of atoms, we see that the atom with the larger electronegativity tends to pull the electrons in its direction. We can further kind if say that the larger electronegativity acts like an anion and the smaller one acts as a cation and this ...
Sun May 13, 2018 9:16 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Bonds
Replies: 3
Views: 196

### Re: Covalent Bonds

In class I remember that in covalent bonds nonmetals share the electrons to create this bond. I know that there is a specific diagonal that you can reference to distinguish between nonmetals and metals, however if the diagonal on the periodic table is not giving to you/not drawn out how could you re...
Sun May 13, 2018 9:10 pm
Forum: Ionic & Covalent Bonds
Topic: Resonance [ENDORSED]
Replies: 5
Views: 368

### Re: Resonance[ENDORSED]

How do we know when resonance is supposed to be applied? Would we be told that resonance is applicable in a certain problem or are we supposed to know that the molecule will have multiple forms as to which the electrons can be situated?
Sun May 13, 2018 9:08 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron configuration
Replies: 7
Views: 425

### Re: Electron configuration

Clarification question: so if you have a 3p^6 orbital you can fill the three orbitals first three electrons as spin down, then the next three as spin up as long as they are paired, it doesn't matter if you write spin up or spin down first?
Tue May 08, 2018 10:49 am
Forum: Molarity, Solutions, Dilutions
Topic: Test 1, Q1 [ENDORSED]
Replies: 4
Views: 482

### Re: Test 1, Q1[ENDORSED]

For part A of the question I got .054 M. This number is extremely different from the one above. If anyone knows how to do this problem could they please walk me through it. I found the molar mass of the salt and got 73.892 g/mol and I found that there are .054 mol of Li in the solution. I then divid...
Sun May 06, 2018 10:30 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Exceptions for Electron Configuration
Replies: 2
Views: 147

### Re: Exceptions for Electron Configuration

What i gathered from class is that copper and chromium are exceptions because in their ground state they are most stable when they have a half full (chromium) or a full (copper) 3d orbital. Chromium is more stable in its ground state as 3d^5 4s^1 as supposed to 3d^4 4s^2. Copper is more stable in it...
Sun May 06, 2018 10:25 pm
Forum: Trends in The Periodic Table
Topic: Trends to Know
Replies: 12
Views: 781

### Re: Trends to Know

I thought electron affinity was apart of chapter 2, I am just not positive if we specifically covered that in class.
Sun May 06, 2018 10:21 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic Bond formation
Replies: 5
Views: 353

### Re: Ionic Bond formation

if the energy required is 494 would we be expected to find this number or is the number given? I have no idea how to find that number
Mon Apr 30, 2018 8:19 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Homework 2.43 [ENDORSED]
Replies: 5
Views: 338

### Homework 2.43[ENDORSED]

The question asks you to solve for Tungsten by finding the electron configuration of this element. I thought the answer would be [Xe]5d^46s^2 however the answer is [Xe]4f^14 5d^4 6s^2. I am confused as to how the f orbital was brought into this answer. Any help would be great!!
Sun Apr 29, 2018 1:55 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: What does electron spin actually mean? [ENDORSED]
Replies: 9
Views: 1489

### Re: What does electron spin actually mean?[ENDORSED]

electrons behave like spinning spheres, almost like how a planet is rotating on its axis (textbook page 41). so if an electron is spin up it is spinning counterclockwise at a certain rate and if an electron is spin down it is spinning clockwise at the same rate.
Sun Apr 29, 2018 1:47 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: n, l, ml (relates to 2.19)
Replies: 2
Views: 178

### Re: n, l, ml (relates to 2.19)

From what i have gathered, atoms with the same value of n have the same energy and belong to a certain shell. The shell can be broken down into subshells which are groups of orbitals that have the sane value of l. l=0,1,2,...,n-1. So if the shell number is n=3, then the shell has subshells of 0,1,3-...
Sun Apr 29, 2018 1:36 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: understanding orbitals [ENDORSED]
Replies: 8
Views: 432

### Re: understanding orbitals[ENDORSED]

So in a p-orbital, when you are referring to the px,py,and pz nodal planes, how would you word the purpose of the planes in regards to the electrons position? would you say that there is a probability of the electron distribution along the px plane?
Sun Apr 22, 2018 11:48 pm
Forum: Significant Figures
Topic: Sig Fig Accuracy [ENDORSED]
Replies: 6
Views: 552

### Re: Sig Fig Accuracy[ENDORSED]

Today at the Step Up session i was told that sig figs will need to be accurate for test 2. With that being said i know the rules for multiplication and division, but adding and subtracting still confuses me. Does anyone have any simple easy to remember solutions while adding/subtracting with sig figs?
Sat Apr 21, 2018 10:21 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect Post Module [ENDORSED]
Replies: 2
Views: 167

### Re: Photoelectric Effect Post Module[ENDORSED]

Okay thank you! On B i was confused because i got the same answer as you but the system said i was incorrect. Thank you!
Sat Apr 21, 2018 9:31 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect Post Module [ENDORSED]
Replies: 2
Views: 167

### Photoelectric Effect Post Module[ENDORSED]

28. 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. Answer the following three questions. A. What is the kinetic energy of the ejected electron? D. 1.99 x 10-19 J I figures out that the kinetic energy is ...
Sat Apr 21, 2018 8:19 pm
Forum: Properties of Light
Topic: HW #1.7
Replies: 5
Views: 595

### Re: HW #1.7

I think i am a little confused too. I thought there were 10^-9 meters in a nanometer and 10^-12 meters in picometer.
Mon Apr 16, 2018 7:45 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Frequency if energy goes from n=2 to n=4
Replies: 6
Views: 270

### Re: Frequency if energy goes from n=2 to n=4

im not sure if i have this right, but if we know when we go down in energy levels a photon is emitted, if we go up in energy levels would something be absorbed or nothing be emitted at all?
Mon Apr 16, 2018 6:31 pm
Forum: Properties of Light
Topic: HW 1.15
Replies: 3
Views: 226

### Re: HW 1.15

Im stuck on this problem too, but to get it started i used the equation where c=v*lamda and rearranged the equation to solve for v(frequency). With v i know you can use the equation with Rydberg constant which is given by v=R{(1/n1^2)-(1/n2^2)}. However after I got that far i could not figure the re...
Sat Apr 14, 2018 10:04 pm
Forum: Properties of Light
Topic: Help on 1.9 [ENDORSED]
Replies: 4
Views: 248

### Re: Help on 1.9[ENDORSED]

I have filled in the majority of the chart through manipulating the equations and found the correct values but i am still confused on how to connect these values to the event. The events include a microwave, x-rays, uv rays, and reading and i am not sure how to pick which event for the data i have c...
Sat Apr 14, 2018 8:42 pm
Forum: Properties of Light
Topic: Units for wavelengths [ENDORSED]
Replies: 6
Views: 375

### Re: Units for wavelengths[ENDORSED]

wavelength is represented by the lamda symbol right?
Sat Apr 14, 2018 8:40 pm
Forum: Properties of Light
Topic: help on the question from Fridays lecture [ENDORSED]
Replies: 2
Views: 142

### Re: help on the question from Fridays lecture[ENDORSED]

In class I saw that Professor Lavelle kept during to the model which showed the light(energy of a photon) hits the metal to remove electrons. The equation is given as energy of photon-energy to remove electrons=energy in excess. Since the energy of a photon is given as E=h*v and c=lamda*v we can rea...
Sat Apr 14, 2018 8:31 pm
Forum: Limiting Reactant Calculations
Topic: Two limiting reactants?
Replies: 10
Views: 1297

### Re: Two limiting reactants?

So is the overall fact that there can't be two limiting reactants because only one reactant will be completely used and the other will be in excess? Multiple reactants cant be used up in a single reaction?
Sat Apr 14, 2018 8:29 pm
Forum: Molarity, Solutions, Dilutions
Topic: G17 [ENDORSED]
Replies: 1
Views: 72

### Re: G17[ENDORSED]

Hello, So when I did the problem I saw that what was given was 250mL and .20 M CuSO4. With those two factors we can rearrange the equation of molarity to be molarity*liters= the moles. From there, I found the moles of the problem and in one mole of CuSO4*5H20 there is 246.68 g/mol. Therefore the mol...
Mon Apr 09, 2018 10:21 pm
Forum: Limiting Reactant Calculations
Topic: What is the mass of AgCl produced?
Replies: 10
Views: 4857

### Re: What is the mass of AgCl produced?

After guessing a checking i found that the answer is 1.72 g AgCl. I found that the limiting reactant is C6H9Cl3 and that the moles of this compound is .004 moles. To get the answer 1.72, i saw that you have to triple .004 moles and then multiple that by the molar mass which is 143.32 g/mol. I am unc...
Mon Apr 09, 2018 10:01 pm
Forum: Limiting Reactant Calculations
Topic: What is the mass of AgCl produced?
Replies: 10
Views: 4857

### Re: What is the mass of AgCl produced?

According to the following equation, 0.750 g of C6H9Cl3 is mixed with 1.000 kg of AgNO3 in a flask of water. A white solid, AgCl, completely precipitates out. What is the mass of AgCl produced? This question is in the module on Limiting Reactant Calculations. I have followed the steps provided howev...

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