Search found 21 matches

by Sylvia_Cai_3D
Sun Mar 19, 2017 12:15 pm
Forum: *ChemDraw
Topic: Conformation drawings
Replies: 3
Views: 664

Re: Conformation drawings

Yes and at about 110 angle
by Sylvia_Cai_3D
Thu Mar 09, 2017 1:24 am
Forum: *Organic Reaction Mechanisms in General
Topic: Half arrows
Replies: 4
Views: 537

Re: Half arrows

You use the full arrows because two electrons from the Carbon bond are going to the halogen. Before the reaction the halogen has 3 lone pairs, which is 6 electrons and the Carbon and the halogen share electrons through a bond. During the reaction the electrons from the bond go to the halogen making ...
by Sylvia_Cai_3D
Thu Mar 09, 2017 1:20 am
Forum: *Organic Reaction Mechanisms in General
Topic: Standard Gibbs Free Energy of Activation
Replies: 4
Views: 690

Re: Standard Gibbs Free Energy of Activation

You would draw from the reactants to wherever the transition state lies respectively on the two transition states when it is asking for Gibbs Free Energy. When it asks for potential energy, then for the first transition state you would draw from the reactants to the transition state then at the seco...
by Sylvia_Cai_3D
Thu Mar 09, 2017 1:16 am
Forum: *Organic Reaction Mechanisms in General
Topic: Intro to Organic Chemistry HW Section 4.3 #29 and 30
Replies: 2
Views: 366

Re: Intro to Organic Chemistry HW Section 4.3 #29 and 30

I believe for #29 you know it is exergonic from previous examples in class and in the course reader since it was used/discussed multiple times.
by Sylvia_Cai_3D
Sun Feb 26, 2017 3:43 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7569
Views: 1011500

Re: Post All Chemistry Jokes Here

Q: What do chemists call a benzene ring with iron atoms replacing the carbon atoms?
A: A ferrous wheel.
by Sylvia_Cai_3D
Tue Feb 21, 2017 12:48 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7569
Views: 1011500

Re: Post All Chemistry Jokes Here

Q: Do you have any sodium hypobromite?
A: NaBrO
by Sylvia_Cai_3D
Thu Feb 09, 2017 3:47 pm
Forum: Balancing Redox Reactions
Topic: Textbook Question 14.3 D
Replies: 1
Views: 196

Re: Textbook Question 14.3 D

The oxidation number of Cl2 is 0 in the reactants. The oxidation number of Cl in HClO is +1 and the oxidation number of Cl in Cl- is -1. So the Cl2 can serving as both an oxidizing and reducing agent.
by Sylvia_Cai_3D
Mon Jan 30, 2017 1:43 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: 9.37
Replies: 2
Views: 342

Re: 9.37

This is because we are currently trying to find the entropy of formation rather than enthalpy of vaporization
by Sylvia_Cai_3D
Mon Jan 30, 2017 1:41 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Chapter 8 Number 77
Replies: 2
Views: 279

Re: Chapter 8 Number 77

the kekule structure is the structure where benzene is in a hexagon and the C's are all attached to each other by a bond (alternating single and double bonds) while there are H's attached to the C's.
by Sylvia_Cai_3D
Sat Jan 21, 2017 10:03 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Problem 8.51
Replies: 1
Views: 249

Re: Problem 8.51

Yes, you convert the density to liters, but included in the enthalpy value is the "per mole" part so you have to make the values' units match each other by changing the density value from grams to moles.
by Sylvia_Cai_3D
Sat Jan 21, 2017 9:57 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: HW Problem 8.67 Part A
Replies: 2
Views: 291

Re: HW Problem 8.67 Part A

H2O is not in an elemental form so it would not be 0.
by Sylvia_Cai_3D
Tue Nov 29, 2016 2:11 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: -CH3 electron donating property
Replies: 1
Views: 300

Re: -CH3 electron donating property

I think that -CH3 has higher electron donating power because -CH3 is a radical and radicals are highly reactive. A higher reactivity in a radical makes it lose the electron easily.
by Sylvia_Cai_3D
Tue Nov 29, 2016 12:15 am
Forum: Ideal Gases
Topic: Gas Constant Conversion Factors
Replies: 1
Views: 429

Re: Gas Constant Conversion Factors

1m^3 = 1000 L, which is why the value in the first R is 8.206x10^-2 whereas the value in the second R is 8.206x10^-5. The first value has the 1000 from the L multiplied into the 8.206x10^-5 which makes it 8.206x10^-2.
by Sylvia_Cai_3D
Sun Nov 20, 2016 1:17 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Fall 2016 Final Q7A
Replies: 1
Views: 197

Re: Fall 2016 Final Q7A

Acidosis is an excess of acid in the blood that causes the pH to fall below 7.35, and alkalosis is an excess of base in the blood that causes the pH to rise above 7.45. Excess CO2 and water makes H2CO3 which, in the presence of water, dissociates into H3O+ and HCO3- and the H3O+ makes the pH more ac...
by Sylvia_Cai_3D
Mon Nov 14, 2016 3:04 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Difference between VSEPR and MOT
Replies: 3
Views: 2578

Re: Difference between VSEPR and MOT

VESPR determines the shape of a molecule based on the number of electron pairs surrounding the central atom. MOT is also a way to determine molecular structure, but the electrons are not stuck in one bond, rather, they are spread out throughout the entire molecule. This is a more accurate representa...
by Sylvia_Cai_3D
Mon Nov 07, 2016 12:56 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Order
Replies: 2
Views: 526

Re: Bond Order

Bond order is the number of chemical bonds between a pair of atoms. So for example, C-H has a bond order of 1 because it has a single bond. A double bond has a bond order of 2 and a triple bond has a bond order of 3. So, yes, when the bond order is greater than 0 then it is stable because if it were...
by Sylvia_Cai_3D
Mon Oct 31, 2016 2:07 am
Forum: Octet Exceptions
Topic: Ground state
Replies: 2
Views: 306

Re: Ground state

Isoelectronic means that two elements have the same electron configuration so to answer your first question, the electron configuration of Vanadium is the same as that of Fe^3+. The definition of isoelectronic means having the same number of electrons so yes isoelectronic elements have the same elec...
by Sylvia_Cai_3D
Sun Oct 23, 2016 11:57 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Noble Gases and Electron Affinity
Replies: 3
Views: 489

Re: Noble Gases and Electron Affinity

Yeah, you're right the trend doesn't apply to noble gases because they do not have an affinity for electrons.
by Sylvia_Cai_3D
Sun Oct 16, 2016 4:22 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Chapter 2 HW: #39 [ENDORSED]
Replies: 7
Views: 1454

Re: Chapter 2 HW: #39 [ENDORSED]

The answer is (d). The question is asking which electron configuration correctly corresponds to the element next to it. (a) is wrong because of Hund's Rule; due to e- repulsion, the e- should occupy different orbitals first. (b) is wrong because in each orbital, the up arrow spin should go in first ...
by Sylvia_Cai_3D
Sun Oct 09, 2016 11:57 am
Forum: Properties of Light
Topic: HW Question Ch #27 [ENDORSED]
Replies: 5
Views: 912

Re: HW Question Ch #27 [ENDORSED]

I had a similar question, but I am still confused about how it is 6.022X10^23 photons per mole. Is it just a known constant that just like atoms there are a certain number of photons per mole?
by Sylvia_Cai_3D
Wed Oct 05, 2016 9:17 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Hydrogen Spectrum
Replies: 3
Views: 472

Re: Hydrogen Spectrum

The next on is 397.0 nm

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