CHEMISTRY COMMUNITY

Megan Potter 1G

What is a porphyrin ligand? (ex. would come from 19-23 of Lyndon's french toast test)

Megan Potter 1G

I know AX5E means 6 total regions of electron density, so an octahedral electron arrangement. However, one of the bonds is a lone pair, leaving 5 bonds from the central atom to other atoms. This would make a square pyramidal, which makes sense, but I was under the impression that a lone pair deflect...

Megan Potter 1G

He also said he preferred the s to do first and my TA writes it that way as well so you prob won't get points taken off either way

Megan Potter 1G

When we label sigma and pi bonds, like for CH4, I know looking at one of those C-H would be σ(C2sp^3, H1S). I was just wondering what the 2 for C and 1 for H referred to? is it just the row number?

Megan Potter 1G

What are conjugate acids and bases?

Megan Potter 1G

Megan Potter 1G wrote:12.49) Which is the stronger base, the hypobromite ion, BrO-, or morphine, C17H19O3N? Justify

Can someone explain what makes one base stronger than another?

just to add, the solutions manual says "the smaller the pKb (b is a subscript) of a base, the stronger the base". what is pKb?

Megan Potter 1G

12.49) Which is the stronger base, the hypobromite ion, BrO-, or morphine, C17H19O3N? Justify

Can someone explain what makes one base stronger than another?

Megan Potter 1G

So any atom in row 3 or greater can have an expanded octet. If you think back to when we did s, p, d, f stuff, having an n = 2 (row 2) would give us an l = 0, 1, which are the s and p orbitals. However, when we go to n = 3, l = 0, 1, 2 which are the s, p, and d orbitals. Now we can have an expanded ...

Megan Potter 1G

Also drawing this molecule in a line would result in formal charges not equal to zero so the only way to draw it while minimizing the formal charges on the atoms would to draw it as a square

Megan Potter 1G

Ionic character is relative to another atom, so not all small atoms may have ionic character. Like O2 is a fairly small atom (according to the trends), but because it's bonded with another O (that has the same electronegativity) then it's covalent because they are sharing equally. Same with if you h...

Megan Potter 1G

those are the same thing, it doesn't really matter whether you put the line connecting to the oxygen below or to the side because its still between the C and H

Megan Potter 1G

is there some rule that states the formal charge on the central atom should be zero? like if you have to have atoms within a molecule with a +1 and -1 to make the overall charge 0, is there a rule that states the central atom should have a formal charge of 0 and the other atoms should be the ones wi...

Megan Potter 1G

So in a UA session, we learned when you are writing the Lewis structure for a molecule that has a charge, the most electronegative atom should carry the negative charge. for example, in OCN-, Oxygen is the most electronegative. When drawing the structure, one of the atoms needs to have a -1 to make ...

Megan Potter 1G

2.1 is just an example, but the question is "Which member of each pair has the smaller first ionization energy?"
a) Ca or Mg?
b) Mg or Na?
c) Al or Na?

Can someone explain to me what ionization energy is and what it means to have a smaller FIRST ionization energy?

Megan Potter 1G

How far in the periodic table do we need to know for electron configuration stuff? To krypton (so 3d, 4s, 4p)?

Megan Potter 1G

so if ml is -1, then that means 2 electrons because the ml is specified? whereas with 2p, for example, the n=2 and l=1, which gives ml=-1, 0, +1 and each of those could have 2 electrons, right? which then ties in with why the p-orbital fills with 6 electrons? If someone could confirm this or explain...

Megan Potter 1G

How many electrons can have the following quantum numbers in an atom: b) n=4, l=2, ml=-2 d) n=3, l=2, ml=+1 So for these I understand (using b for example) n=4 and l=2 would be the 4d orbital, and the values of ml could be -2, -1, 0, +1, and +2 (so 5 orbitals). I'm confused though on what exactly ml...

Megan Potter 1G

I also used wavelength=hc/E, but the way you do it works too. With rounding the answer is 10 x 10^7 (positive exponent of 7, not negative, because there's 10^9 nanometers in one meter) If you don't mind explaining more, just so I can possibly understand, why would 10^9 nanometers in one meter make ...

Megan Potter 1G

So if you solve the equation you get this: Wavelength = {(6.626 x 10^-34)(2.998 x 10^8)}/(1.99 x 10^-24) wavelength = .099821 meters there are 10^9 nanometers in one meter (nanometers are smaller so it makes sense that there should be a ton of them to make one meter) using dimensional analysis to co...

Megan Potter 1G

what is electron affinity? like for the question: Which has a higher electron affinity - Chlorine (Cl) or Neon (Ne)?

Megan Potter 1G

"What are the principal and orbital angular momentum quantum numbers for each of the following orbitals:
a) 6p
b) 3d
c) 2p
d) 5f
"

I said n= 6, 3, 2, and 5 in that order for the principal quantum numbers. How would you find the angular momentums? is that l?

Megan Potter 1G

D states: how many subshells are there in the shell with n=4?

I was under the assumption that n described the size and energy of the orbital. Can someone explain how this correlates with subshells so how you would know the number of subshells with n=4? I'm lost

Megan Potter 1G

In a simple way, any electron in an atom can be described by four quantum numbers (s, m, l, n) which help you find the electron. n is the energy level of the shell, l tells you the type of orbital, m tells you which of the l orbitals you are in, and s sort of tells you the direction of the spin of t...

Megan Potter 1G

And to find the number of photons, use the equation E=hc/wavelength. then take the total Energy (64J) and divide that by the Energy you just found (which is J/photon --> 473x10^-19) to get the number of photons which is 1.35x10^20 photons.

Megan Potter 1G

I also used wavelength=hc/E, but the way you do it works too. With rounding the answer is 10 x 10^7 (positive exponent of 7, not negative, because there's 10^9 nanometers in one meter)

Megan Potter 1G

Not sure which topic to put this under:

39) A baseball must weigh between 5.00 and 5.25 ounces (1 ounce 28.3 g). What is the wavelength of a 5.15-ounce baseball thrown at 92 mph?

How would you go about solving something like this? Not sure which equation I should be using.

Megan Potter 1G

The formula for kinetic energy is E = mv 2 /2. m is the mass of the moving object (electron is being emitted; so electron mass) and v is the velocity of that moving object. mass of electron is the one you have stated. I'm still confused on this too. so is 9.109x10^-31 always going to be the mass of...

Megan Potter 1G

oops I just mistyped in my question. I got 4.86 x 10^-7 not 17. thanks!

Megan Potter 1G

Use the Rydberg formula for atomic hydrogen to calculate the wavelength of radiation generated by the transition from n=4 to n=2. (b) What is the name given to the spectroscopic series to which this transition belongs? (c) Use Table 1.1 to determine the region of the spectrum in which the transition...

Megan Potter 1G

h is just Planck's constant which is 6.626x10^-34 and v is your frequency

Megan Potter 1G

Atomic spectroscopy is the study of electromagnetic radiation absorbed and emitted by atoms. Different atoms have different spectrums (or spectra might be the plural idk) so when you analyze them you can determine the elemental compositions.

Megan Potter 1G

So an example of this came up in G 11: A medical researcher investigating the properties of intravenous solutions prepared a solution containing 0.278 m C6H12O6 (glucose). What volume of solution should the researcher use to provide 4.50 mmol C6H12O6? For this problem I understand that 0.278 is my M...

Megan Potter 1G

The solutions manual has a solution for part (a) when it asks you to find the limiting reactant so definitely do the calculations.

Megan Potter 1G

Definitely check with a TA but from talking to other students who took 14A with Lavelle in the past they said we don't need to know those compounds yet and we will have a whole unit on all that stuff.

Megan Potter 1G

My TA said that sig figs wouldn't cause a loss in points this quarter. She said in the past students had to watch them and then people ended up focusing more on sig figs and rounding correctly than doing the problem right in the amount of time given. She recommends if you are using a calculator keep...

CHEMISTRY COMMUNITY

Search found 35 matches

Porphyrin Ligand

Shape of AX5E

Re: Hybrid Orbitals

Composition of a bond (Sigma and Pi Bonds)

Conjugate Acids and Bases

Re: 12.49 Determining Base Strength

12.49 Determining Base Strength

Re: Exoanding

Re: 3.47

Re: Ionic character

Re: 3.41 c [ENDORSED]

formal charge on central atom

Which atom to have the charge in lewis structures

Ionization Energy (2.61) [ENDORSED]

Re: Midterm Topics [ENDORSED]

Re: 2.29 b & d

2.29 b & d

Re: Test #2: Q6 [ENDORSED]

Re: Test #2: Q6 [ENDORSED]

Electron Affinity

2.21

2.19 part d

Re: quantum numbers [ENDORSED]

Re: Homework question 1.27 [ENDORSED]

Re: Test #2: Q6 [ENDORSED]

HW 1.39 [ENDORSED]

Re: Example 1.5 [ENDORSED]

Re: 1.13 (b)

1.13 (b)

Re: Calculating the energy of a photon [ENDORSED]

Re: Confusion about Atomic Spectroscopy [ENDORSED]

G.11 / Volumes for Solutions

Re: M11 HW

Re: Common Compounds to know

Re: Which mass of Hydrogen should I use?