CHEMISTRY COMMUNITY

Tina Wen 1G

Thank you that explains everything perfectly.

Tina Wen 1G

I'm not sure if someone has already posted about this, but could someone help me with the final question in Test 3 (a)? I don't get why the double bond in the structure on the left has a shorter bond length compared to the one on the right? How exactly do you know if a specific bond is shorter in on...

Tina Wen 1G

Generally for T-shape if you disregard the influence of the lone pairs stating that the angles are 90 degrees and 180 degrees is fine. But with real life experiments there might be slight differences according different T-shaped structures.

Tina Wen 1G

I think we need to distinguish weak acids from strong acids. Just remember the 7 strong acids and the rest are weak acids.

Tina Wen 1G

Both C and O have sp2 hybridization. Bond angle is 120 degrees. And sp2 means one sigma bond and two pie bonds.

Tina Wen 1G

In this case, the two Chlorine atoms and be connected to two adjacent carbon atoms/ skipping one carbon atom/ opposite carbon atoms. Only when connected to opposite carbon atoms of the benzene ring the dipole moment is canceled out. Imagine two people with the same force pulling a string — the force...

Tina Wen 1G

Yes thinking about resonance structure would help! For SO4 each S-O bond is something between single and double bond, whereas SO3 is solid double bond, which makes it stronger

Tina Wen 1G

I thought this was the name of a movie haha. But anyways the shape should be bent. The shape is first more determined by the number of bonding pair which is 2 in this case. And then consider the presence of lone pairs which results in repulsion and distortion of the linear structure. A trigonal pyra...

Tina Wen 1G

I see the point. But N has one fewer full shell than Cl which contributes to its electronegativity. I think it’s more understandable to say that N has fewer valence electrons and thus more bonding opportunities than Cl without breaking the octet rule. Also NO2 is like pretty common combination.

Tina Wen 1G

Does shorter bond length always leads to stronger bond? Any exceptions?

Tina Wen 1G

Usually the atom with the fewest valence electrons is the central atom. It has more space accept electrons shared with other atoms. Hence carbon goes in the middle since it has 4 valence electrons and can form 4 bonds with surrounding atoms.

Tina Wen 1G

HCHO shows the structure of the molecule while H2CO, or the more commonly used CH2O is the standard molecular formula that does not indicate structure.

Tina Wen 1G

Compared to single bond, triple bond means more electrons are shared, shorter bond length, and stronger connection between the bonding atoms. Therefore, single bond is weaker than triple bond.

Tina Wen 1G

If that is required by the question. If it’s not mentioned then it’s safer to draw all resonance structure.

Tina Wen 1G

We can break the octect rule when the bonding atom has empty d or f orbitals that are available for additional bonding. We should always find the optimized bonding with individual formal charge closest to zero. First try following the octect rule but if involving d or f orbitals would lead to more s...

Tina Wen 1G

2 double bonds with 2 oxygen atoms and sulfur in the middle with a lone pair is the most stable structure for SO2. Sulfur has the empty 3d orbital that can participate in bonding so it’s okay for sulfur to carry more than 8 electrons.

Tina Wen 1G

Having more protons mean that the atom/ion has stronger ability to attract electrons towards the center nucleus. Hence the smaller the atomic radii. Hope this helps.

Tina Wen 1G

: answer

Tina Wen 1G

: answer

Tina Wen 1G

How should we solve the difference in energy for Q4 in Test 2? And what is the final answer? Thank you

Tina Wen 1G

Hi, how detailed should the electron configurations be? Can we always apply shorthand parentheses like [Ar] 3s^2? For p sublevels do we need to notify the x, y and z orbitals when writing the configurations (eg. 2px^2 2py^1 2pz^1)?

Tina Wen 1G

For the final question in test 2, how many electrons can 1 thousand photons of UV region send to higher energy levels? What is the quantitative relationship of energy transfer from photons to electrons?

Tina Wen 1G

During Friday class the professor mentioned E=hv only applies to light and lambda=h/p applies to everything else with mass but light? I wonder why is that?

Tina Wen 1G

So we won't be tested on the original equation that explains the concept?

Tina Wen 1G

Hi I think the solution manual is not being precise here. During emission the H-atom should move from higher energy levels to lower ones. So technically it should be a transition from n2=3 to n1=1. Also n1 < n2 because that makes their squared reciprocals 1/n1^2 > 1/n2^2. Correct me if I'm wrong.

Tina Wen 1G

1.11 In the spectrum of atomic hydrogen, several lines are generally classi ed together as belonging to a series (for example, Balmer series, Lyman series, Paschen series), as shown in Figs. 1.10 and 2.1. What is common to the lines within a series that makes grouping them together logical? What wou...

Tina Wen 1G

Do we need to know the basic mechanisms and process of the historical experiments on the nature of atoms? Like how the scientists determined the nuclear model of the atom including protons, electrons, neutrons, etc?

Tina Wen 1G

Hey I'm wondering what are the key figures and formulas to memorise for this chapter? Like do we need to know the range of frequency and wavelength for different radiation type (eg. x-ray, microwave, visible light)? Or the range of Balmer and Lyman series?

Tina Wen 1G

For F.25 (b), do we write (CH2)2(NH2)2 or H2N(CH2)2NH2 for molecular formula?

Tina Wen 1G

https://www.unc.edu/~rowlett/units/sipm.html
In all there are seven SI base units:
the meter for distance,
the kilogram for mass,
the second for time,
the ampere for electric current,
the kelvin for temperature,
the mole for amount of substance, and.
the candela for intensity of light.

Tina Wen 1G

We know that the notation for mass is m, molar quantity is n. What is the notation for molar mass?

CHEMISTRY COMMUNITY

Search found 31 matches

Re: Test 3 Final Question (a)

Test 3 Final Question (a)

Re: T-Shape

Re: weak acids

Re: Question 4.45

Re: Question 4.29 [ENDORSED]

Re: Test 3 Q 8 [ENDORSED]

Re: shape of water

Re: 3.45 quick question

Shorter bond length always leads to stronger bond?

Re: Central atom

Re: Formaldehyde Formula

Re: Bond Dissociation

Re: Resonance Structures

Re: octect rule

Re: SO2

Re: Largest in Atomic Radii?

Re: Help on 2.43

Re: Help on 3.35

Test 2 Q4 help [ENDORSED]

How detailed should the configurations be?

Test 2 final question [ENDORSED]

equations that apply to light only/everything else but light

Re: Quiz 2 [ENDORSED]

Re: Confusion with the conclusion sentence of 1.15 in the solutions manual [ENDORSED]

Solving 1.11 [ENDORSED]

History of experiments on the model of atom

Data to memorize for this chapter [ENDORSED]

F.25

Re: Conversion rates [ENDORSED]

What is the notation for molar mass?