Search found 46 matches

by Montana James 4G
Thu Dec 05, 2019 9:21 am
Forum: Amphoteric Compounds
Topic: Amphoteric Oxides
Replies: 2
Views: 21

Re: Amphoteric Oxides

I think they tend to be formed with elements near the metalloids on the periodic table. for example, Al and sometimes As.
by Montana James 4G
Thu Dec 05, 2019 9:17 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: London disperson
Replies: 6
Views: 23

London disperson

just to clarify, all molecules can have london dispersion forces, right? can someone explain why?
by Montana James 4G
Thu Dec 05, 2019 9:13 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: when to use Heisenberg
Replies: 2
Views: 33

Re: when to use Heisenberg

I feel like when you're supposed to use the equation, the question will directly ask you to solve for the uncertainty in position or velocity
by Montana James 4G
Wed Dec 04, 2019 4:06 pm
Forum: Lewis Acids & Bases
Topic: 6A17 - SO3 and As2O3
Replies: 1
Views: 23

6A17 - SO3 and As2O3

I don't understand how SO3 is acidic? How could it accept an electron?

Also, how can As2O3 act as both an acid and a base?
by Montana James 4G
Tue Dec 03, 2019 11:54 pm
Forum: Identifying Acidic & Basic Salts
Topic: Cations groups 1 and 2
Replies: 2
Views: 22

Re: Cations groups 1 and 2

I think it has to do with the low oxidation numbers of group 1 and 2 cations as well as the stability of their anions. It's too difficult for cations with low oxidation states to remove H+.
by Montana James 4G
Tue Dec 03, 2019 11:46 pm
Forum: Identifying Acidic & Basic Salts
Topic: Classifying Salts
Replies: 5
Views: 36

Re: Classifying Salts

follow up question: wouldn't BaCl be one of the salts that doesn't affect pH because Ba+ is in group 2?
by Montana James 4G
Tue Dec 03, 2019 7:16 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: acidic trends
Replies: 3
Views: 29

acidic trends

Am I correct in saying the strength of an acid is related to electronegativity of the central atom? Can someone elaborate on this?
by Montana James 4G
Tue Dec 03, 2019 7:14 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6C17 - strength of bases
Replies: 4
Views: 50

6C17 - strength of bases

Why is BrO- a stronger base than C17H19O3N?
by Montana James 4G
Wed Nov 27, 2019 9:51 pm
Forum: Bronsted Acids & Bases
Topic: Lewis and Bronsted
Replies: 4
Views: 25

Lewis and Bronsted

kind of a stupid question, but I'm just confirming that a Lewis base is the same thing as a Bronsted base, just with different ways of explaining it? in other words, am I correct in saying that it's not possible for a substance to be both a lewis acid and a bronsted base?
by Montana James 4G
Wed Nov 27, 2019 9:45 pm
Forum: Bronsted Acids & Bases
Topic: Writing Chemical Equations
Replies: 2
Views: 24

Re: Writing Chemical Equations

if you're talking about neutralization reactions, what I do is make H2O (a lot of the time the hydroxide comes from the base and the other H comes from the acid) and then pair whatever is leftover to make a salt.
by Montana James 4G
Fri Nov 22, 2019 6:06 pm
Forum: Naming
Topic: Prefixes
Replies: 4
Views: 36

Re: Prefixes

I think he was saying that you use those to name the whole coordination compound if the polydentate ligand attached to a central metal atom already has a greek prefix (di-, tri-, etc) in its name.
by Montana James 4G
Fri Nov 22, 2019 6:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity and melting and boiling points
Replies: 3
Views: 19

Re: Polarity and melting and boiling points

To add on: the stronger the intermolecular force, the higher the melting/boiling point (generally speaking)
by Montana James 4G
Tue Nov 19, 2019 11:21 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Figuring Out Bond Angle
Replies: 3
Views: 18

Re: Figuring Out Bond Angle

Also you can't find out quantitatively how much smaller the distorted angle is, you can only determine that it is slightly smaller.
by Montana James 4G
Tue Nov 19, 2019 11:19 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Sigma and Pi Bonds and Resonance
Replies: 3
Views: 18

Re: Sigma and Pi Bonds and Resonance

I don't think so. Each resonant structure should have the same number of sigma and pi bonds, right?
by Montana James 4G
Mon Nov 18, 2019 11:25 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape vs Electron Geometry
Replies: 4
Views: 29

Re: Molecular Shape vs Electron Geometry

I always think of it as that electron geometry only considers how many regions of electron density there are (i.e. 3 regions = trig planar) while molecular geometry considers whether there are lone pairs or bonded pairs (i.e. 2 bonded pairs, 1 lone pair= bent). also this chart is helpful! https://co...
by Montana James 4G
Mon Nov 18, 2019 11:21 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Hydrogen bonding
Replies: 2
Views: 22

Hydrogen bonding

Still struggling to understand hydrogen bonding...I think I might be overthinking it but can someone explain in what situation would it occur? And why, for example, does a water molecule have 4 possible places for hydrogen bonds?
by Montana James 4G
Mon Nov 18, 2019 11:18 pm
Forum: Hybridization
Topic: hybridization
Replies: 11
Views: 57

Re: hybridization

from what I understand, you look at how many regions of electron density there are and using that number to choose a hybridization scheme. In the end, the number of regions of electron density should equal the number of hybridized orbitals.
by Montana James 4G
Mon Nov 18, 2019 11:15 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: polarity
Replies: 5
Views: 34

polarity

why are some molecules that are symmetrical (like CH2Cl2) polar? shouldn't the symmetry mean that the dipoles can cancel?
by Montana James 4G
Mon Nov 18, 2019 11:13 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: How to know which angles are smaller
Replies: 8
Views: 44

Re: How to know which angles are smaller

The lone pair pushes the other regions of electron density closer to each other, making the bond angles smaller. but we can only do this qualitatively, we don't know exactly how much they change.
by Montana James 4G
Wed Nov 13, 2019 10:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E #5
Replies: 4
Views: 43

Re: 2E #5

in general, include leach lone pair as a region of electron density along with the covalent bonds. in this case, like the previous replies said, the shape is bent.
by Montana James 4G
Wed Nov 13, 2019 10:40 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: What’s the Difference
Replies: 6
Views: 74

Re: What’s the Difference

anions are polarizable and the bigger they are, the more polarizable they are. cations have polarizing power that depends on how strongly they can pull the anion's electrons.
by Montana James 4G
Wed Nov 13, 2019 10:37 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: dipole moment clarification
Replies: 6
Views: 30

Re: dipole moment clarification

follow up question, is the permanent dipole part of the definition of a polar molecule? in other words, what defines polar?
by Montana James 4G
Wed Nov 13, 2019 10:29 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: dipole moment clarification
Replies: 6
Views: 30

dipole moment clarification

to clarify, are dipole moments are describing intermolecular forces? and how are intermolecular forces related to polarity?
by Montana James 4G
Wed Nov 13, 2019 10:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles Exceptions
Replies: 6
Views: 38

Bond Angles Exceptions

Dr. Lavelle mentioned that sometimes a bond angle in a tetrahedral will be more or less than 109.5 degrees. when would this be the case?
by Montana James 4G
Tue Nov 05, 2019 10:07 pm
Forum: Electronegativity
Topic: Ionization Energy
Replies: 3
Views: 27

Re: Ionization Energy

I don't know if this is the best way to explain it but here's how I think of it: Oxygen has four electrons in the p orbital (one pair and two unpaired). It is relatively easy to remove one of the paired electrons, making its ionization energy lower than nitrogen which is relatively stable with one e...
by Montana James 4G
Tue Nov 05, 2019 10:01 pm
Forum: Resonance Structures
Topic: Formal Charge Question
Replies: 15
Views: 97

Re: Formal Charge Question

They just have to sum up to the same overall charge, as far as I know. Not sure if this is what you mean, but some resonant structures are more stable than others due to the formal charges of all the atoms being lower (i.e, all of them being 0 or +1 versus one atom being +2 and others being 0)
by Montana James 4G
Wed Oct 23, 2019 10:36 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: subshell or orbital?
Replies: 3
Views: 44

subshell or orbital?

Is it correct to call it the s,p,d,f orbital or the s,p,d,f subshell? I feel like I've heard it said both ways but which is right...?
by Montana James 4G
Wed Oct 23, 2019 10:28 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: order
Replies: 3
Views: 24

Re: order

I think it's because the d-orbital has lower energy than the s-orbital for some elements
by Montana James 4G
Wed Oct 23, 2019 10:25 pm
Forum: Ionic & Covalent Bonds
Topic: Octet Rule
Replies: 6
Views: 55

Re: Octet Rule

because they have too few electrons to form an octet
by Montana James 4G
Wed Oct 23, 2019 10:21 pm
Forum: Ionic & Covalent Bonds
Topic: Double Bond vs Single Bond Length
Replies: 6
Views: 116

Re: Double Bond vs Single Bond Length

to add on, I think Dr Lavelle said that in actual experimental data, all the bond lengths are the same (1.24A). So the Lewis structure is just a model.
by Montana James 4G
Wed Oct 23, 2019 1:42 pm
Forum: Trends in The Periodic Table
Topic: types of radii
Replies: 4
Views: 45

types of radii

I understand the tendency for radii to increase down a group and decrease across a period, but what's the difference between atomic, ionic, and covalent radii? thanks in advance :)
by Montana James 4G
Thu Oct 17, 2019 1:08 am
Forum: Properties of Electrons
Topic: Momentum
Replies: 11
Views: 48

Re: Momentum

mass*velocty=momentum(kg*m/s) like the other replies said, it's different from velocity but they're definitely related. if there's no velocity, there also can't be any momentum.
by Montana James 4G
Thu Oct 17, 2019 12:57 am
Forum: Quantum Numbers and The H-Atom
Topic: Ground State [ENDORSED]
Replies: 5
Views: 78

Ground State [ENDORSED]

what does it mean for an atom to be in ground state?
by Montana James 4G
Thu Oct 17, 2019 12:54 am
Forum: Quantum Numbers and The H-Atom
Topic: spin up and spin down
Replies: 7
Views: 40

Re: spin up and spin down

someone correct me if I'm wrong but I think Lavelle said that the numbers are arbitrary, they're just used to represent one state or the other.
by Montana James 4G
Thu Oct 17, 2019 12:53 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: how to express answer
Replies: 6
Views: 24

Re: how to express answer

pretty sure it depends on what your calculating. like previous response said, you're usually solving for delta(position/velocity/momentum/etc) in which case you use the equal sign.
by Montana James 4G
Tue Oct 15, 2019 10:36 pm
Forum: DeBroglie Equation
Topic: Wavelength of Radiation
Replies: 3
Views: 33

Wavelength of Radiation

How would you find the wavelength of the radiation that caused photoejection of the electron (as in question 1B15 part c)? I have the values for energy required to eject the electron, frequency of the radiation, and velocity of the electron emitted. Do you use the c=wavelength*frequency equation or ...
by Montana James 4G
Thu Oct 10, 2019 1:00 am
Forum: Photoelectric Effect
Topic: Kinetic Energy from the Photoelectric Effect
Replies: 5
Views: 54

Re: Kinetic Energy from the Photoelectric Effect

It makes the electron move at a certain velocity
by Montana James 4G
Thu Oct 10, 2019 12:53 am
Forum: SI Units, Unit Conversions
Topic: Angstrom
Replies: 16
Views: 201

Angstrom

What is an angstrom and do we need to know it for test?
by Montana James 4G
Thu Oct 10, 2019 12:40 am
Forum: Limiting Reactant Calculations
Topic: Net Ionic Equation
Replies: 6
Views: 90

Re: Net Ionic Equation

For questions asking about net ionic equation, you do also have to write the full balanced equation in order to calculate percent yield and other information about the products, right?
by Montana James 4G
Thu Oct 10, 2019 12:37 am
Forum: Properties of Electrons
Topic: Rydberg formula clarification
Replies: 3
Views: 36

Re: Rydberg formula clarification

I think he meant that Rydberg's is just like a shortcut. It's derived from Bohr's equation but it doesn't help you understand the concepts, so he said to use the other equation, E=-hR/n^2.
by Montana James 4G
Wed Oct 09, 2019 12:36 am
Forum: Molarity, Solutions, Dilutions
Topic: Question L37, Volume of H2O
Replies: 2
Views: 40

Question L37, Volume of H2O

Answer to question L37 says, (a) Pipette 31 mL of 16 m HNO3 into a 1.00 L volumetric flask that contains about 800 mL of H2O. Dilute to the mark with H2O. I calculated the 31ml of 16M HNO3, but where does the 800ml come from? How do you find this value? *edit, I know this is not an assigned hw probl...
by Montana James 4G
Thu Oct 03, 2019 9:36 pm
Forum: SI Units, Unit Conversions
Topic: How to format homework
Replies: 9
Views: 111

Re: How to format homework

Yes, my TA also said to put your discussion section and it doesn't hurt to put your ID on there too
by Montana James 4G
Thu Oct 03, 2019 9:33 pm
Forum: SI Units, Unit Conversions
Topic: E.7 Chemical Principle 7th edition
Replies: 4
Views: 63

Re: E.7 Chemical Principle 7th edition

The above responses are perfect, but for conversion questions in general it may also be helpful to think of Avogadro's number as 6.022 x 10^23 "things" (be it atoms, molecules, etc.) in one mole. From there it makes it easier to see what you need to divide or multiply.
by Montana James 4G
Thu Oct 03, 2019 9:28 pm
Forum: Limiting Reactant Calculations
Topic: Study Strategies/Youtube Videos
Replies: 14
Views: 158

Re: Study Strategies/Youtube Videos

I've always liked crash course to help overview conceptual stuff. For specific questions, posting them on here is definitely not a bad idea
by Montana James 4G
Thu Oct 03, 2019 9:23 pm
Forum: Limiting Reactant Calculations
Topic: Calculating Theoretical Yield
Replies: 9
Views: 88

Calculating Theoretical Yield

I know that theoretical yield is directly related to the limiting reactant, but how do you know how much of the limiting reactant is used in the reaction? Would it just be the whole amount given in the problem?-- In which case, the theoretical yield would be the same number as the number of grams of...
by Montana James 4G
Thu Oct 03, 2019 9:10 pm
Forum: Significant Figures
Topic: Sig figs in intermediate steps??
Replies: 5
Views: 34

Re: Sig figs in intermediate steps??

I was always told not to round until the end when you have a final answer. you can underline the correct amount of sigfigs throughout the problem to help keep track.

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