CHEMISTRY COMMUNITY

Esther Ahn 4I

Acids also tend to have the form HA where A is an element and bases tend to have the form BOH where B is an element.

Esther Ahn 4I

For the Ka formula, why is H30+ and H+ the same thing?

Esther Ahn 4I

You can determine the strength of an acid or base by finding the pKb and pKa of that base or acid. The smaller the pKb, the stronger the base. The larger the pKa, the stronger the corresponding conjugate base.
Also, the weaker the bond, the stronger the acid. Hope this helps!

Esther Ahn 4I

Dr. Lavelle mentioned that it is better to write it so that it is OH2 to show that the lone pairs on the oxygen is the one binding to the central atom. If it was written like H20 then it would make it seem like the H is interacting with the central atom which isn’t true. This is why we switch the or...

Esther Ahn 4I

For repulsion strength, lone-lone pair has the highest repulsion strength, then it is lone-bonding pair and the weakest is bonding-bonding pair. Therefore, the lone pair electron forces the bonding electron closer together. This causes the angle to be slightly smaller than expected.

Esther Ahn 4I

Just adding on, elements such as Carbon would have hybridization 2sp^2 and sp^2. Hydrogen would be 1s. Like mentioned above, the one with the 2 in front is just more specific and it allows you to figure out which element is being hybridized.

Esther Ahn 4I

Draw a Lewis Structure and examine the shape of the molecule. If the bonds are symmetrical and their polarities cancel each other out, then the molecule is non polar. If the bonds are asymmetrical and thus the more electronegative element is on one end and the electropositive element is on the other...

Esther Ahn 4I

Electron promotion is when an electron absorbs a photon to jump from a low energy level to a higher energy orbital. This is important because when bonds are formed, energy is released and then the system becomes more stable. Thus, atoms provide energy to promote an electron and this would make it in...

Esther Ahn 4I

I think it would just be hybridization and VSEPR models since that’s all we really covered after the midterm!

Esther Ahn 4I

Hi, sigma bonds are stronger than pi bonds. This means that the sigma bond will have higher energy because the s orbital overlaps over a greater area than the p orbital.

Esther Ahn 4I

The bonding electron is further from the central atom than a lone pair which is close to the nucleus (which is positively charged). Therefore, the VSEPR theory says that repulsion by the lone pair is greater than the repulsion by the bonding pair.

Esther Ahn 4I

In lecture Dr. Lavelle mentioned that although sulfite has 4 electron pairs arranged tetrahedrally the O-S-O bond angles are 106 degrees and not the expected 109.5 degrees. Can someone please explain why?

Esther Ahn 4I

It depends! If it’s a negative charge, you generally want to make sure that the most electronegative element will take this charge. You generally don’t want your central atom to take the charge, but if you really have to I think it’s better for it to take a positive charge than a negative formal cha...

Esther Ahn 4I

You can know bond lengths through dissociation energies. The strength of a bond is measured by its dissociation energy which is the energy required to break the bond. Stronger bonds are shorter bonds and weaker bonds are longer bonds. This is because larger atoms have larger bond lengths (more dista...

Esther Ahn 4I

More electrons means that these electrons will repel each other more, increasing the radius, increasing distortion and thus increasing polarizability!

Esther Ahn 4I

My TA told me that every bond (line) is counted as one and every lone pair is counted as two. So you would basically just count the number of lines and the number of dots and subtract it from the number of valence electrons!

Esther Ahn 4I

The question is: For the hydrogen atom which statement is true? A. The transition from n = 5 to n = 3 involves greater energy than one from n = 4 to n = 2. B. The transition from n = 4 to n = 2 emits radiation of longer wavelength than the transition from n = 5 to n = 1. C. All transitions from stat...

Esther Ahn 4I

Can someone explain to me why Xe and O share a double bond? Why does Oxygen just not get another lone pair of electrons? Why is it double bonded with Xe?

Esther Ahn 4I

I was just wondering how you would know what p-block element gains its electrons and what p-block element loses its electrons. Does it just depend on the element?

Esther Ahn 4I

Also, when an atom only contains a single electron (like a Hydrogen atom), if it has the same principle quantum number (n), then it is degenerate. For example, a 2s and a 2p orbital would be degenerate.

Esther Ahn 4I

Hi, I am having trouble figuring out how to solve this problem. 42. An excited hydrogen atom emits light with a frequency of 1.14 x 1014 Hz to reach the energy level n = 4. In what principle quantum level did the electron begin? I’m using E = hv since we are given frequency and solved for E at n = 4...

Esther Ahn 4I

The energy needed to remove an electron from one sodium atom is simply the work function converted to the right units(J/atom) You would have to multiply 150.6 kg/mol by 1000 to get 150.6*10^3 J/mol. Then you would divide that number by Avagadro's constant to get the answer 2.5*10^-19 J/atom. Why wo...

Esther Ahn 4I

Photoelectric experiments gave rise to a new equation relating the energy of light to its frequency. Select the right equation. A. λv = c B. Ek = mv2/2 C. mv2/2 = hv - φ D. E = hv E. None of the above I put C as my answer, but this was incorrect. Can someone tell me the correct answer and why that i...

Esther Ahn 4I

I put wave to photon model as well. Can someone please explain in more detail why particle is a better choice than photon because I thought this experiment was measuring the amount of energy of each photon.

Esther Ahn 4I

Can someone please explain why the units for a Joule are 1 kg*m^2/s^2 :) I’m just a bit confused as to where this is coming from.

Esther Ahn 4I

An easy way to remember conversions is The Great King Henry Died By Drinking Chocolate Milk. Tera, Giga, Kilo, Hecto, Deca, Base, Deci, Centi, Milli. You can see that because milli is three away from the base to the right, a mmol is 10^-3 mol.

Esther Ahn 4I

Hi, I was doing the homework for this week and for the question G5, we are required to know that sodium carbonate is Na2CO3. In the solutions manual though, for part b, this suddenly changes to Na2CO2. I was wondering if you guys think this is a typo or if this was intentional. Thanks!!

Esther Ahn 4I

You would use Avogadro’s number because 1 mol of an atom, molecule or formula unit contains 6.022 x 10^23 atoms! Hope this helps :)

Esther Ahn 4I

For question E1, you have to find how long the fibers extend, given that you string together 1.00 mol Ag atoms, each of a radius of 144pm. For my answer I got 8.67 x 10^13 m. The solution manual gives us the final answer in kilometers. I was just wondering why the answer is given in kilometers and n...

Esther Ahn 4I

I’m doing question E9 from Edition 6 and it asks me to calculate the molar mass of MgSo4 7H20. I used 1.00g/mol for the molar mass of hydrogen and got 246.37g/mol for the total molar mass of the salt. The solution manual says the answer is 246.48 g/mol for the total molar mass of the salt. You can g...

CHEMISTRY COMMUNITY

Search found 30 matches

Re: How to tell if it is an acid or base?

H30+ and H+

Re: Strength of an acid/base

Re: Aqua

Re: Lone pairs

Re: 2SP^3 vs. SP^3

Re: Polar vs Nonpolar

Re: promoted hybridization

Re: Test

Re: Differences in energy

Re: Repulsion Strength

Bond Angle of Sulfite Ion

Re: Poly-atomic Ions

Re: Bond Lengths

Re: Polarizability

Re: shortcut for FC

Post Module #41

6th Edition 3.65

P-block elements

Re: Degeneracy

Post Module Assessment #42

Re: Module Question 29 (Part B)

Post Module Assessment #25

Re: Photoelectric Effect Post Module Questions

Units for a Joule [ENDORSED]

Re: mol vs. mmol

Edition 6, G5 Question

Re: Formula Units??

Homework Question Edition 6 E1

Hydrogen Molar Mass HW E9