Search found 43 matches

by harperlacroix1a
Fri Dec 07, 2018 9:36 pm
Forum: Conjugate Acids & Bases
Topic: Oxoacids
Replies: 2
Views: 118

Oxoacids

Can someone explain to me what an oxoacid is, and how it differs from a normal acid?
by harperlacroix1a
Tue Dec 04, 2018 4:31 pm
Forum: Electronegativity
Topic: Trend of Electronegativity
Replies: 12
Views: 464

Re: Trend of Electronegativity

The trends are the same. They increase up a group and across a period. It usually helps me to draw a diagonal line up and across the periodic table to remind myself of this trend during tests!
by harperlacroix1a
Tue Dec 04, 2018 4:29 pm
Forum: Sigma & Pi Bonds
Topic: Rotating Bond?
Replies: 4
Views: 218

Re: Rotating Bond?

Sigma bonds are allowed to rotate because the electron distribution does not change and bond strength stays the same due to the fact that electron density in sigma bonds are along the axis
by harperlacroix1a
Tue Dec 04, 2018 4:27 pm
Forum: Naming
Topic: Naming using Prefixes
Replies: 1
Views: 42

Naming using Prefixes

How do you know which prefix to use? Bi vs Bis, Tri vs Tris, Tetra vs Tetrakis
by harperlacroix1a
Fri Nov 30, 2018 2:19 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Number
Replies: 10
Views: 142

Re: Coordination Number

the coordination number is the number of atoms/ions that surround the central atom and you find it by calculating the charge
by harperlacroix1a
Mon Nov 26, 2018 8:21 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: Intermolecular forces and melting/boiling points
Replies: 4
Views: 97

Re: Intermolecular forces and melting/boiling points

Dipole Dipole is molecules having a concentration of charge in a certain area due to polarity, which allows for greater attraction with another molecule that has its charges concentrated in certain areas. Hydrogen bonding is just super strong Dipole Dipole because of the Hydrogen with very electron...
by harperlacroix1a
Mon Nov 26, 2018 6:43 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: Intermolecular forces and melting/boiling points
Replies: 4
Views: 97

Intermolecular forces and melting/boiling points

How does hydrogen bonding, LDF forces, and dipole dipole interactions affect the melting and boiling points of molecules? does it have to do with the electronegativity or strong/weakness of the force?
by harperlacroix1a
Sun Nov 25, 2018 7:39 pm
Forum: Bond Lengths & Energies
Topic: Isolobal Principle
Replies: 1
Views: 55

Isolobal Principle

Can someone explain the isolobal principle/analogy to me? In problem 3.101 of the 6th edition, they replace bonds of C-H in the benzene structure with nitrogen but I'm confused as to why this is possible or why it happens.
by harperlacroix1a
Fri Nov 23, 2018 10:33 pm
Forum: Dipole Moments
Topic: Polarity
Replies: 9
Views: 132

Re: Polarity

Since oxygen is more electronegative, it pull on the molecule making it polar
by harperlacroix1a
Fri Nov 23, 2018 10:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 3
Replies: 10
Views: 214

Re: Test 3

It covers all of chapter 4 and the end of chapter three as outlined on his website
by harperlacroix1a
Fri Nov 23, 2018 10:30 pm
Forum: Hybridization
Topic: reason for hybridization
Replies: 9
Views: 173

Re: reason for hybridization

It exists because hybridized orbitals are lower in energy which results in a more stable compound
by harperlacroix1a
Sun Nov 18, 2018 9:47 pm
Forum: Quantum Numbers and The H-Atom
Topic: Degeneracy
Replies: 8
Views: 370

Re: Degeneracy

Degeneracy is basically the levels of orbitals with the same energy, signified by the principle quantum number
by harperlacroix1a
Sun Nov 18, 2018 9:46 pm
Forum: Resonance Structures
Topic: Radicals
Replies: 11
Views: 342

Re: Radicals

A radical has an unpaired valence electron on an atom
by harperlacroix1a
Thu Nov 15, 2018 1:59 pm
Forum: Octet Exceptions
Topic: The center atom
Replies: 20
Views: 517

Re: The center atom

The central atom is usually the one with the lowest ionization energy
by harperlacroix1a
Thu Nov 15, 2018 1:58 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 10
Views: 377

Formal Charge

When determining molecular structures, is having the formal charge be 0 or having a complete octet more important?
by harperlacroix1a
Thu Nov 15, 2018 1:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Trigonal Shapes
Replies: 4
Views: 54

Trigonal Shapes

What is the difference between trigonal planar and trigonal pyramidal? why are the bond angles in trigonal planar 120 degrees but the angles in trigonal pyramidal differ?
by harperlacroix1a
Mon Nov 12, 2018 8:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecules with Lone Pairs
Replies: 1
Views: 44

Molecules with Lone Pairs

For problem 4.1 in the 6th edition, it asks whether there can be lone pairs on the central atom of the ball and stick models of the atom. part (a) models three atoms with an angle of 120 degrees and the second is a linear model with an angle of 180 degrees. how does the degree decide how many lone p...
by harperlacroix1a
Fri Nov 09, 2018 12:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Tetrahedral molecules
Replies: 4
Views: 74

Re: Tetrahedral molecules

Yes, the way he spoke about it in lecture today was that since it is 3d, the tetrahedral molecules have bond angles of 109.5 degrees
by harperlacroix1a
Fri Nov 09, 2018 12:46 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Different Shapes
Replies: 4
Views: 83

Re: Different Shapes

In today's lecture (11/9) we went over linear, trigonal planar, and tetrahedral.
by harperlacroix1a
Fri Nov 09, 2018 12:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Trigonal Planar
Replies: 8
Views: 112

Re: Trigonal Planar

It would be 3d
by harperlacroix1a
Sun Nov 04, 2018 4:44 pm
Forum: Lewis Structures
Topic: Problem 3.57 6th edition
Replies: 1
Views: 37

Problem 3.57 6th edition

This asks to draw the lewis and appropiate resonance structures for a hydrogen sulfite ion. Why does the hydrogen bond to one of the oxygens, instead of just attaching to the sulfer?
by harperlacroix1a
Sun Nov 04, 2018 4:33 pm
Forum: Lewis Structures
Topic: Expanded Octets
Replies: 2
Views: 43

Expanded Octets

Why can some elements have expanded octects? for example, problem 3.57 in the 6th edition asks for lewis structure of a sulfite ion (SO3)2- and in the expanded octet, sulfur has 10 electrons attached to it. why can this happen and when do i know that a compound has an expanded octet?
by harperlacroix1a
Sun Nov 04, 2018 4:10 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical Formulas with Masses
Replies: 3
Views: 124

Re: Empirical Formulas with Masses

You would first need to find the mass percentage of the element, and then assume that the mass percent is equal to grams and that you have 100 g of the substance.
by harperlacroix1a
Sun Nov 04, 2018 4:08 pm
Forum: Trends in The Periodic Table
Topic: Ionization Energies
Replies: 2
Views: 53

Ionization Energies

Do we need to know how to calculate the exact ionization energies for the midterm? If so, how do we do it?
by harperlacroix1a
Sun Nov 04, 2018 4:07 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 7
Views: 175

Formal Charge

Should the formal charge for a Lewis structure ever not be equal to zero? Is something for sure wrong with the structure if the formal charge not equal to zero?
by harperlacroix1a
Sat Nov 03, 2018 9:07 am
Forum: Lewis Structures
Topic: Do brackets go over cations or anions or either or both?
Replies: 3
Views: 77

Re: Do brackets go over cations or anions or either or both?

I believe you put them on both the cation and anion to show how they are charged. []- and []+
by harperlacroix1a
Mon Oct 29, 2018 12:26 pm
Forum: Lewis Structures
Topic: 3.33 Lewis Structure for NOF
Replies: 1
Views: 65

3.33 Lewis Structure for NOF

in problem 33 in the 6th edition, it asks for the lewis structure of NOF. the solutions manual shows a double bond between O and N, with N having a lone pair, O having 2 lone pairs, and F having 3 lone pairs and a bond with N. Why couldn't you have two double bonds between N and O/F with O and F hav...
by harperlacroix1a
Sun Oct 28, 2018 4:00 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 8
Views: 139

Re: Atomic Radius

I doubt we will be expected to know exact values. I think just knowing the trends and which radii is larger is sufficient
by harperlacroix1a
Wed Oct 24, 2018 11:46 am
Forum: Trends in The Periodic Table
Topic: Test 2
Replies: 3
Views: 99

Re: Test 2

test 2 only covers material up to last friday's lecture, so it includes nothing about periodic table trends
by harperlacroix1a
Tue Oct 23, 2018 1:06 am
Forum: Properties of Light
Topic: Test 2 Outline 2 Question About Electron Transition
Replies: 1
Views: 61

Re: Test 2 Outline 2 Question About Electron Transition

Basically electrons in both atoms and molecules can be excited to higher energy states (n=1,2 etc) so when they emit electromagnetic radiation, it gives detail to the spectroscopy
by harperlacroix1a
Sun Oct 21, 2018 7:17 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: test #2
Replies: 4
Views: 65

Re: test #2

My TA mentioned that it would 40 points. It is going to be less questions apparently, but more in depth
by harperlacroix1a
Fri Oct 19, 2018 8:53 am
Forum: Einstein Equation
Topic: Numbers to memorize
Replies: 24
Views: 704

Re: Numbers to memorize

Our first test had a formula sheet on the front. I assume that is the same sheet we will be given all quarter
by harperlacroix1a
Thu Oct 18, 2018 11:47 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Balmer and Lyman Series
Replies: 2
Views: 46

Balmer and Lyman Series

Can someone explain what the Balmer and Lyman series are? I know that the Lyman series corresponds to UV light and the Balmer series corresponds to visible light, but where is this relevant and what does this mean?
by harperlacroix1a
Sun Oct 14, 2018 8:06 pm
Forum: Properties of Light
Topic: C=Wavelength*Frequency
Replies: 11
Views: 215

Re: C=Wavelength*Frequency

C represents the speed of light
by harperlacroix1a
Sun Oct 14, 2018 8:05 pm
Forum: Properties of Light
Topic: Chapters 1 and 2 logisitcs
Replies: 3
Views: 85

Re: Chapters 1 and 2 logisitcs

Homework due this week is chapter's 1 and 2 I believe. We definitely have not started a new chapter since Friday, so homework should be from 2 especially, and 1 if you need practice. Every TA is different, but if you are doing current material, they should not mind.
by harperlacroix1a
Mon Oct 08, 2018 7:07 pm
Forum: Empirical & Molecular Formulas
Topic: Mass Percent Composition
Replies: 7
Views: 313

Re: Mass Percent Composition

These problems should always add up to 100%. If not, it might be a trick question or you are mis calculating.
by harperlacroix1a
Sun Oct 07, 2018 4:10 pm
Forum: SI Units, Unit Conversions
Topic: Formula Sheet?
Replies: 6
Views: 139

Re: Formula Sheet?

There is a formula sheet uploaded onto Lavelle's website, however, it doesn't have much to help with the fundamentals section. He will probably still give it to us, but not sure how useful it will be. The only thing to memorize for this test would probably be the SI unit conversions.
by harperlacroix1a
Thu Oct 04, 2018 4:27 pm
Forum: SI Units, Unit Conversions
Topic: Homework Questions [ENDORSED]
Replies: 14
Views: 250

Re: Homework Questions [ENDORSED]

Will homework always be due on Friday during the lecture? Or will we switch to turning in HW to the TA during our discussion period? Just wondering because what if we have to turn in homework that wasn't covered yet (in case our lecture is after our discussion period). Homework will be due, startin...
by harperlacroix1a
Thu Oct 04, 2018 4:14 pm
Forum: Balancing Chemical Reactions
Topic: H.11 part 2 balancing tricks?
Replies: 2
Views: 74

Re: H.11 part 2 balancing tricks?

I think that balancing by jumping back and forth is the best way to do it. I always like to leave oxygen last because sometimes things get weird with the oxygen (and theres usually a lot of oxygen in complicated equations), but other than that, I can't think of any good 'tricks'
by harperlacroix1a
Thu Oct 04, 2018 1:26 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molecules vs Formula Units? E21
Replies: 2
Views: 62

Molecules vs Formula Units? E21

In the 6th Edition, questions E21 asks for the amount (in moles) of molecules and formula units. What is the difference between these when calculating?
by harperlacroix1a
Wed Oct 03, 2018 11:51 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Question E1(6th Edition)
Replies: 7
Views: 197

Re: Question E1(6th Edition)

I began this problem by multiplying 1.00 mol of Ag by Avogadro's number to get 6.022x10^23 atoms of Ag. Then I multiplied that by 2(144 pm)--144 pm is the radius of the atom, so to get the total length of the atom you have to double it. The end result was 1.73x10^26 pm, which is equal to 1.73x10^11...

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