Search found 26 matches

by Ashley Martinez 1G
Sun Jun 10, 2018 10:50 pm
Forum: Lewis Acids & Bases
Topic: Acid structure
Replies: 2
Views: 190

Acid structure

Is there a Lewis structure that implies acidity? One of the UA's mentioned an association but I am still confused about the logic behind it. She was referring to CH3COOH in her explanation. I would appreciate any clarification, thanks!
by Ashley Martinez 1G
Sun Jun 10, 2018 10:38 pm
Forum: Amphoteric Compounds
Topic: Amphoteric and amphiprotic
Replies: 6
Views: 504

Re: Amphoteric and amphiprotic

Taizha 1C wrote:Amphoteric has both acid and basic characters and properties. Amphiprotic acts as a proton donor or acceptor. An example of this would be water (H2O). It could become H3O or either -OH.


To be considered amphiprotic, does it have to act as a proton donor and acceptor, or only one of the two?
by Ashley Martinez 1G
Sun Jun 10, 2018 10:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Pi/Sigma bonds clarification
Replies: 4
Views: 115

Re: Pi/Sigma bonds clarification

I see, that definitely does help. I remember my T.A briefly mentioned that there's a shortcut in identifying which type of bonds exist by memorizing the association between single/double/triple bonds and pi/sigma bonds. Unfortunately, I don't remember exactly what the association was. Does anyone kn...
by Ashley Martinez 1G
Sun Jun 10, 2018 10:19 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7555
Views: 1010683

Re: Post All Chemistry Jokes Here

What did the proton say to the electron?

Forget you, why do you always have something negative to say?
by Ashley Martinez 1G
Sun Jun 10, 2018 10:07 pm
Forum: Lewis Acids & Bases
Topic: Determining Acid Strength
Replies: 6
Views: 346

Re: Determining Acid Strength

It might also be helpful to note acid strength can also help determine base characteristics. For example, the stronger the acid, the weaker its conjugate base. The weaker a conjugate acid, the stronger the base.
by Ashley Martinez 1G
Sun Jun 03, 2018 10:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Pi/Sigma bonds clarification
Replies: 4
Views: 115

Pi/Sigma bonds clarification

I understand pi and sigma bonds are caused by an overlap in location between electron dense regions. However I’m having trouble conceptualizing the difference between them, specifically when visualizing them. Does anyone have any tips? Thanks!
by Ashley Martinez 1G
Sun Jun 03, 2018 10:24 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar and non polar
Replies: 3
Views: 82

Re: Polar and non polar

I also had issues visualizing this. To clarify, would the dipoles cancel out if the vectors are going in opposite directions? Thanks!
by Ashley Martinez 1G
Sun Jun 03, 2018 10:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR and Lewis
Replies: 4
Views: 163

Re: VSEPR and Lewis

Taizha 1C wrote:@Ashley, because single bonds and multiple bonds are treated as equivalent in the VSEPR model, it doesn't matter which of the Lewis Structures contributing to a resonance structure we consider.

I see. Are they considered equivalent due to a rule that explicitly states this? Thanks in advance.
by Ashley Martinez 1G
Sun May 27, 2018 8:30 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecules with lone pairs
Replies: 1
Views: 86

Re: Molecules with lone pairs

Because the single unpaired electron is a region of high electron density, it's treated like a lone pair when determining molecular shape.
by Ashley Martinez 1G
Sun May 27, 2018 7:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR and Lewis
Replies: 4
Views: 163

Re: VSEPR and Lewis

When working with VSEPR models I read that it doesn't matter which resonance Lewis structure we consider, can someone explain why this is?
by Ashley Martinez 1G
Sun May 27, 2018 7:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR
Replies: 3
Views: 140

Re: VSEPR

If molecules have the same VSEPR formula they generally have the same electron arrangement and same shape. Knowing the VSEPR formula allows us to predict the shape, although there's still limitations when it comes to precise bond angle values when dealing with bond angles that aren't symmetrical.
by Ashley Martinez 1G
Sun May 20, 2018 10:41 pm
Forum: Ionic & Covalent Bonds
Topic: ionic character
Replies: 10
Views: 294

Re: ionic character

The textbook mentions that an electronegative difference of ~2 means ionic character and electronegative differences smaller than ~1.5 are regarded as covalent. It then goes on to say there's a few exceptions to these guidelines. How do we determine these exceptions? Is it something we memorize? Tha...
by Ashley Martinez 1G
Sun May 20, 2018 9:55 pm
Forum: Lewis Structures
Topic: Biradicals
Replies: 2
Views: 103

Biradicals

I read section 3.9 in the textbook but am still having trouble understanding biradicals. Why are the two unpaired electrons normally on different atoms? Why can't these unpaired electrons be on the same atom and have a non-parallel placement? Is there a method for recognizing biradicals? I'm just no...
by Ashley Martinez 1G
Sun May 20, 2018 9:38 pm
Forum: Resonance Structures
Topic: Radicals
Replies: 13
Views: 621

Re: Radicals

As far as radical placement goes, I believe we can look at electronegativity. According to the textbook, an atom of the element with the higher electronegativity has a stronger pulling power on electrons and tends to pull them away from the atom of the element with lower electronegativity. Also, I r...
by Ashley Martinez 1G
Sun May 13, 2018 9:00 pm
Forum: Ionic & Covalent Bonds
Topic: Lewis Structure vs Resonance Structure
Replies: 6
Views: 165

Re: Lewis Structure vs Resonance Structure

I think resonance structures also give a better understanding of a molecule's stability. My PLF mentioned that a molecule with many resonance structures has greater stability and is therefore less reactive than a molecule that has fewer or no resonance structures.
by Ashley Martinez 1G
Sun May 13, 2018 8:50 pm
Forum: Ionic & Covalent Bonds
Topic: Resonance [ENDORSED]
Replies: 5
Views: 230

Re: Resonance [ENDORSED]

Paywand Baghal wrote:Resonance is the blending of all the possible structures a molecule could have, correct?


Right, it's the blending of structures with the same arrangement of atoms but different arrangement of electrons.
by Ashley Martinez 1G
Sun May 13, 2018 8:43 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic vs Covalent vs Metallic Bonds
Replies: 6
Views: 234

Re: Ionic vs Covalent vs Metallic Bonds

An ionic bond is the transfer of electrons from an non-metal to a metal, a covalent bond is when two non-metals share electrons and metallic bond is when a metal exists within a mass of electrons. For ionic bonds, I understand there's a transfer of electrons, but how do we determine if the electron...
by Ashley Martinez 1G
Sun May 06, 2018 11:55 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Shells?
Replies: 7
Views: 261

Re: Shells?

Electron shells help determine energy levels. The shells closest to the nucleus have a lower energy level than those farther from the nucleus. Electrons can move from shell to shell by absorbing or releasing energy. Personally, referencing Bohr's model while reading this section in the textbook help...
by Ashley Martinez 1G
Sun May 06, 2018 11:28 pm
Forum: Trends in The Periodic Table
Topic: atomic radius
Replies: 4
Views: 135

Re: atomic radius

There's different approaches to finding the atomic radius that depend on the element's condition. If the element is a metal, its atomic radius is half the distance between the centers of neighboring atoms in a solid sample. If the element is a nonmetal or metalloid, we use half the distance between ...
by Ashley Martinez 1G
Sun May 06, 2018 11:22 pm
Forum: Trends in The Periodic Table
Topic: Electron affinity
Replies: 4
Views: 167

Re: Electron affinity

In general, electron affinities become less negative from top to bottom of a group (there's a few exceptions due to the difficulty of accurately measuring electron affinity).
by Ashley Martinez 1G
Sun Apr 29, 2018 9:42 pm
Forum: Properties of Light
Topic: light as a particle
Replies: 3
Views: 188

Re: light as a particle

"Around 1700, Newton concluded that light was a group of particles (corpuscular theory). Around the same time, there were other scholars who thought that light might instead be a wave (wave theory). Light travels in a straight line, and therefore it was only natural for Newton to think of it a...
by Ashley Martinez 1G
Sun Apr 29, 2018 9:40 pm
Forum: Properties of Light
Topic: amplitude and intensity
Replies: 11
Views: 337

Re: amplitude and intensity

Joanna Pham 1A wrote:Does the intensity just refer to the brightness of the light?

Yes, it does. Intensity/brightness of the radiation is determined by the square of the amplitude.
by Ashley Martinez 1G
Sun Apr 29, 2018 9:31 pm
Forum: General Science Questions
Topic: Tools for remembering equations
Replies: 5
Views: 514

Re: Tools for remembering equations

Although it's not necessarily an equation, my PLF gave us a fun mnemonic to memorize the types of waves from low to high frequency: "Really Man I (see) U X Genius" R= radio M= microwave I= Infra-red (see)= visible/colors U= Ultraviolet X= x-rays G= gamma-rays Memorize this and then you als...
by Ashley Martinez 1G
Sun Apr 22, 2018 11:36 pm
Forum: Properties of Light
Topic: amplitude and intensity
Replies: 11
Views: 337

Re: amplitude and intensity

I agree it's fair game for the test. If you find yourself looking for a study source about the subject, pages 146-151 in the pdf version of the textbook were pretty helpful to me
by Ashley Martinez 1G
Sun Apr 22, 2018 11:32 pm
Forum: Properties of Light
Topic: Amplitude and Intensity
Replies: 6
Views: 222

Re: Amplitude and Intensity

To my understanding, light is a form of electromagnetic radiation and intensity (i.e brightness) is determined by the square of the amplitude within the wave of electromagnetic radiation. The beginning of section 1.2 in the textbook breaks it down pretty well if you're interested!
by Ashley Martinez 1G
Sun Apr 22, 2018 10:08 pm
Forum: Properties of Light
Topic: light as a particle
Replies: 3
Views: 188

light as a particle

In regards to the results of Planck's experiment, I'm still a little confused as to how light is also a particle and how that ties in with light as a wave. I'd appreciate any clarification, thanks!

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