Search found 54 matches

by Madisen Brown -1C
Fri Dec 11, 2020 4:19 pm
Forum: Lewis Acids & Bases
Topic: general conceptual question
Replies: 9
Views: 72

Re: general conceptual question

To determine the stronger acid or base I usually refer to the list of strong acids and bases from the sapling website and base my order on that list. Here's the link for the list if needed. I've found it to be very resourceful: https://sites.google.com/site/chempendi ... cids-bases
by Madisen Brown -1C
Fri Dec 11, 2020 4:15 pm
Forum: Lewis Acids & Bases
Topic: sapling #6
Replies: 19
Views: 102

Re: sapling #6

CH3COOH has a carboxyl group therefore it's considered a weak acid because it dissociates partially to release hydrogen ions.
by Madisen Brown -1C
Fri Dec 11, 2020 4:11 pm
Forum: Lewis Acids & Bases
Topic: Water
Replies: 62
Views: 490

Re: Water

Water can act as both an acid or a base
by Madisen Brown -1C
Fri Dec 11, 2020 4:09 pm
Forum: Lewis Acids & Bases
Topic: Week 10 Sapling #6
Replies: 7
Views: 36

Re: Week 10 Sapling #6

Courtney Situ 3D wrote:Hi there!

NH3 is a weak base since it can donate electrons or accept protons from the nitrogen lone pairs. However, NaCl is not an acid or a base; it's a salt. I think you'd have to put it in the other category.

Hope that helps! :))

Yes, this helped! Thank you so much
by Madisen Brown -1C
Fri Dec 11, 2020 3:45 pm
Forum: Lewis Acids & Bases
Topic: Week 10 Sapling #6
Replies: 7
Views: 36

Week 10 Sapling #6

I seem to be having difficulty identifying the "weak bases" and "other" categories for this problem. I thought that NH3 and NaCl would be weak bases but I've attempted this solution so many times and I seem to not be understanding something. If someone could help me out that'd be...
by Madisen Brown -1C
Sun Dec 06, 2020 5:02 pm
Forum: Lewis Structures
Topic: Angles of Bonding Pairs
Replies: 8
Views: 57

Re: Angles of Bonding Pairs

I agree with what Serena mentioned, I believe it's important to know the bond angles from the VSPER model to apply it to other shapes without knowing the exact degree of the angle. More so, if it's greater than or less than, for instance, 109.5
by Madisen Brown -1C
Sun Dec 06, 2020 4:59 pm
Forum: Lewis Acids & Bases
Topic: Acids vs Basis
Replies: 11
Views: 102

Re: Acids vs Basis

I would say the identification of the acids and base (Lewis, Bronsted-Lowry, Arrhenius) and also keeping in mind important chracteristics
by Madisen Brown -1C
Sun Dec 06, 2020 4:54 pm
Forum: Resonance Structures
Topic: Stability
Replies: 13
Views: 106

Re: Stability

Resonance structures form a more stable structure due to delocalization.
by Madisen Brown -1C
Sun Dec 06, 2020 4:53 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Oxidation # Question
Replies: 4
Views: 39

Re: Oxidation # Question

The oxidation number is the total number of electrons an atom gains or loses to form a chemical bond.
by Madisen Brown -1C
Sun Dec 06, 2020 4:52 pm
Forum: Lewis Structures
Topic: Most Stable Structure
Replies: 23
Views: 117

Re: Most Stable Structure

The structures with the lowest formal charge are the most stable
by Madisen Brown -1C
Tue Nov 24, 2020 2:08 pm
Forum: Hybridization
Topic: e density
Replies: 30
Views: 133

Re: e density

Yes, regions of electron density refer to both lone pairs and bonds.
by Madisen Brown -1C
Tue Nov 24, 2020 2:02 pm
Forum: Hybridization
Topic: hybridization of phosphorus (Sapling Q.11)
Replies: 21
Views: 96

Re: hybridization of phosphorus (Sapling Q.11)

Though one of the oxygens is double-bonded to phosphorus, this only constitutes as one region of electron density
by Madisen Brown -1C
Tue Nov 24, 2020 1:56 pm
Forum: Hybridization
Topic: Delocalization [ENDORSED]
Replies: 4
Views: 59

Re: Delocalization [ENDORSED]

Delocalization means the electrons are shared equally through the molecule. For bonds, electrons are typically shared just between the two atoms in the bond. When electrons are delocalized, then they are shared equally throughout and is not shared with just two atoms. Since these electrons are delo...
by Madisen Brown -1C
Mon Nov 23, 2020 1:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sapling #8
Replies: 5
Views: 53

Re: Sapling #8

The bonds of both molecules are polar because their electronegativities are different. For BeCl2, the shape of the molecule is linear because there are no lone pairs on the central atom that would cause the molecule to bend or be angular. In a linear shape, the dipoles cancel each other out therefor...
by Madisen Brown -1C
Mon Nov 23, 2020 1:23 pm
Forum: Hybridization
Topic: Delocalization [ENDORSED]
Replies: 4
Views: 59

Delocalization [ENDORSED]

During Lavelle's lecture today when he was discussing the hybridization of benzene I noticed him refer to some of the electrons, as well as the sigma and pie bonds of benzene, as being delocalized so I was wondering what he meant by "delocalized" in this context.
by Madisen Brown -1C
Wed Nov 18, 2020 6:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 11/18/20 Lecture VSEPR Notation
Replies: 4
Views: 24

Re: 11/18/20 Lecture VSEPR Notation

Yes. X represents the bond atom and E represents the lone pair around the central atom.
by Madisen Brown -1C
Wed Nov 18, 2020 6:57 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bonding
Replies: 5
Views: 47

Re: Bonding

I usually take formal charge into consideration when determining whether a single, double, or triple bond would yield the most stable structure.
by Madisen Brown -1C
Wed Nov 18, 2020 6:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pair E-
Replies: 47
Views: 263

Re: Lone Pair E-

Lone pair electrons are included in the region of electron density.
by Madisen Brown -1C
Wed Nov 18, 2020 6:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shape Names
Replies: 50
Views: 299

Re: Shape Names

Yep! The shape is known as bent or angular because 2 of the 4 bonding sites are lone pairs and the lone pairs force the bonding electrons closer which decreases the bond angle.
by Madisen Brown -1C
Wed Nov 18, 2020 12:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Topic 2E Exercises: Question 2E.3
Replies: 1
Views: 18

Topic 2E Exercises: Question 2E.3

How do you determine whether there can be lone pairs on the central atom when given the shape? For instance, in this question, they give a trigonal planar structure and a linear structure.
by Madisen Brown -1C
Thu Nov 12, 2020 8:44 pm
Forum: Lewis Structures
Topic: Trouble with question 1 on sapling.
Replies: 3
Views: 18

Re: Trouble with question 1 on sapling.

The structure should have a doubled bond between C and O (C being the central atom), two lone pairs on O, and two single H bonds. It could be coming up as wrong if you're missing the double bond. Hope this helps!
by Madisen Brown -1C
Thu Nov 12, 2020 8:38 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Sapling week 5/6 #5
Replies: 6
Views: 57

Re: Sapling week 5/6 #5

Carbon has a charge of -2!
by Madisen Brown -1C
Thu Nov 12, 2020 8:34 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge vs Octet Rule
Replies: 12
Views: 226

Re: Formal Charge vs Octet Rule

I agree with the other responses! The octet rule should be the primary concern before a formal charge.
by Madisen Brown -1C
Thu Nov 12, 2020 8:30 pm
Forum: Octet Exceptions
Topic: Elements that can have Expanded Octet
Replies: 5
Views: 28

Re: Elements that can have Expanded Octet

Elements in row 3 or higher can have expanded octets because they can make use of the d-orbitals. Hope this helps!
by Madisen Brown -1C
Thu Nov 12, 2020 8:25 pm
Forum: Electronegativity
Topic: Sapling #14
Replies: 10
Views: 73

Re: Sapling #14

Hydrogen bonds only with the three most electronegative atoms: N, O, and F. Therefore, O must be on either side to form an H-bond. Hope this helps!
by Madisen Brown -1C
Sun Nov 08, 2020 7:05 pm
Forum: Ionic & Covalent Bonds
Topic: Size of Bonds
Replies: 28
Views: 99

Re: Size of Bonds

Because double bonds have a higher number of electrons, the electrons are pulled in tighter thus the bond length is shorter
by Madisen Brown -1C
Sun Nov 08, 2020 7:02 pm
Forum: Resonance Structures
Topic: Electron spin
Replies: 12
Views: 47

Re: Electron spin

From my understanding, there's no definitive way to calculate the spin up or spin down. I think it's mainly important to know that no element has the same 4 quantum numbers.
by Madisen Brown -1C
Sun Nov 08, 2020 6:58 pm
Forum: Electronegativity
Topic: Lewis Acids and Bases (Sapling #6)
Replies: 4
Views: 42

Re: Lewis Acids and Bases (Sapling #6)

Lewis acids are ones that accept an electron. Lewis bases on the other hand donate electrons. Hope this helps!
by Madisen Brown -1C
Sun Nov 08, 2020 6:55 pm
Forum: Lewis Structures
Topic: lewis structure
Replies: 17
Views: 49

Re: lewis structure

The positive and negative symbols represent the charge of the molecule. Hope this helps!
by Madisen Brown -1C
Sun Nov 08, 2020 6:51 pm
Forum: Student Social/Study Group
Topic: Midterm 2 Study Group
Replies: 25
Views: 152

Re: Midterm 2 Study Group

Thanks for organizing this!
by Madisen Brown -1C
Sun Nov 01, 2020 1:41 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8512
Views: 1470802

Re: Post All Chemistry Jokes Here

I ain't never seen two identical fermion particles in the same quantum state. It's always one of them gotta have different quantum numbers.
by Madisen Brown -1C
Tue Oct 27, 2020 2:09 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra Post-Module Assessment #44
Replies: 4
Views: 45

Re: Atomic Spectra Post-Module Assessment #44

Andrew Jubintoro 3B wrote:
here n1 is the lower energy level and n2 is the higher energy level.
n1 = 1
n2 = 4
I think you might have switched the two.

I think that is what happened thanks for the help!
by Madisen Brown -1C
Tue Oct 27, 2020 2:09 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra Post-Module Assessment #44
Replies: 4
Views: 45

Re: Atomic Spectra Post-Module Assessment #44

Uyenvy Nguyen 3C wrote:Did you get a negative value for your frequency? For the frequency, I got positive 3.08*10^15, and I plugged it into the equation wavelength=c/frequency and got 9.73*10^-8 meters. This would be in the UV region.

I believe so, but that makes sense. I think I might've miscalculated somewhere.
by Madisen Brown -1C
Tue Oct 27, 2020 2:07 pm
Forum: Properties of Electrons
Topic: Atomic Spectra Post-Module Assessment #28
Replies: 3
Views: 36

Re: Atomic Spectra Post-Module Assessment #28

Andrew Jubintoro 3B wrote:1 meter = 1,650,763.73 wavelengths
Therefore, 1/1,650,763.73 meter = 1 wavelength
1 wavelength = 6.058 x 10-7 m = 605.8 nm
So it's in the visible light region.
E = hc/ = 3.28 x 10-19 J

Thanks for the help!
by Madisen Brown -1C
Mon Oct 26, 2020 10:03 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra Post-Module Assessment #44
Replies: 4
Views: 45

Atomic Spectra Post-Module Assessment #44

The question reads: In the hydrogen atomic spectrum, what is the wavelength of light associated with the n = 4 to n = 1 electron transition? What part of the electromagnetic spectrum is this wavelength? When I used Rydberg's equation, I got the answer to be -9.73E-8 but the answer is incorrect. Coul...
by Madisen Brown -1C
Mon Oct 26, 2020 9:56 pm
Forum: Properties of Electrons
Topic: Atomic Spectra Post-Module Assessment #28
Replies: 3
Views: 36

Atomic Spectra Post-Module Assessment #28

The question reads: The meter was defined in 1963 as 1,650,763.73 wavelengths of radiation emitted by krypton-86 (it has since been redefined). What is the wavelength of this krypton-86 radiation? To what region of the electromagnetic spectrum does this wavelength correspond (i.e. infrared, ultravio...
by Madisen Brown -1C
Fri Oct 23, 2020 2:06 pm
Forum: DeBroglie Equation
Topic: De Broglie Equation v. Speed of Light Equation
Replies: 14
Views: 101

Re: De Broglie Equation v. Speed of Light Equation

Hi! The speed of light equations are used when you want to find the wavelength/frequency of a photon, so you can't use it for other objects. You can instead use DeBroglie's equation to find the wavelength! Also, sometimes the question asks if an object's wavelength is detectable/not detectable, whi...
by Madisen Brown -1C
Fri Oct 23, 2020 2:05 pm
Forum: DeBroglie Equation
Topic: De Broglie Equation v. Speed of Light Equation
Replies: 14
Views: 101

Re: De Broglie Equation v. Speed of Light Equation

When you are finding the wavelength of something that has mass is when you should be using de Broglie, like an electron or an object. Therefore, you cannot use this to calculate the wavelength of photons because they have no mass and must use the other equation to find the wavelength of light. That...
by Madisen Brown -1C
Fri Oct 23, 2020 11:58 am
Forum: DeBroglie Equation
Topic: De Broglie Equation v. Speed of Light Equation
Replies: 14
Views: 101

De Broglie Equation v. Speed of Light Equation

I'm having difficulty comprehending when to use De Broglie's equation to find the wavelength and when to use the speed of light equation to find the wavelength. Are there certain conditions for the different equations that I should be aware of? Or any given information/keywords used in a problem tha...
by Madisen Brown -1C
Fri Oct 23, 2020 11:54 am
Forum: Balancing Chemical Reactions
Topic: Chemical Compounds
Replies: 4
Views: 49

Re: Chemical Compounds

Quinton Sprague 2D wrote:I was wondering the same thing. If you check out the post titled "Midterm Nomenclature" it appears to be answered by a TA who says that we will not be expected to know/balance formulas like nitric acid, phosphoric acid, or other compounds as such.

That's a relief! Thank you
by Madisen Brown -1C
Thu Oct 22, 2020 8:06 pm
Forum: Balancing Chemical Reactions
Topic: Chemical Compounds
Replies: 4
Views: 49

Chemical Compounds

Is anyone aware if, for MT1, we need to know more complex chemical compounds like sulfite, nitrate, chromate, etc., aside from the basic chemical compounds like water or oxide in the case that we need to write the chemical equation and balance it?
by Madisen Brown -1C
Fri Oct 16, 2020 1:30 pm
Forum: Properties of Light
Topic: Textbook Problem 1A. 3
Replies: 7
Views: 88

Re: Textbook Problem 1A. 3

could someone explain why d is wrong? i understand why c is correct but i thought the radiation of a wave was related to frequency because radiation/intensity was equal to the square of wavelength which is related to frequency? if this isnt true, what is the radiation of a wave proportional to? D i...
by Madisen Brown -1C
Wed Oct 14, 2020 6:44 pm
Forum: Properties of Light
Topic: Textbook Problem 1A. 3
Replies: 7
Views: 88

Re: Textbook Problem 1A. 3

In question 3 of focus topic IA, I understand why options A,B, and D are wrong. However, I do not understand why C is correct. I am confused about how the extent of change in the electrical field relates to EM radiation. What is the "extent of change" referring to in the question? The wor...
by Madisen Brown -1C
Wed Oct 14, 2020 12:31 pm
Forum: Properties of Electrons
Topic: Lyman vs. Balmer series
Replies: 20
Views: 164

Re: Lyman vs. Balmer series

Are we going to have to memorize the difference between the Lyman and Balmer series? I think it's important to remember that Balmer represents the visible light region (n=2) and that Lyman represents the ultraviolet region (n=1). Without this information, it'd be difficult to solve for n1 and n2 wh...
by Madisen Brown -1C
Wed Oct 14, 2020 12:22 pm
Forum: Einstein Equation
Topic: m vs nm
Replies: 66
Views: 447

Re: m vs nm

I don't think it's necessary if it doesn't specify converting the final answer in nm. However, the wavelength is usually referred to in nm so it might be of benefit to get in the habit of doing the conversion.
by Madisen Brown -1C
Wed Oct 14, 2020 12:15 pm
Forum: Properties of Light
Topic: Textbook Problem 1A. 3
Replies: 7
Views: 88

Re: Textbook Problem 1A. 3

In question 3 of focus topic IA, I understand why options A,B, and D are wrong. However, I do not understand why C is correct. I am confused about how the extent of change in the electrical field relates to EM radiation. What is the "extent of change" referring to in the question? The wor...
by Madisen Brown -1C
Tue Oct 13, 2020 3:05 pm
Forum: Properties of Light
Topic: Relationship Between Wavelength and Energy
Replies: 4
Views: 22

Re: Relationship Between Wavelength and Energy

Hello! You can use the energy per photon equation (E=hv) and c=(lambda)v to determine the relationship. If you were to rearrange the speed of light equation, you would get v=c/(lambda). You can substitute this into the energy per photon equation so E=hc/(lambda). This may help you visualize the rel...
by Madisen Brown -1C
Tue Oct 13, 2020 2:18 pm
Forum: Properties of Light
Topic: Relationship Between Wavelength and Energy
Replies: 4
Views: 22

Relationship Between Wavelength and Energy

So, I understand that wavelength and frequency are inversely related, and because a higher frequency usually indicates the particle has more energy, is it accurate to say the relationship between wavelength and energy are also inversely related?
by Madisen Brown -1C
Tue Oct 13, 2020 2:13 pm
Forum: Properties of Light
Topic: Electromagnetic Spectrum
Replies: 7
Views: 55

Re: Electromagnetic Spectrum

As you move down the Electromagnetic Spectrum, from red (700nm) to violet (400 nm), the wavelength decreases. Inversely, as the wavelength of a particle decreases, the frequency of that particle increases. So, in context, the color red has a lower frequency than violet. Hope this establishes a bette...
by Madisen Brown -1C
Tue Oct 06, 2020 8:09 pm
Forum: Limiting Reactant Calculations
Topic: Sapling #10 Step by Step
Replies: 6
Views: 64

Re: Sapling #10 Step by Step

I have gotten a 1:1 ratio and converted the product to grams to find the theoretical yield, but I am unsure of what to do after this After converting the limiting reactant to the product in grams, you'll then want to solve for the percent yield by dividing the actual yield (given in the problem) by...
by Madisen Brown -1C
Tue Oct 06, 2020 8:05 pm
Forum: Balancing Chemical Reactions
Topic: Stoichiometric Coefficients
Replies: 20
Views: 147

Re: Stoichiometric Coefficients

Alara Aygen 2E wrote:Hi,
Sometimes some of the coefficients may be missing. So even though you see one stoichiometric coefficient, the rest of the equation may be unbalanced. It is always good to check before solving the question.

Thanks for clarifying! I'll be sure to double-check before proceeding with the problem
by Madisen Brown -1C
Tue Oct 06, 2020 8:01 pm
Forum: Balancing Chemical Reactions
Topic: HW H.21
Replies: 5
Views: 52

Re: HW H.21

Oxygen gas is O2 in this case. When elements are in their natural state some of them appear in doubles. You know its a double in this case because you're told its oxygen gas.These elements that naturally appear as doubles are labelled as diatomic molecules. I think they're hydrogen, nitrogen, oxyge...
by Madisen Brown -1C
Mon Oct 05, 2020 5:48 pm
Forum: Balancing Chemical Reactions
Topic: HW H.21
Replies: 5
Views: 52

HW H.21

The problem reads, "The psychoactive drug methamphetamine (“speed”), which is sold as the prescription medication Desoxyn, C10H15N, undergoes a series of reactions in the body; the net result of these reactions is the oxidation of solid methamphetamine by oxygen gas to produce carbon dioxide ga...
by Madisen Brown -1C
Mon Oct 05, 2020 11:42 am
Forum: Balancing Chemical Reactions
Topic: Stoichiometric Coefficients
Replies: 20
Views: 147

Stoichiometric Coefficients

Can we assume that a problem with the stoichiometric coefficients already given in the chemical equation is balanced? In other words, would there ever be a scenario where the stoichiometric coefficients are given, but the equation isn't balanced?

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