Search found 52 matches

Sat Dec 12, 2020 9:41 am
Forum: Determining Molecular Shape (VSEPR)
Topic: heme complex [ENDORSED]
Replies: 1
Views: 299

heme complex[ENDORSED]

is a heme complex square planar or tetrahedral?
Tue Dec 08, 2020 2:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: shape
Replies: 1
Views: 7

shape

Draw the Lewis structure and give the approximate bond angles of (d) N2H4. Why can't there be a triple bond between the N atoms?
Mon Dec 07, 2020 4:09 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: coord number and oxidation number
Replies: 3
Views: 30

coord number and oxidation number

How do we determine the oxidation and coordination number of a compound?
Mon Dec 07, 2020 4:07 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Dentisisty
Replies: 1
Views: 8

Dentisisty

How can we tell the dentisity of a compound without drawing it out?
Fri Dec 04, 2020 6:37 pm
Forum: Amphoteric Compounds
Topic: 6A 17
Replies: 4
Views: 47

6A 17

how would you figure out the answers for 6A 17 "6A.17 State whether the following oxides are acidic, basic, or amphoteric: (a) BaO; (b) SO3; (c) As2O3; (d) Bi2O3." what would the explanation be for each?
Fri Dec 04, 2020 1:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: difference
Replies: 4
Views: 33

difference

how can we tell the difference between trigonal planar and t-shaped?
Fri Dec 04, 2020 1:07 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: calculating
Replies: 2
Views: 35

calculating

is the H3O concentration always the same when calculating pH or does the problem give us a specific number?
Thu Dec 03, 2020 2:43 pm
Forum: *Molecular Orbital Theory Applied To Transition Metals
Topic: planes
Replies: 4
Views: 59

planes

how would you know if atoms in a compound are in the same plane or not?
Mon Nov 30, 2020 11:40 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: textbook 2.57
Replies: 1
Views: 36

textbook 2.57

Hi, I cannot find the answer for question 2.57 (2.57 Acetonitrile, CH3CN, is used as a solvent in the pharmaceu- tical industry. Describe the structure of the CH3CN molecule in terms of hybrid orbitals, bond angles, and s- and p-bonds. The N atom is a terminal atom.) in the textbook. Does anyone kno...
Mon Nov 30, 2020 9:34 pm
Forum: Hybridization
Topic: identification
Replies: 5
Views: 66

identification

how do you Identify the hybrid orbitals for BrF3?
Mon Nov 30, 2020 9:32 pm
Forum: Hybridization
Topic: pcl3
Replies: 8
Views: 48

pcl3

why is the hybridization of PCl3 sp^3 and not sp^2?
Mon Nov 23, 2020 10:31 pm
Forum: Electronegativity
Topic: determining electronegativity
Replies: 31
Views: 253

Re: determining electronegativity

I just follow the periodic table trend. Electronegativity increases from left right and down up!
Mon Nov 23, 2020 10:27 pm
Forum: Hybridization
Topic: e density
Replies: 30
Views: 132

e density

is every bond and lone pair considered a region of electron density?
Mon Nov 23, 2020 10:25 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: memorization
Replies: 12
Views: 114

memorization

hi,
Is there an easy way to memorize the shapes and their names? any tips?
Thu Nov 19, 2020 10:52 pm
Forum: Sigma & Pi Bonds
Topic: Triple bond?
Replies: 21
Views: 165

Re: Triple bond?

a triple bond has one sigma and 2 pi bonds
Thu Nov 19, 2020 10:50 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 3d and 4s
Replies: 9
Views: 71

Re: 3d and 4s

basically they just wrote 3d^5 instead of 3d^3 4S^2 because the d orbital is more stable when its either half filled or completely filled
Thu Nov 19, 2020 5:59 pm
Forum: Trends in The Periodic Table
Replies: 9
Views: 61

why is the atomic radius of Br- larger than Na?
Thu Nov 19, 2020 2:56 pm
Forum: Dipole Moments
Topic: Pressures and Points
Replies: 4
Views: 47

Pressures and Points

How do we identify stronger melting and boiling points? Also what is vapor pressure and how can it be higher? for example, why is the vapor pressure of diethyl ether (C2H5OC2H5) is greater than that of water.
Thu Nov 19, 2020 2:48 pm
Forum: Bond Lengths & Energies
Topic: electron repulsion
Replies: 15
Views: 131

electron repulsion

Is there electron repulsion in every atom with a lone pair?
Fri Nov 13, 2020 11:15 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: is it polar
Replies: 6
Views: 78

is it polar

Hi,
how do we assign charges for dipole moments and how can we tell if a molecule is polar or not?
Thu Nov 12, 2020 11:42 am
Forum: Formal Charge and Oxidation Numbers
Topic: charge of atom
Replies: 2
Views: 41

charge of atom

how do we find the charge of an atom? is there a way to tell the charge of an atom from its magnetic spin? do the arrows tell us anything about the atoms charge?
Wed Nov 11, 2020 9:56 pm
Forum: Dipole Moments
Topic: induced dipole vs dipole
Replies: 11
Views: 42

induced dipole vs dipole

What is the difference between induced dipole-induced dipole and dipole-dipole and how can we tell the difference?
Wed Nov 11, 2020 9:54 pm
Forum: Ionic & Covalent Bonds
Topic: distinguishing bonds
Replies: 2
Views: 13

distinguishing bonds

What is the fastest way to distinguish between ionic and covalent bonds?
Wed Nov 11, 2020 9:53 pm
Forum: Bond Lengths & Energies
Topic: boiling point and IMS
Replies: 5
Views: 35

boiling point and IMS

What is the relationship between boiling points and Intermolecular forces?
Wed Nov 11, 2020 9:51 pm
Forum: Dipole Moments
Topic: partial dipole
Replies: 2
Views: 7

partial dipole

how do we know if a bond has partial dipole moments?
Tue Nov 10, 2020 9:30 pm
Forum: Bond Lengths & Energies
Topic: electron affinity
Replies: 2
Views: 25

electron affinity

why does the electron has a lower energy when it occupies one of the atom’s orbitals?
Mon Nov 02, 2020 9:59 pm
Forum: Lewis Structures
Topic: charge by square bracket
Replies: 8
Views: 61

charge by square bracket

HI,
What are the charges outside of the square brackets that the lewis structure is in? For example, Dr, Lavelle, put a - outside of the lewis structure for NO3 in his lecture today (11/02).
Mon Nov 02, 2020 9:55 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Scores
Replies: 28
Views: 268

Re: Midterm Scores

Someone mentioned that Dr. Lavelle mentioned in his office hours that grades will be posted on Thursday!
Mon Nov 02, 2020 9:54 pm
Forum: Properties of Light
Topic: Wavelenght
Replies: 17
Views: 110

Re: Wavelenght

Gamma rays have the shortest wavelength and the highest frequency. On the other hand, Radio waves have the longest wavelengths=lowest frequency.
Mon Nov 02, 2020 9:51 pm
Forum: Lewis Structures
Topic: sides
Replies: 12
Views: 125

sides

Hi,
Let's say for NO3, does it matter what three sides we put O around N when creating the Lewis Structure? or could it be any side?
Mon Nov 02, 2020 9:49 pm
Forum: Trends in The Periodic Table
Topic: # of electrons
Replies: 23
Views: 118

# of electrons

Hi,
how do we count the number of electrons each element has?
Thu Oct 29, 2020 4:24 pm
Forum: Einstein Equation
Topic: energy of photon
Replies: 7
Views: 55

energy of photon

Can we use E=hv to find the energy of a photon or do we need to use the E= work function + KE to find it?
Wed Oct 28, 2020 10:54 am
Forum: SI Units, Unit Conversions
Topic: picometer conversion
Replies: 13
Views: 137

Re: picometer conversion

always remember that when you want to go from a higher unit to a lower unit you multiply so m to pm is x 10^12, and when you go from lower to higher you divide so pm to m is x 10^-12
Wed Oct 28, 2020 10:51 am
Forum: *Shrodinger Equation
Topic: Sapling week 2/3
Replies: 12
Views: 148

Re: Sapling week 2/3

for the first part, you regimen all the information needed to solve the equation using the uncertainty equation, just use the electron mass and don't forget to convert angstroms to m! for the second one make sure you convert the molar mass of helium from g/mol to kg/atoms using avogadro's then solve...
Tue Oct 27, 2020 7:31 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: E. 23 b
Replies: 3
Views: 36

E. 23 b

why don't we divide by Avogadro's to get moles for b in:

E.23 Calculate the amount (in moles) of (a) Cu21 ions in 3.00 g of CuBr2; (b) SO3 molecules in 7.00 3 102 mg of SO3; (c) F2 ions in 25.2 kg of UF6; (d) H2O in 2.00 g of Na2CO3?10H2O.
Tue Oct 27, 2020 7:00 pm
Forum: Photoelectric Effect
Topic: vacuum
Replies: 3
Views: 46

vacuum

Why does photoelectric effect have to be done under a vacuum?
Wed Oct 21, 2020 9:43 pm
Forum: Photoelectric Effect
Topic: Application
Replies: 5
Views: 44

Application

does the photoelectric effect only apply to metal surfaces?
Wed Oct 21, 2020 9:41 pm
Forum: Properties of Electrons
Topic: intensity vs energy
Replies: 29
Views: 247

intensity vs energy

can some explain this true or false question please with the answer:

An increase in intensity means an increase in energy
Wed Oct 21, 2020 9:38 pm
Forum: Properties of Light
Topic: wave vs particle
Replies: 3
Views: 41

wave vs particle

what are the differences between properties of waves and particles? any distinct differences that would immediately set them apart?
Tue Oct 20, 2020 10:42 pm
Forum: Properties of Electrons
Topic: 1A.1 part a
Replies: 4
Views: 61

1A.1 part a

Can someone explain the answer for part A of 1A.1 for the textbook problem: 1A.1 At the time that J. J. Thomson conducted his experiments on cathode rays, the nature of the electron was in doubt. Some considered it to be a form of radiation, like light; others believed the electron to be a particle....
Mon Oct 19, 2020 11:44 am
Forum: Properties of Light
Topic: calculating photons
Replies: 4
Views: 24

calculating photons

how do you calculate the number of photons when given wavelength and energy?
Mon Oct 12, 2020 10:46 pm
Forum: Properties of Electrons
Replies: 2
Views: 22

how do you calculate the energy per photon of ultraviolet radiation?
Mon Oct 12, 2020 10:17 pm
Forum: Properties of Light
Topic: Regions
Replies: 2
Views: 25

Regions

In the lecture posted today, Dr. Lavelle mentioned the UV region (29.50). What is that, what other regions are there, and how can we tell the difference?
Mon Oct 12, 2020 9:42 pm
Forum: Properties of Light
Topic: classical mechanic
Replies: 5
Views: 51

classical mechanic

does F=MA only apply to classical mechanics?
Mon Oct 12, 2020 9:35 pm
Forum: Empirical & Molecular Formulas
Topic: Finding Empirical Formula
Replies: 10
Views: 100

Re: Finding Empirical Formula

since empirical formulas require whole numbers, by multiplying 1.33 by 3, he gets to the closest whole number to use in the formula
Mon Oct 12, 2020 9:32 pm
Forum: Balancing Chemical Reactions
Topic: Balancing equations.
Replies: 35
Views: 733

Re: Balancing equations.

What I always do is that I count and balance. from the left. So I look at the first element from the left, make sure its balanced on both sides, then move on to the next elements. And when I'm done with that I just make sure that all my coefficients are whole numbers, then I just do a quick check on...
Mon Oct 12, 2020 4:43 pm
Forum: Properties of Light
Topic: video modules
Replies: 10
Views: 95

video modules

Are the "Wave properties of light, classical v quantum mechanics, and photon properties of light" video modules recommended for better understanding of the quantum world?
Mon Oct 05, 2020 12:28 pm
Forum: Balancing Chemical Reactions
Topic: Delta Over Reaction Arrow
Replies: 2
Views: 198

Re: Delta Over Reaction Arrow

hi,
delta over the arrow means that energy in the form of heat is being added to the reaction!
Mon Oct 05, 2020 12:25 pm
Forum: Molarity, Solutions, Dilutions
Replies: 14
Views: 145

hi,
it's easier to use 100g because you can just take the percent out of 100 instead of having to calculate and find the exact. it just makes it easier to calculate basically.
Mon Oct 05, 2020 12:22 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Replies: 31
Views: 363

Hi,
is there a specific way to know when exactly we need to use Avogadro's #? like key words or concepts that always require us to use it?
Mon Oct 05, 2020 12:19 pm
Forum: Balancing Chemical Reactions
Topic: Stoichiometric Coefficients
Replies: 20
Views: 147

Re: Stoichiometric Coefficients

hiii,
I would say always check and make sure it's balanced, even if other questions you've answered have been balanced always check. You don't want to solve a whole problem then have to redo it cause you didn't check and balance it in the beginning
Mon Oct 05, 2020 12:17 pm
Forum: Molarity, Solutions, Dilutions
Topic: dilution equation
Replies: 6
Views: 59

dilution equation

Hi,
if the problem gives us the initial volume in mL and we find the final volume in L, do we convert it to mL for our final answer or does it not matter? do our labels always have to match what the initial problem already gave us?