Search found 19 matches

by Yifei Wang 3G
Wed Dec 06, 2017 3:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Dipole Moment
Replies: 2
Views: 374

Re: Dipole Moment

try to look at the geometry of the molecule. From the structure, you can see the lone pair is occupying more space than a bond would, therefore the angle is slightly altered and the dipole moment cannot cancel out.
by Yifei Wang 3G
Wed Dec 06, 2017 3:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: How to assume X is too small
Replies: 3
Views: 227

Re: How to assume X is too small

Normally in a reaction with extremely small K, we can apply the 5% rule, but make sure that the answer is less than 5% of the original concentration
by Yifei Wang 3G
Sat Dec 02, 2017 2:31 pm
Forum: Bronsted Acids & Bases
Topic: Identifying Bronsted Acids and Bases [ENDORSED]
Replies: 3
Views: 211

Re: Identifying Bronsted Acids and Bases [ENDORSED]

we can tell from the chemical equation, which are usually given in the problems. If from the left to the right, a reactant loses H+, it is the Bronsted acid. If from the left to the right, a reactant gains H+, it is the Bronsted base.
by Yifei Wang 3G
Sat Dec 02, 2017 2:20 pm
Forum: Administrative Questions and Class Announcements
Topic: chemistry community posts [ENDORSED]
Replies: 1
Views: 141

Re: chemistry community posts [ENDORSED]

you can go to the "Quick links" and click on "your posts" to see all your previous posts
by Yifei Wang 3G
Tue Nov 28, 2017 11:08 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Dentates
Replies: 1
Views: 148

Re: Dentates

I suppose you just have to remember the polydentate-ligands specifically indicated in the charts. I don't think we would be asked to draw them.
by Yifei Wang 3G
Tue Nov 28, 2017 11:06 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc vs. Kp
Replies: 3
Views: 219

Re: Kc vs. Kp

when the problem only involves aq, K must be calculated from molar concentrations of the reactants and the products. when the problem involves both g and aq, you also have to use concentrations for all the things because aq can only have concentration while g can have both concentration and partial ...
by Yifei Wang 3G
Fri Nov 24, 2017 2:18 pm
Forum: Naming
Topic: The number of coordinate covalent bonds
Replies: 1
Views: 128

The number of coordinate covalent bonds

In a coordinate compound,should the number of coordinate covalent bonds always be 6? Also does it mean that the geometry of the compound should always be octahedral?
by Yifei Wang 3G
Sun Nov 19, 2017 1:45 pm
Forum: Naming
Topic: Question about the number of hydration
Replies: 1
Views: 155

Question about the number of hydration

if the coordinate complex is followed by an anion and a hydration part, how do we determine the number of H2O?
and if the complex is followed by an cation or just exist by itself in water, would there still be hydration?
by Yifei Wang 3G
Fri Nov 17, 2017 9:19 pm
Forum: Hybridization
Topic: Difference between sigma and pi bonds?
Replies: 6
Views: 712

Re: Difference between sigma and pi bonds?

sigma and pi bonds are associated with the electron density and how the electrons interact with each other. A sigma bond is formed by the pairing of electron spins in two atomic orbitals on neighboring atoms. sigma bonds are cylindrically symmetrical and they contribute towards an overlap or mergin...
by Yifei Wang 3G
Thu Nov 09, 2017 12:10 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Relationship between Orbitals and Properties of Electrons
Replies: 2
Views: 142

Re: Relationship between Orbitals and Properties of Electrons

I guess basically "the properties" means energy of the electron and movement of the electron (related to quantum numbers n, l, ml, ms)
by Yifei Wang 3G
Thu Nov 09, 2017 12:06 pm
Forum: Dipole Moments
Topic: Midterm [ENDORSED]
Replies: 5
Views: 364

Re: Midterm [ENDORSED]

the outline mentioned dipole moment, so I guess it's possible to be on the test. We just have to remember that when we draw it, the arrow is always pointing to the atom that has higher electronegativity.
by Yifei Wang 3G
Sun Nov 05, 2017 11:47 pm
Forum: *Particle in a Box
Topic: Homework Problem 1.48
Replies: 2
Views: 438

Homework Problem 1.48

I don't quite get what the problem is asking and which equation to use to solve it. Can anyone explain it?
by Yifei Wang 3G
Sat Oct 28, 2017 6:27 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Magnetic Quantum Numbers [ENDORSED]
Replies: 6
Views: 423

Re: Magnetic Quantum Numbers [ENDORSED]

Matt_Fontila_3L wrote:If, however, you were talking about the Spin Magnetic Quantum Number, the positive or negative in front of the 1/2 is the most important part in determining which way the electron is spinning.

No not the spin. I was asking about the Magnetic Quantum Number, ml. But your answer is also helpful!
by Yifei Wang 3G
Fri Oct 20, 2017 3:01 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Magnetic Quantum Numbers [ENDORSED]
Replies: 6
Views: 423

Magnetic Quantum Numbers [ENDORSED]

A Magnetic Quantum Number can be positive or negative, but what does the positive/negative symbol mean for it?
by Yifei Wang 3G
Fri Oct 20, 2017 2:55 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 4s to 3d
Replies: 5
Views: 283

Re: 4s to 3d

Overall the energy of electrons in the 3rd shell is lower than that of electrons in the 4th shell, but when it comes to the specific subshells, it's a different story. When comparing 4s and 3d, 4s indeed has lower energy.
by Yifei Wang 3G
Sun Oct 15, 2017 12:03 am
Forum: *Black Body Radiation
Topic: Black body for quiz 2 [ENDORSED]
Replies: 11
Views: 802

Re: Black body for quiz 2 [ENDORSED]

Actually test 2 covers Chapter 1 up to the end of section 1.5. Black body and wien's law are in 1.4 so they maybe will appear in test 2
by Yifei Wang 3G
Fri Oct 06, 2017 9:42 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical Coefficients [ENDORSED]
Replies: 12
Views: 852

Re: Empirical Coefficients [ENDORSED]

nanditasundarapandian1D wrote:From what I learned you round up when its bigger than .5 and round down when its smaller than .5

but what if the last digit is exactly 5?
by Yifei Wang 3G
Fri Oct 06, 2017 3:28 pm
Forum: Empirical & Molecular Formulas
Topic: Friday Oct 6 Test
Replies: 7
Views: 488

Re: Friday Oct 6 Test

Here's how I worked out this problem: 1. apply the Law of Conservation of Mass to find out the mass of O2 in reactant 2. calculate the moles of X, O2, CO2, and H2O 3. find out the net molar ratio of C, H, and O (subtract the moles of O from the reactant O2) of the products, which in turn should be t...

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