CHEMISTRY COMMUNITY

PriscillaLi_3G

If there is a 0 after the decimal point of a logarithmic calculation, does that count?

for example if pH=0.02, does that count as one sigfig or two?

PriscillaLi_3G

Do electrons also have wave-particle duality properties?

PriscillaLi_3G

I am confused for this question The two strands of the nucleic acid DNA are held together by hydrogen bonding between four organic bases. The structure of one of these bases, thymine, is shown below. (a) How many pro- tons can this base accept?' For part a, why can't the lone pairs on oxygen accept ...

PriscillaLi_3G

How can you tell which is the Lewis acid and Lewis base between H2O2 and H2SO5?

PriscillaLi_3G

Why does a higher electronegativity cause the charge to be distributed more evenly? I thought the more electronegative, the more an electron would be pulled to one side?

PriscillaLi_3G

I'm confused on how we're supposed to go about this problem:

Which is the stronger base, the hypobromite ion, BrO2, or morphine, C17H19O3N? Justify your answer.

Thanks!

PriscillaLi_3G

can a chelate be made up of bidentate ligands or is it only polydentate ligands?

PriscillaLi_3G

Why is hemoglobin a polydentate?

PriscillaLi_3G

What are the strong bases that we should know?

PriscillaLi_3G

How do you know if a ligand can be polydentate? I know that the metal can bond to the lone pairs but for example in Oxalate (C2O4 2-), it can be bidentate, but why is it not tetradentate? If you draw the lewis structure and do the formal charges, you will notice that there are only 2 atoms in which...

PriscillaLi_3G

What do we have to know about chelates?

PriscillaLi_3G

Which shapes do we need to know for the class?

PriscillaLi_3G

There isn't necessarily a trend. However you can apply the cation/anion trends to isoelectronic atoms.

PriscillaLi_3G

Dr. Lavelle,

Thank you for putting in so much effort in providing us resources to learn chemistry! Also, I appreciate the memes:)

Priscilla

PriscillaLi_3G

Electronegativity does not affect the size of an atom.

PriscillaLi_3G

Higher molar masses mean that there are more electrons, which means more e- e- repulsion and shielding. This makes the distortion easier, which would increase the dipole moment, thus requiring a higher boiling point to break the bonds.

PriscillaLi_3G

PranaviKolla3G wrote:Can hydrogen bonding only occur if an H atom is bonded with a N, O, or F atom?

Yes!

PriscillaLi_3G

Jessica Tran_3K wrote:I think knowing the 7 common acids would be helpful! They are:
hydrochloric acid. HCL.
hydrobromic acid. HBr.
Hydroiodic acid. HI.
Nitric acid. HNO3.
Perchloric acid. HClO4.
Sulfuric acid. H2SO4.
Chloric acid. HClO3

These are the 7 main ones you should definitely know!

PriscillaLi_3G

Ethan Breaux 2F wrote:Is water then polyprotic?

Water is not a polyprotic acid because you would start considering it from H2O and not OH-

PriscillaLi_3G

What differentiates amphoteric compounds from acids and bases?

PriscillaLi_3G

What differentiates an acid from a base?

PriscillaLi_3G

You can tell by the location of the atoms on the periodic table. Be, Al, Ga, Sn, Pb, and Sb form amphoteric compounds. Anything to the left of them on the period table forms bases, and anything to the right forms acids. Was this the diagonal line on the periodic table he was trying to explain in le...

PriscillaLi_3G

It is not cumulative.

PriscillaLi_3G

So are bond lengths always the same for all molecules due to resonance?

PriscillaLi_3G

What is the significance of antioxidants?

PriscillaLi_3G

Oxygen can have either double or triple bonds depending on the molecule.

PriscillaLi_3G

Do we have to know Sigma and Pi bonds for the test?

PriscillaLi_3G

It goes from -l to l, with all the numbers in between.

PriscillaLi_3G

It would be considered unreasonable.

PriscillaLi_3G

Nitrogen has a half-full shell, which is more stable, so it would be harder to remove an electron, thus increasing the ionization energy. In addition, the 4th electron in the oxygen atom has an electron-electron repulsion with the other electron in the orbital, thus making it easier to remove the el...

PriscillaLi_3G

Some elements (such as period 3) have empty d orbitals that can accommodate more electrons, and so we can overlook the octet rule for those atoms.

PriscillaLi_3G

E represents the energy of one photon

PriscillaLi_3G

just count the number electrons and dashes and subtract it from the atom's number of valence electrons

PriscillaLi_3G

You should give the negative formal charge to the most electronegative element because they want the electron to complete their shells and become more stable.

PriscillaLi_3G

Second best option is to get the formal charges of each atom as close to zero as possible. Give the negative formal charges to the atoms with higher electronegativity.

PriscillaLi_3G

Can E=hv be used only for electromagnetic radiation? Or can it also be applied to particles?

PriscillaLi_3G

In the Lyman series, is the final n =1 or is initial n=1?

PriscillaLi_3G

What exactly does electronegativity mean?

PriscillaLi_3G

Angstrom is a unit of length, so the numbers represent the bond length between the two atoms. I believe the reason Professor Lavelle cared to specify the lengths of the bonds is to show that single bonds are longer than double bonds.

PriscillaLi_3G

What exactly is a dipole moment?

PriscillaLi_3G

When drawing lewis structures, is the goal to have the formal charges of each atom add up as closely as possible to zero? Or for the formal charge of each individual atom to be as close to zero as possible?

PriscillaLi_3G

On the test, are we supposed to draw all the resonance structures even if it is not stated in the question?

PriscillaLi_3G

You should assume that a velocity > 3x10^8 is unreasonable

PriscillaLi_3G

A visual of the atomic radius trend in the periodic table: https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=2ahUKEwiqvKfK_7LlAhXEIjQIHTMEBPIQjRx6BAgBEAQ&url=https%3A%2F%2Fcourses.lumenlearning.com%2Fcheminter%2Fchapter%2Fperiodic-trends-atomic-radius%...

PriscillaLi_3G

As you take away an electron, you have the same positive energy power holding onto less electrons, so each electron gets a stronger pull, which makes it harder to take away a second, third, etc. electron

PriscillaLi_3G

so at each energy level, are there s- p- d- f- orbitals?

PriscillaLi_3G

It won't be tested!

PriscillaLi_3G

So is the wave function related to the quantum numbers n, l, and ml?

PriscillaLi_3G

Is it necessary that we put in the units while showing our work?

PriscillaLi_3G

E represents the energy of the photon.

PriscillaLi_3G

Different metals will require different levels of energy to break the electron away from the metal atom.

PriscillaLi_3G

Lavelle generally uses 3.0 x 10^8 in class so I believe that is fine.

PriscillaLi_3G

I was confused about how both the particle and wave models come together to model light. Is it that light is a particle and the flow of the particles (photons) are in a wave?

PriscillaLi_3G

How far away from the whole number can the number be to still be able to round? Like, if I got 1.89, could I round that to 2?

PriscillaLi_3G

Don't leave the coefficients as fractions.

PriscillaLi_3G

Why is the accuracy vs. precision concept relevant to the chemistry we are learning right now?

PriscillaLi_3G

How far off is too far off?

PriscillaLi_3G

When I am solving a problem, do I have to keep in mind the sigfigs throughout all the calculations? Or just keep the right sigfigs for the final answer.

PriscillaLi_3G

How many sig figs would you put if the original problem had no numbers in it to base your sig figs off of?

PriscillaLi_3G

How do you know when to multiply using Avogadro's number and when to divide?

PriscillaLi_3G

I take it that the term "gaseous solution" just isn't correct terminology.

PriscillaLi_3G

I think show your work in case you can get partial credit?

PriscillaLi_3G

Am I supposed to choose the 5 problems so that I do one from each topic?

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