CHEMISTRY COMMUNITY

Melody Zhang 3L

For question 12.9 pt.C, 6th edition, how come there is no proton transfer from CH3COOH --> CH3CONH2?

Melody Zhang 3L

It is because F is the one with the negative charge and is able to bind with the H+ atom

Melody Zhang 3L

Do we need to know specifically what oxalato, en, dien, and edta stand for and their molecular formulas, or just their denticity?

Melody Zhang 3L

Iodine has 7 valence electrons, so at first, I allocated 3 lone pairs around each of the Iodines, with the central iodine having a formal charge of -1. However, I realized that I was taught to place the negative charge on the outside atoms whenever possible, so I made one of the lone pairs of the ce...

Melody Zhang 3L

I just wanted to clarify in a lewis structure whether we should draw the arrows pointing to the positive or negative dipole? In my notes from the lecture, I drew the arrows pointing to the negative dipole, but I think the textbook prefers drawing the arrow pointing to the positive dipole.

Melody Zhang 3L

sorry I meant based on electronegativity, CF4 should be the weakest

Melody Zhang 3L

For #87, Chapter 3, 6th edition, why does CF4 have the strongest bond? Based on electronegativity, the strength of CF4 should be the strongest right?

Melody Zhang 3L

For 6th edition CH3 #43, is there an easier way to identify all the resonance structures of the molecule?

Melody Zhang 3L

Actually, I just searched it up and it says that 02 is more polarizable than n3 because 02 is larger than n3

Melody Zhang 3L

Polarizability does depend on both the charge and the atomic radius, and it increases as atomic radius increases and charge decreases. In this case, I believe N3- is more polarizable because there was a greater difference between atomic radii.

Melody Zhang 3L

It isn't necessary but 2sp3 is more specific because it is the second shell.

Melody Zhang 3L

Do we need to draw out the dashed line and bold line when asked to draw the lewis structure?

Melody Zhang 3L

I assume there examples we will be given will have molecules with atoms of obviously different electronegativity, for example NH3 or H2O and we're not expected to know the exact electronegativity.

Melody Zhang 3L

Dipole moments are the measurements of the separation of two opposite electric charges, for example the charge of H and the charge of O in the molecule H2O. Nonpolar molecules have very small or no dipole moments while polar molecules have a higher dipole moment.

Melody Zhang 3L

You can think of 5 atoms surrounding a central atom as composed of two pyramids, so it's trigonal bipyramid, three atoms surrounding one central atom as a flat molecule, so it is trigonal planar. When you see tetrahedral, just think of 4 surrounding atoms because tetra=4

Melody Zhang 3L

For the sixth edition chapter 3 #37, when given a lewis structure and asked to identify the element in the center, can we just explain our answer by saying that only an element with 5 valence electrons would make the formal charge 0, and the only element in period 3 with 5 valence electrons is Phosp...

Melody Zhang 3L

Would we need to know how to identify compounds such as ammonium chloride and draw the lewis structure without knowing the formula? I also had trouble figuring out which bonds were covalent and which were ionic without seeing the charges on the formula. (NH4+ CL-)

Melody Zhang 3L

How would one draw this lewis structure? I thought we were not supposed to place the negative formal charge on the central atom.

Melody Zhang 3L

The same idea does apply to the 5s orbital, and it is filled before 4d. However, there is no 4f electron configuration for period five, as 4f1 begins after lanthanum. I don't think we need to know the specific patterns of period 5, like why it is 4d4 5s1 instead of 4d3 5s2, just be able to count the...

Melody Zhang 3L

Thanks so much!

Melody Zhang 3L

Does anyone know if we need to memorize the patterns for electron configuration for period 5 and below? They differ from the exceptions in period 4, like chromium is 3d5 4s1 instead of 3d4 4s2, because in period 5, niobium is 4d45s1 instead of 4d3 5s2.

Melody Zhang 3L

For the hw problem, 3.5 part b, the ground state electron configuration for Bi3+ was 4f14, 5d10, 6s2. I thought it would be just 6s2 because the electron configuration of Bi is 6s2, 6p3. Can someone clarify where the 4f14 and 5d10 came from?

Melody Zhang 3L

The two are essentially the same but I think we need to use En=-hR/n^2 for the class.

Melody Zhang 3L

The wave function is a function that varies depending on the position of the particle. Using the Schrodingers equation we can find the wave function and the energy. I don't think we need to know the equation for the class.

Melody Zhang 3L

I understand why we use the noble gases to write the shorthand version of the electron configuration for say the element Chromium, but I'm not sure how we're supposed to know exactly what number to start on after. For example, Chromium is [Ar] 3d5 4s1, but how do we know to start on 3d?

Melody Zhang 3L

I'm confused. Have we ever covered the Boltzmann law or Wien's law in class? If not will we need to review on our own?

Melody Zhang 3L

Delta v is the amount of uncertainty in the electron's velocity. Because the uncertainty was greater than the speed of light and was an unrealistic number, it proves that electrons do not collapse to the nucleus.

Melody Zhang 3L

Can anyone clarify which equations we need to know? I'm kind of lost with the Rydberg expression v=R(1/n21-1/n22), Weins Law, and the Bohr Frequency condition: hv=E(upper)-E (lower).

Melody Zhang 3L

The amplitude is the height of the wave and it corresponds with he intensity of the light. I don't believe amplitude is related to frequency because the intensity of light is different from the energy of each photon, which is related to the wavelength and frequency.

Melody Zhang 3L

The reason the textbook used the 6.62608 x 10-34 Js was to match the number of sigfigs given (140.511 keV). If the given number has less sigfigs, I believe you can use 6.63 x 10-34 Js.

Melody Zhang 3L

Does anyone know how to convert from keV to joules?

Melody Zhang 3L

Yes, you add the molar mass of 5H2O to the molar mass of CuSO4 to find the amount in grams of CuSO4*5H2O needed and multiply that with the amount in moles of CuSO4 (0.20mol/L)(.250L).

Melody Zhang 3L

I see, thanks!

Melody Zhang 3L

For problem F9 (sixth edition), how is the ratio 1 oxygen 2.67 hydrogen and 2.67 carbon converted to the empirical formula C8H8O3? I understand that the ratio is multiplied by three but I don't see how to tell what multiple to multiply the ratio with.

Melody Zhang 3L

I believe they are asking you to find the empirical formula after you find the mole ratio of the compound.

CHEMISTRY COMMUNITY

Search found 35 matches

Proton transfer

Re: Writing Ion Formulas

Do we need to know en, edta?

Lewis Structure for I3-

Drawing dipole moments

Re: Strength of covalent bonds

Strength of covalent bonds

Resonance Structures

Re: Difference between O2- and N3-

Re: Difference between O2- and N3-

Re: Using hybrid orbitals

Drawing out Molecular Shape

Re: Is it best to memorize electronegativity?

Re: Dipole Moments

Re: Molecular shapes

Identifying the element

Identifying compounds

BH4-

Re: Filling of Orbitals

Re: Electron Config for period 5

Electron Config for period 5

How to write electron config for Bi3+?

Re: Q. 1.57

Re: Solutions to the Schrodinger Equation

Electron Configurations

Stefan-Boltzmann law and Wien's law

Re: Incorrect Atomic Model

Formulas?

Re: Light

Re: Problem 1.23

Problem number 1.23 [ENDORSED]

Re: Q G17 part b. (7th edition)

Re: Converting from mole ratios to empirical formula

Converting from mole ratios to empirical formula

Re: HW 1 Problem F.9