Search found 30 matches

by Harmonie Ahuna-1C
Thu Jun 07, 2018 12:44 am
Forum: Lewis Acids & Bases
Topic: Weak vs strong acids [ENDORSED]
Replies: 7
Views: 298

Re: Weak vs strong acids [ENDORSED]

In the textbook it talks about how organic acids are weaker than acetic acids so depending on the compound, you can try to deduce strength based off of chemical formula. The formula for organic acids is COOH, and acetic acids are CH3COOH.
by Harmonie Ahuna-1C
Thu Jun 07, 2018 12:37 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelating complex
Replies: 7
Views: 118

Re: Chelating complex

The textbook cites a chelate as a complex with more than 1 ligand forming a ring of atoms with the central metal atom. These must occur with polydentate ligands.
by Harmonie Ahuna-1C
Thu Jun 07, 2018 12:29 am
Forum: Bronsted Acids & Bases
Topic: How to identify a Bronsted acid or base
Replies: 11
Views: 377

Re: How to identify a Bronsted acid or base

How can you tell if it is a Bronsted acid or base without the reaction though? For example, on J1, you are asked to identify if it is a Bronsted acid or base just by the compound. How would you do this? I'm also confused on how to do this. How can we tell whether or not a hydrogen has been donated ...
by Harmonie Ahuna-1C
Wed May 30, 2018 4:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Drawing
Replies: 7
Views: 166

Re: VSEPR Drawing

We'll need to know the bond angles, and not necessarily how to draw the geometric shape, but we will need to be able to identify them.
by Harmonie Ahuna-1C
Wed May 30, 2018 4:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: HW 4.13 part c
Replies: 4
Views: 77

Re: HW 4.13 part c

I don't see any errors in your reasoning and I do think the 2 double bonded oxygens would produce a more favorable molecule. I guess the only good thing is that the whether they're double or single bonds wouldn't affect the shape or bond angles for the problem.
by Harmonie Ahuna-1C
Wed May 30, 2018 4:35 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.3 Homework
Replies: 3
Views: 89

Re: 4.3 Homework

HCN is linear because lone pairs only affect shape when they're on the central atom- so only if they were on carbon would we see a different shape. For CH2N2, C is the central atom paired with all 4 atoms, making it tetrahedral.
by Harmonie Ahuna-1C
Sat May 26, 2018 9:55 am
Forum: Resonance Structures
Topic: ranking
Replies: 11
Views: 368

Re: ranking

vivianndo_1L wrote:If the two resonance structures have the same formal charge, would they be considered equal in rank?


I believe so
by Harmonie Ahuna-1C
Sat May 26, 2018 9:53 am
Forum: Electronegativity
Topic: Electronegativity Caluclations
Replies: 4
Views: 188

Re: Electronegativity Caluclations

I'm not sure if we'll ever be given them, so it's helpful to just know the trend- that electronegativity increases as you go across a period and decreases as you go down.
by Harmonie Ahuna-1C
Sat May 26, 2018 9:44 am
Forum: Formal Charge and Oxidation Numbers
Topic: Formal charge with ions
Replies: 4
Views: 170

Re: Formal charge with ions

You calculate it the same as you would if there were no charge, and should get the overall charge of the ion when adding up the formal charges of each atom.
by Harmonie Ahuna-1C
Thu May 24, 2018 3:42 pm
Forum: Dipole Moments
Topic: Meaning of an induced dipole
Replies: 3
Views: 147

Re: Meaning of an induced dipole

The energy values he gave refer to the energy of the attraction.
by Harmonie Ahuna-1C
Thu May 24, 2018 3:26 pm
Forum: Octet Exceptions
Topic: Confusion on exceptions to the octet rule
Replies: 2
Views: 152

Re: Confusion on exceptions to the octet rule

I believe it starts at the beginning of the p group of period 3 with aluminum because silicon can have an expanded octet. In aluminum's case though, while I think it could potentially have an expanded octet, like Boron it can function well with 6 electrons so often has a reduced one.
by Harmonie Ahuna-1C
Thu May 24, 2018 3:16 pm
Forum: Dipole Moments
Topic: Non-polar and dipoles
Replies: 3
Views: 91

Re: Non-polar and dipoles

A molecule can have dipole moments and be nonpolar if the polar bonds are symmetrical and the same charge, meaning they could potentially cancel each other out.
by Harmonie Ahuna-1C
Sat May 19, 2018 3:00 pm
Forum: Octet Exceptions
Topic: Expanded Octet Rules
Replies: 7
Views: 367

Re: Expanded Octet Rules

It begins with the non-metals in the third period or below, they are able to do this because they have empty d subshells that can house the extra electrons. Based off of what we learned with quantum numbers and electron shells & subshells, I always thought 3p came before 3d so how is this possi...
by Harmonie Ahuna-1C
Sat May 19, 2018 2:58 pm
Forum: Octet Exceptions
Topic: Exceptions [ENDORSED]
Replies: 7
Views: 333

Re: Exceptions [ENDORSED]

ALSO! remember to look at formal charges! I think this is one of the easiest ways to determine if extra electrons or bonds are needed. If you know the atom includes the d orbital and you follow the octet rule and have electrons left over which lead to a charge, then you can try to determine if you ...
by Harmonie Ahuna-1C
Sat May 19, 2018 2:50 pm
Forum: Lewis Structures
Topic: Test #3
Replies: 11
Views: 262

Re: Test #3

Specifically what hw questions we should know how to do for this test? Based off of what's included on his outline for chapter 3 and since we did electron configurations on the midterm, I would say it'd be useful to do 3.33 and upwards which includes covalent bond problems which have to do with bui...
by Harmonie Ahuna-1C
Sun May 06, 2018 7:34 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration Exceptions
Replies: 2
Views: 107

Re: Electron Configuration Exceptions

Yes, for the midterm I think we only have to know copper and chromium. However, this does show up in some hw problems so the exception where the s shell only has 1 electron is also true for the elements in the column just below Cr and Cu, which are molybdenum and silver. This is for the same reason,...
by Harmonie Ahuna-1C
Sun May 06, 2018 7:23 pm
Forum: Trends in The Periodic Table
Topic: Trends to Know
Replies: 12
Views: 394

Re: Trends to Know

Another trend is electron affinity. Electron affinity tells how how much energy must either be supplied (-) or is released(+) when an electron attaches to an atom. It generally increases as you move right and up along the periodic table. However, noble gases in group 18 have low ones because they're...
by Harmonie Ahuna-1C
Sun May 06, 2018 7:18 pm
Forum: Trends in The Periodic Table
Topic: 2.67 part C (electron affinity)
Replies: 3
Views: 65

Re: 2.67 part C (electron affinity)

I was also confused about this problem but electron affinity is discussed in section 2.11 on pages 56-57. Though the general trend is that electron affinities are highest toward the right of the periodic table, figure 2.28 indicates that nitrogen is relatively more stable than carbon. It shows the e...
by Harmonie Ahuna-1C
Sun Apr 29, 2018 9:23 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: ∆P and ∆X
Replies: 5
Views: 167

Re: ∆P and ∆X

Specifically, deltaP is the uncertainty in momentum and deltaX is uncertainty in position of something. These allow us to estimate how big or small our uncertainty about either one of these is. For example, 3 x 10^(5) has a larger uncertainty than 3 x 10^(-29). We can also use Heisenberg's to find t...
by Harmonie Ahuna-1C
Sun Apr 29, 2018 9:15 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Finding velocity (delta)V [ENDORSED]
Replies: 2
Views: 62

Re: Finding velocity (delta)V [ENDORSED]

Also, another way to do these problems as seen in the book's example is to set it up as deltaV= (h/2pi)/(2*m*deltaX) so you combine the two steps
by Harmonie Ahuna-1C
Sun Apr 29, 2018 9:10 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: In class problem [ENDORSED]
Replies: 6
Views: 280

Re: In class problem [ENDORSED]

In this case, because we solved for the uncertainty in velocity we could compare the value to the speed of light because nothing can travel faster than it. I'm not sure what we would compare if we were looking at other things like the reasonability of uncertainty in position.
by Harmonie Ahuna-1C
Sun Apr 22, 2018 5:14 pm
Forum: Photoelectric Effect
Topic: Significance of intensity [ENDORSED]
Replies: 7
Views: 154

Re: Significance of intensity [ENDORSED]

Continuing off that note, when light acts as a wave, or for any wave, the intensity relates to the amplitude/height of the wave. Specifically, I think in one part of the textbook it referenced that in terms of the wave model intensity is proportional to the square of amplitude to the wave. It also ...
by Harmonie Ahuna-1C
Sun Apr 22, 2018 5:11 pm
Forum: Photoelectric Effect
Topic: Photoelectric Post-Module [ENDORSED]
Replies: 3
Views: 116

Re: Photoelectric Post-Module [ENDORSED]

I was also confused about part b for this problem. If we do divide the work function by Avogadro's number as previously suggested, we'd only get one of the answer options if we don't convert 150.6 kJ to 150,600 J, which is something I feel like we'd have to do??
by Harmonie Ahuna-1C
Sun Apr 22, 2018 4:41 pm
Forum: Properties of Light
Topic: test 2
Replies: 18
Views: 494

Re: test 2

QuincyH1G wrote:Is test 2 only on the Quantum World? Will there be anything before that covered?


Yep! It'll just be the quantum world, specifically up to 1.5 in the textbook which covers the wave-particle duality of matter and De Broglie's wave equation.
by Harmonie Ahuna-1C
Sun Apr 15, 2018 2:57 pm
Forum: Molarity, Solutions, Dilutions
Topic: When to use MiVi=MfVf
Replies: 8
Views: 312

Re: When to use MiVi=MfVf

Are there some cases where you'll have to use both the M=n/v and MiVi=MfVf equations in a problem?
by Harmonie Ahuna-1C
Sun Apr 15, 2018 2:48 pm
Forum: Photoelectric Effect
Topic: Intensity VS Energy Models? [ENDORSED]
Replies: 4
Views: 117

Re: Intensity VS Energy Models? [ENDORSED]

To add on to this, does light intensity matter for the photoelectric effect?
by Harmonie Ahuna-1C
Sun Apr 15, 2018 2:00 pm
Forum: Properties of Light
Topic: Properties of Light [ENDORSED]
Replies: 5
Views: 146

Re: Properties of Light [ENDORSED]

A photon is a particle representing a quantum of light or other electromagnetic radiation. I believe the concept is that light shares characteristics of acting as a wave and as a particle. Photons experience refraction like a wave but it also contains a fixed energy like a particle. I hope this hel...
by Harmonie Ahuna-1C
Sun Apr 15, 2018 1:55 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical and Molecular Formulas [ENDORSED]
Replies: 4
Views: 131

Re: Empirical and Molecular Formulas [ENDORSED]

Yeah this is correct. For the molecular formula because it's the "actual" number of atoms all we had to do was count them and for the empirical formula, because it's the "relative" number of atoms per element, we could use the molecular formula we to find the ratio for the amount...
by Harmonie Ahuna-1C
Sun Apr 15, 2018 1:50 pm
Forum: SI Units, Unit Conversions
Topic: Chemistry Review Section E
Replies: 4
Views: 142

Re: Chemistry Review Section E

Yes, in that question when it asks for the amount of ions it essentially means the same thing as finding the mols of Cu2+ ions in the overall CuBr2 compound. For this, you'd divide the given amount of CuBr2 (3 g) by the total molar mass of the compound (in g/mol). Then, because there's 1 mol of Cu2+...
by Harmonie Ahuna-1C
Sun Apr 15, 2018 1:37 pm
Forum: SI Units, Unit Conversions
Topic: Moles mols mol? [ENDORSED]
Replies: 18
Views: 569

Re: Moles mols mol? [ENDORSED]

Naqiyah Qadir 1I wrote:They are all the same but M (molarity) is given in moles/Liter, correct?


Yep! And the hint for when to use that is it often asks for what the "concentration" of the solution is.

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