Search found 31 matches

by Nell Mitchell 1E
Sat Dec 08, 2018 7:08 pm
Forum: Naming
Topic: polydentate complexes?
Replies: 2
Views: 91

Re: polydentate complexes?

Polydentate ligands are those that can bind to one central atom in multiple places. The ligand must both be able to form the multiple coordinate covalent bonds, but also be configured in such a way that multiple can form simultaneously.
by Nell Mitchell 1E
Sat Dec 08, 2018 7:01 pm
Forum: Bronsted Acids & Bases
Topic: H vs OH
Replies: 3
Views: 119

Re: H vs OH

When comparing AOH and AH the difference is not that one is a stronger acid than another, but instead that you calculate their strengths differently. AH you look at bond length (longer bond=weaker bond=stronger acid). While for AOH you look at the electronegativity of the central atom (more electron...
by Nell Mitchell 1E
Sat Dec 08, 2018 6:53 pm
Forum: Amphoteric Compounds
Topic: Amphoteric
Replies: 4
Views: 240

Re: Amphoteric

Can something be an amphoteric compound, acting as an acid and a base, without being amphiprotic? Can it be an acid and base by donating and accepting lone pairs, not protons? Yes, Aluminum for example is amphoteric (can interact with acids and with bases) but it has no H+ to donate so it is not am...
by Nell Mitchell 1E
Sun Dec 02, 2018 7:48 pm
Forum: Lewis Acids & Bases
Topic: Lewis and Bronsted
Replies: 8
Views: 167

Re: Lewis and Bronsted

In addition to the different definitions, lewis classification is more general (all acids or bases can be classified as a lewis acid or base) while bronsted classification is more specified. Not all lewis acids/bases will also be bronsted acids/bases.
by Nell Mitchell 1E
Sun Dec 02, 2018 7:43 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Sphere
Replies: 4
Views: 81

Re: Coordination Sphere

Atoms or molecules that are not attached to the central atom of the coordination compound are outside of the coordination sphere. When written out in formula, anything outside the brackets is outside the coordination sphere.
by Nell Mitchell 1E
Sun Dec 02, 2018 4:02 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Strong acids
Replies: 2
Views: 69

Strong acids

What is the relationship between strong acids, bond length and electronegativity?
by Nell Mitchell 1E
Sun Nov 25, 2018 11:13 pm
Forum: Hybridization
Topic: reason for hybridization
Replies: 9
Views: 252

Re: reason for hybridization

Hybridization allows for the most stable (and most desirable) structure. When there are hybrid orbitals there are enough electrons to complete the necessary bonds - regardless of whether there is a suitable number of valence electrons. Carbon, for example, only has two valence electrons but hybridiz...
by Nell Mitchell 1E
Sun Nov 25, 2018 10:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sigma and Pi Bonds
Replies: 2
Views: 56

Sigma and Pi Bonds

I understand the rules regarding sigma and pi bonds - that sigma can rotate because the bond is on the axis but pi bonds can't because they're not on the axis - but I can't visualize how the pi bonds would break from rotation. Can someone explain this?
by Nell Mitchell 1E
Sun Nov 25, 2018 10:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond angle
Replies: 3
Views: 46

Re: Bond angle

Professor Lavelle made it clear that it is far more important to understand shape than to know specific bond angles. The only important concept to know is that when one of the regions of electron density is a lone pair instead of bonded, the other angles will be smaller and the angles around the lon...
by Nell Mitchell 1E
Sun Nov 18, 2018 11:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Position of Lone Pairs in H20
Replies: 3
Views: 90

Re: Position of Lone Pairs in H20

It's because shape is determined by number of regions of electron density and h2o has 4 electrons density regions (2 bonded, 2 lone pairs). When there's 4 regions of density the shape is trigonal pyramidal. But then because only two are bonded the other two do not contribute to the overall shape but...
by Nell Mitchell 1E
Sun Nov 18, 2018 11:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: vsper structures
Replies: 3
Views: 87

Re: vsper structures

The axial plane is the two electron densities that are 180 degrees from each other while the equatorial plane is 90 degrees from each of those densities and have varying degree separation from eachother depending on the number of electron densities. In the case of lone pairs being in those spots, a ...
by Nell Mitchell 1E
Sun Nov 18, 2018 11:40 pm
Forum: Dipole Moments
Topic: Identifying whether there is a dipole moment
Replies: 4
Views: 120

Re: Identifying whether there is a dipole moment

Electronegativity should only be included in term of trends, as in the electronegativity of one element relative to another. This is all you need to know for the dipole questions we've seen so far - no calculations necessary.
by Nell Mitchell 1E
Sun Nov 11, 2018 9:02 pm
Forum: Sigma & Pi Bonds
Topic: Difference in bonds
Replies: 2
Views: 77

Difference in bonds

What is the easiest way to remember the difference between pi and sigma bonds?
by Nell Mitchell 1E
Sun Nov 11, 2018 9:00 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 11
Views: 283

Re: Formal Charge

HIi! Can someone re-explain to me why the formal charge has to be zero? This is something that I keep forgetting. Thanks! Formal charge doesn't have to be zero, but the element will be most stable when formal charge is zero , so a molecule with all zero FCs will be most stable and therefore the bes...
by Nell Mitchell 1E
Sun Nov 11, 2018 8:52 pm
Forum: Electronegativity
Topic: Electronegativity
Replies: 3
Views: 92

Re: Electronegativity

Electronegativity measures the ability of an atom to attract electrons, while ionization energy measures the the amount of energy it takes to remove an electron from an atom. While they measure different things, they follow the same trend on the periodic table. Elements get more electronegative and ...
by Nell Mitchell 1E
Sun Nov 04, 2018 11:29 pm
Forum: Electronegativity
Topic: Garlic Bread Review 10d
Replies: 3
Views: 125

Re: Garlic Bread Review 10d

Ionization energy is the energy needed to remove an electron. Nitrogen has a half filled shell which is more stable than a having a half filled shell and then another electron (like oxygen). Because of this stability it takes more energy to remove an electron from nitrogen than it does to remove one...
by Nell Mitchell 1E
Sun Nov 04, 2018 11:23 pm
Forum: Lewis Structures
Topic: Expanded Octet Rule
Replies: 4
Views: 94

Re: Expanded Octet Rule

All elements row 3 and below can take on as many electrons as necessary because they have access to the d-orbital.
by Nell Mitchell 1E
Sun Nov 04, 2018 11:17 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Equation
Replies: 13
Views: 2594

Re: Formal Charge Equation

In terms of finding the the formal charge a "short cut" when looking at lewis structures is to just count each dot and line as 1 and add them all the together. The same thing as counting all unpaired electrons and adding it to 1/2 the # of bonds. Thats how one of the UAs taught it and it m...
by Nell Mitchell 1E
Sun Oct 28, 2018 11:33 pm
Forum: Trends in The Periodic Table
Topic: s-block and p-block reactivity?
Replies: 6
Views: 123

Re: s-block and p-block reactivity?

Does this mean then that ionization energy and reactivity are inverses? Like low ionization energy elements are always more reactive and less reactive elements always have high ionization energies?
by Nell Mitchell 1E
Sun Oct 28, 2018 11:31 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 4s state
Replies: 2
Views: 62

4s state

I understand the rules with 4s and 3d but I don't conceptually understand why 4s is lower energy than 3d. Can someone explain?
by Nell Mitchell 1E
Sun Oct 28, 2018 11:28 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: px,py,pz???
Replies: 6
Views: 300

Re: px,py,pz???

I've been writing out the breakdown of electrons in px py pz just as practice to make sure I understand the electron configuration conceptually (knowing to follow hund's rule) but Lavelle said that breaking it down is not necessary for purposes of correctness - px2py2pz2 is just the same as p6.
by Nell Mitchell 1E
Sun Oct 21, 2018 10:10 pm
Forum: Properties of Electrons
Topic: Concept Behind Orbitals
Replies: 6
Views: 134

Re: Concept Behind Orbitals

Hello! I was wondering if anyone could explain the concept behind nodal planes? I am having trouble conceptualizing it. Thank you! Nodal planes are areas between the orbitals where no electrons will ever be found. If you think of the p-orbital which is two petal shaped that meet in the middle the n...
by Nell Mitchell 1E
Sun Oct 21, 2018 9:57 pm
Forum: Properties of Electrons
Topic: ml
Replies: 5
Views: 167

Re: ml

I also have this problem with the different v's that all have different meanings. Is there any way you write yours so you don't mess up? For the "v" for frequency (actually greek letter nu) my TA wrote it with a line over the top in his calculations and ever since I started doing that it'...
by Nell Mitchell 1E
Sun Oct 21, 2018 5:41 pm
Forum: *Shrodinger Equation
Topic: Use of Schrodinger equation
Replies: 3
Views: 118

Re: Use of Schrodinger equation

In class he said there will not be any calculations using shrodinger, we just need to be familiar with the concept that that equation (or wave function) is where we get orbitals from. The equation indicates all the possible points where an electron could be, and the collection of all those possible ...
by Nell Mitchell 1E
Sun Oct 14, 2018 11:58 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect Initial Purpose
Replies: 4
Views: 133

Re: Photoelectric Effect Initial Purpose

My understanding was that the initial purpose of the experiment was a practical experiment to finalize the properties of different metals by identifying how much (what intensity of) light was needed to remove electrons for each metal. What they accidentally found was that the relationship they assum...
by Nell Mitchell 1E
Sun Oct 14, 2018 11:49 pm
Forum: Properties of Electrons
Topic: Diffraction patterns
Replies: 9
Views: 200

Re: Diffraction patterns

Constructive versus destructive interference are not an either/or situation - the combinations of outcomes when waves interfere exist in a gradient. When the waves peak simultaneously they are perfectly constructive, and when one peaks and the other troughs at the same time AND they are equal freque...
by Nell Mitchell 1E
Sun Oct 14, 2018 11:41 pm
Forum: Properties of Light
Topic: How light behaves
Replies: 8
Views: 207

Re: How light behaves

For understanding this I really liked Professor Lavelle's analogy of a stream of water flowing from a wide mouth faucet versus individual water molecules slipping through a very tiny faucet. In this analogy you can understand that the molecules (ie the photons) are always there and always individual...
by Nell Mitchell 1E
Sun Oct 07, 2018 11:00 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Avogadro's Constant Definition
Replies: 7
Views: 434

Re: Avogadro's Constant Definition

A mole of Cl2 refers to 6.02x10^23 molecules of Cl2. That means there would be 1.204x10^24 individual Cl atoms.
by Nell Mitchell 1E
Sun Oct 07, 2018 9:09 pm
Forum: Significant Figures
Topic: knowing how many sig figs to use
Replies: 17
Views: 694

Re: knowing how many sig figs to use

It's also important to note that leading zeros don't count as sig figs (ie 0.000234 has 3 sig figs) and that non-placeholder zeros to the right of a decimal do count as sig figs (ie 21.200 has 5 sig figs)
by Nell Mitchell 1E
Sun Oct 07, 2018 9:01 pm
Forum: Significant Figures
Topic: knowing how many sig figs to use
Replies: 17
Views: 694

Re: knowing how many sig figs to use

It's also important to note that leading zeros don't count as sig figs (ie 0.000234 has 3 sig figs) and that non-placeholder zeros to the right of a decimal do count as sig figs (ie 21.200 has 5 sig figs)
by Nell Mitchell 1E
Sun Oct 07, 2018 8:48 pm
Forum: Empirical & Molecular Formulas
Topic: Chemical Formula Element Order
Replies: 5
Views: 186

Chemical Formula Element Order

Is there a rule of thumb for the order elements should be listed in formula? For example in problem F.17, how do you know that Osmium should be listed first?

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