Search found 31 matches

by Yilun Ding
Tue Jul 30, 2019 11:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Angles
Replies: 2
Views: 143

Re: Angles

Yes!
by Yilun Ding
Fri Jul 26, 2019 7:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Why is AX3E2 linear?
Replies: 8
Views: 307

Re: Why is AX3E2 linear?

It actually a T- shaped molecule.
by Yilun Ding
Fri Jul 26, 2019 3:48 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7726
Views: 1044225

Re: Post All Chemistry Jokes Here

A joke about Helium.
by Yilun Ding
Fri Jul 26, 2019 3:47 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7726
Views: 1044225

Re: Post All Chemistry Jokes Here

A joke about photon.
by Yilun Ding
Fri Jul 26, 2019 3:13 pm
Forum: Naming
Topic: Fe------ferrate? [ENDORSED]
Replies: 8
Views: 399

Re: Fe------ferrate? [ENDORSED]

Cyanido is the new name for cyanide, also, when the complex is negatively charged, the metal cation will need to add ate. Iron is an exception that it will change its name to ferrate.
by Yilun Ding
Fri Jul 26, 2019 3:09 pm
Forum: General Science Questions
Topic: Final Material
Replies: 3
Views: 397

Re: Final Material

No.
by Yilun Ding
Fri Jul 26, 2019 3:05 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Oxidation states
Replies: 5
Views: 227

Re: Oxidation states

By reference to the periodic table, the Group 1 metals are more likely to lose an electron to become octet, then it has +1 oxidation state. However, because of relatively high ionization energy, the Group 7 non-metals will not lose electrons, instead, they usually gain an electron to become octet. T...
by Yilun Ding
Fri Jul 26, 2019 2:58 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Naming coordination compounds
Replies: 3
Views: 181

Re: Naming coordination compounds

I think we should remember them.
by Yilun Ding
Wed Jul 24, 2019 11:27 pm
Forum: Hybridization
Topic: homework 2.45 7th edition
Replies: 1
Views: 179

Re: homework 2.45 7th edition

There is a double bond which consists of a pi and a sigma bonds present in C and O. For the sigma bond, since there are three electron densities, its hybirdization should be C2sp2-O2sp2. For the pi bond, since there is a unused electron in its 2p orbital, it will form a pi bond with C2p and O2p.
by Yilun Ding
Wed Jul 24, 2019 5:20 pm
Forum: Administrative Questions and Class Announcements
Topic: Final
Replies: 4
Views: 256

Re: Final

Some questions in the final may come from the homework, like midterm.
by Yilun Ding
Wed Jul 24, 2019 5:14 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: edta
Replies: 8
Views: 542

edta

How many bonds can an edta ligand bond to a metal cation?
by Yilun Ding
Tue Jul 23, 2019 7:47 pm
Forum: Dipole Moments
Topic: Effect of size [ENDORSED]
Replies: 7
Views: 528

Re: Effect of size [ENDORSED]

This is because that increase the molecular mass will increase the number of electrons present in a molecule, its electron clouds will be more likely to be distorted(polariziability) which will lead to greater attraction.
by Yilun Ding
Tue Jul 23, 2019 7:38 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: name of molecule structure
Replies: 4
Views: 330

Re: name of molecule structure

First, we count the electron densities which is 5 (4 bonding pairs and 1 lone pair). It has the electron geometry of trigonal bipyramidal. However, instead having this structure, having 4 bonding pairs and 1 lone pair is called seesaw.
by Yilun Ding
Tue Jul 23, 2019 7:33 pm
Forum: Ionic & Covalent Bonds
Topic: Dipoles
Replies: 7
Views: 400

Re: Dipoles

Only polar bonds have dipoles, and only dipoles form the hydrogen bonds will form.
by Yilun Ding
Tue Jul 23, 2019 2:53 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7726
Views: 1044225

Re: Post All Chemistry Jokes Here

Heisenberg was caught speeding. The cops pulled him over and asked "do you know how fast you were going? " Heisenberg says "No, but I can tell you exactly where I was!" The cops were like " you were going 120 mph in 80 mph zone!" Heisenberg says " Great! Now I am l...
by Yilun Ding
Tue Jul 23, 2019 2:47 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7726
Views: 1044225

Re: Post All Chemistry Jokes Here

never trust atoms, they make up everything.
by Yilun Ding
Tue Jul 23, 2019 2:46 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7726
Views: 1044225

Re: Post All Chemistry Jokes Here

When a chemist dies, they barium.
by Yilun Ding
Tue Jul 23, 2019 2:27 pm
Forum: Lewis Structures
Topic: Problem 2E13 (7th edition) part d
Replies: 1
Views: 170

Re: Problem 2E13 (7th edition) part d

Both answers are acceptable since both models have total electrons of 16, and each atoms in both models is being octet. I am not sure about which one has the priority, but in the case of formal charge, both central atom N have formal charge of +1 ,the first model has a -1 charge on oxygen and the se...
by Yilun Ding
Tue Jul 23, 2019 2:14 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Test 2
Replies: 1
Views: 196

Re: Test 2

For the molecule on the left, each nitrogen atom with lone pair can form hydrogen bond with water, also each hydrogen bonded with nitrogen with partial positive charge (due to the electronegativity) will form hydrogen bond with oxygen atom in water. There are 5 nitrogen atoms with lone pair and part...
by Yilun Ding
Mon Jul 22, 2019 10:04 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Rotations and Shape
Replies: 4
Views: 269

Re: Rotations and Shape

No, we don't have to know.
by Yilun Ding
Sun Jul 21, 2019 5:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 3
Views: 102

Re: Bond Angles

We need to identify the shape by using the models mentioned in class. For centain type of model, we have to name the angles of its typical examples. Therefore, we should be able to name the shape and some basic angles.
by Yilun Ding
Sun Jul 21, 2019 5:25 pm
Forum: Hybridization
Topic: Determining how many electron densities
Replies: 5
Views: 173

Re: Determining how many electron densities

A lone pair is also an electron density. Therefore, a molecule with 3 bonding pairs and 1 lone pair should have 4 electron densities.
by Yilun Ding
Sun Jul 21, 2019 5:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar v. Nonpolar
Replies: 11
Views: 282

Re: Polar v. Nonpolar

First, a polar molecule must contain polar bonds. Then, if all polar bonds can cancel out it can be a nonpolar molecules, if cannot, it will become a polar molecule. To figure out whether all the dipoles can cancel out completely, you can use a vector diagram to see it clearly.
by Yilun Ding
Sun Jul 21, 2019 5:19 pm
Forum: Hybridization
Topic: Pi and Sigma Bonds
Replies: 17
Views: 299

Re: Pi and Sigma Bonds

For a double bond, there will be one pi and one sigma, and one triple bond consists of two pi bonds and one sigma bond.
by Yilun Ding
Mon Jul 15, 2019 3:30 pm
Forum: Lewis Structures
Topic: Ionic Bond Structures [ENDORSED]
Replies: 2
Views: 271

Re: Ionic Bond Structures [ENDORSED]

I think that the lewis structure cannot be used to demostrate the ionic bond because the "-----" represents the sharing of electrons (it is the characteristic of the covalent bonding). However, we can still use the dots in lewis diagram to represents gaining or losing electrons for ions.
by Yilun Ding
Mon Jul 15, 2019 9:24 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizing Power [ENDORSED]
Replies: 8
Views: 438

Re: Polarizing Power [ENDORSED]

Polarizing power is determined by the strength which a cation distorts the electron clould in the anion, and with greater polarizing power, that ionic compound would have more covalent characteristics.
by Yilun Ding
Tue Jul 09, 2019 10:25 pm
Forum: Properties of Light
Topic: VIdeo Module: Photoelectric effect question
Replies: 2
Views: 255

Re: VIdeo Module: Photoelectric effect question

In this case, the kinetic energy can just be calculated from 1/2mv2 since we already have velocity and mass (from the constant booklet)
by Yilun Ding
Tue Jul 09, 2019 10:17 pm
Forum: Molarity, Solutions, Dilutions
Topic: Test 1 number 7
Replies: 4
Views: 2143

Re: Test 1 number 7

Using the mass to calculate the moles of cisplatin first, then use the moles to divide the molarity ti get the volume. Next time you can figure out the relations by units.
by Yilun Ding
Fri Jun 28, 2019 11:11 am
Forum: SI Units, Unit Conversions
Topic: Limiting Reactants
Replies: 5
Views: 257

Re: Limiting Reactants

I believe that the professor doesn’t expect us to know in our course, but after we learn these compounds, the name should be known
by Yilun Ding
Fri Jun 28, 2019 11:07 am
Forum: SI Units, Unit Conversions
Topic: Use of Kelvin
Replies: 6
Views: 309

Re: Use of Kelvin

It is the lowest temperature we can reached

Go to advanced search