Search found 20 matches

by Eryn Wilkinson 3H
Fri Dec 08, 2017 2:15 pm
Forum: Bronsted Acids & Bases
Topic: Determining acidity
Replies: 3
Views: 337

Re: Determining acidity

I think this has a lot to do with the fact that the more resonance a molecule has, the more stable it is. For example, we talked about how benzene is very stable because it has delocalized electrons, and the carbon-carbon bonds are all in between single and double bond lengths. The molecule is stabl...
by Eryn Wilkinson 3H
Fri Dec 08, 2017 10:31 am
Forum: Conjugate Acids & Bases
Topic: 12.9 d
Replies: 1
Views: 241

12.9 d

I see how the equation NH4I (am) + KNH2 (am) > KI (am) + 2NH3 (l) is a Bronsted reaction, and NH4+ is the acid and NH2- is the base, but I am confused on what their conjugates would be. Do all Bronsted reactions have conjugate acid/base pairs?
by Eryn Wilkinson 3H
Wed Nov 29, 2017 7:58 pm
Forum: Conjugate Acids & Bases
Topic: Chemical Formula
Replies: 5
Views: 444

Chemical Formula

How do you identify whether it is an acid or a base just by looking at the chemical formula?
by Eryn Wilkinson 3H
Wed Nov 29, 2017 5:51 pm
Forum: Naming
Topic: [CO(SO4)(NH3)5]+ [ENDORSED]
Replies: 2
Views: 2766

Re: [CO(SO4)(NH3)5]+ [ENDORSED]

SO4 has a charge of -2 automatically and NH3 has no charge. Since there is an overall charge of +1, Co must be +3, because it cancels out the -2 charge of SO4 and has a net charge of +1 left over.
by Eryn Wilkinson 3H
Sun Nov 26, 2017 8:14 pm
Forum: Octet Exceptions
Topic: Midterm Question 8B
Replies: 2
Views: 343

Re: Midterm Question 8B

I drew it H-O-C=O with two lone pairs on each O and a single electron on the C. This has formal charges of 0 for all of the elements and gives each O a full octet, which makes sense because it is the more electronegative element so it should be pulling more electrons toward it. That's how I thought ...
by Eryn Wilkinson 3H
Sun Nov 26, 2017 7:45 pm
Forum: Naming
Topic: 17.31 part c
Replies: 2
Views: 254

Re: 17.31 part c

How do you know that it is Br3 and not 3BR- ? Does it make a significant difference when answering the question?
by Eryn Wilkinson 3H
Sun Nov 19, 2017 9:52 pm
Forum: Hybridization
Topic: Hybridization
Replies: 2
Views: 212

Re: Hybridization

I find that it helps to figure out how many regions of electron density there are! I don't think it is necessary, though, because you could figure this out just based on the number of atoms attached and lone pairs without drawing it out.
by Eryn Wilkinson 3H
Sun Nov 19, 2017 9:08 pm
Forum: Hybridization
Topic: bent molecular structure [ENDORSED]
Replies: 4
Views: 443

Re: bent molecular structure [ENDORSED]

If there are 4 regions of electron density then the electron arrangement will be tetrahedral. If only 2 of those regions are bonding pairs then the molecular shape will be bent, because no matter which pairs you make attached to the central atom the bond angle will be slightly less than 109.5 degrees.
by Eryn Wilkinson 3H
Mon Nov 13, 2017 4:06 pm
Forum: Ionic & Covalent Bonds
Topic: Midterm
Replies: 6
Views: 646

Re: Midterm

How do you know that SiO2 is polar if you don't know the specific electronegativity difference? The elements seem fairly close together on the periodic table, and since there are two oxygens wouldn't the dipole moments cancel?
by Eryn Wilkinson 3H
Mon Nov 13, 2017 3:59 pm
Forum: Hybridization
Topic: Homework Help: Problem 4.73
Replies: 2
Views: 235

Re: Homework Help: Problem 4.73

The shape would actually be approached as trigonal pyramidal, because the VSEPR formula is AX3E. This means that there is one lone pair on top, and 3 bonding pairs of electrons being repelled by it. The bond angles would be slightly less than 109.5 degrees, which is the usual bond angle for tetrahed...
by Eryn Wilkinson 3H
Sun Nov 05, 2017 2:42 pm
Forum: Lewis Structures
Topic: Homework 3.99
Replies: 1
Views: 238

Re: Homework 3.99

I think this is really just trial and error! It helps to draw it the way Professor did in lecture where you draw it with all single bonds first and then change some of the lone pairs to double bonds to make sure that it is the correct number of electrons. Also just remember that N can't have an expa...
by Eryn Wilkinson 3H
Sun Nov 05, 2017 2:38 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 3
Views: 425

Re: Resonance Structures

I think that it really helps to draw out the Lewis structures when determining resonance, because it's just all of the different places that a double or triple bond could be in. Sometimes there is only one spot that it is possible for a double bond to exist in, but other times, like in benzene, the ...
by Eryn Wilkinson 3H
Sat Oct 28, 2017 12:46 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Difference Between Orbitals and Subshells [ENDORSED]
Replies: 7
Views: 1265

Re: Difference Between Orbitals and Subshells [ENDORSED]

N is the shell, or the overall energy level (thinking of a Bohr diagram it is a new ring each time). L is the subshell, which further organizes the energy level into s, p, d, and f. Ml is the orbital, so if you drew out each level it would be each "box" with two electrons in it (_+_-_). Ms...
by Eryn Wilkinson 3H
Sat Oct 28, 2017 12:39 pm
Forum: Quantum Numbers and The H-Atom
Topic: 2.19
Replies: 1
Views: 248

Re: 2.19

If n=6 then l can be 0-5. However, this question gives you more information and says that it n=6 and l=2, and asks you for the ml values specifically for that energy level.
by Eryn Wilkinson 3H
Sun Oct 22, 2017 10:26 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Quantum Number l exception [ENDORSED]
Replies: 4
Views: 437

Re: Quantum Number l exception [ENDORSED]

The value of l is a maximum of (n-1), so it can be all numbers up to that value. If the subshell is an s orbital, l is always 0, because the s orbital can only hold 2 electrons and therefore does not have any smaller subdivisions. So if you look at the energy levels, n=1 can only have an s orbital (...
by Eryn Wilkinson 3H
Sun Oct 22, 2017 10:17 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration for silver [ENDORSED]
Replies: 1
Views: 506

Electron Configuration for silver [ENDORSED]

In lecture we went over how the 4s orbital gets filled before the 3d orbital because it has a lower energy. Is this the same for all levels? I thought that it was, but the electron configuration given for silver in the solutions manual (ch. 2 #43) is [Kr]4d^105s^1. Can someone please explain this to...
by Eryn Wilkinson 3H
Sun Oct 15, 2017 1:23 pm
Forum: DeBroglie Equation
Topic: 1.55
Replies: 2
Views: 221

Re: 1.55

I think that this is actually referring to energy. It says in the background of the problem that vibrational energy is expressed in reciprocal centimeters (cm^-1), and you can convert this to frequency by multiplying it by the speed of light.
by Eryn Wilkinson 3H
Tue Oct 10, 2017 2:30 pm
Forum: Properties of Electrons
Topic: Energy Levels [ENDORSED]
Replies: 1
Views: 283

Energy Levels [ENDORSED]

Hi y'all, so on ch. 1 question 15 it asks you to find the initial and final energy levels of the hydrogen, but it expects you to know that hydrogen starts at n1=1. Is that because hydrogen has one electron so it automatically starts in the first energy level? How would you find out what energy level...
by Eryn Wilkinson 3H
Sat Oct 07, 2017 5:01 pm
Forum: Balancing Chemical Reactions
Topic: Question about Moles of a Compound in a Balanced Chemical Equation [ENDORSED]
Replies: 3
Views: 772

Re: Question about Moles of a Compound in a Balanced Chemical Equation [ENDORSED]

The mass on both sides of the equation has to be equal, but not the number of moles (like on the test when it asked for the net number of moles produced). The coefficients balance the equation because the number of atoms of each element on each side has to be the same, so if there are 2 moles of Na ...
by Eryn Wilkinson 3H
Thu Oct 05, 2017 3:24 pm
Forum: Limiting Reactant Calculations
Topic: Problem M11 part a
Replies: 5
Views: 535

Re: Problem M11 part a

Is there a way to combine the two reactions and solve from there just using molar ratios? I attempted that way but got it wrong so just wondering if anyone accomplished it?

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