Search found 33 matches

by Sheel Shah 1H
Sat Dec 09, 2017 8:07 pm
Forum: Conjugate Acids & Bases
Topic: 12.131
Replies: 1
Views: 266

12.131

Hey!! I really don't understand question 131 --> it deals with the reaction H3O+ + HbO2- --> HHb + H2O + O2-, regarding hemoglobin and oxygen release. The first q is a) What effect will the lactic acid have on the concentration of HbO2-? b) When hemoglobin returns to the lungs, where oxygen concentr...
by Sheel Shah 1H
Fri Dec 08, 2017 9:42 pm
Forum: Administrative Questions and Class Announcements
Topic: GRADING
Replies: 1
Views: 165

GRADING

Hey there!

I was wondering what score out of 500 you would need to get an A! I've heard that the grades are determined at the end, but if you have slightly less than a raw 93 are you still good to get an A?

Thanks!
by Sheel Shah 1H
Tue Dec 05, 2017 12:27 pm
Forum: Air Pollution & Acid Rain
Topic: compounds for acid rain
Replies: 3
Views: 511

Re: compounds for acid rain

Basically any compound that can react with water to form an acid can result in acid rain. Ex. CO2+H20 forms H2CO3 (carbonic acid), but this is just one of many common examples, which can follow a similar reaction pattern.
by Sheel Shah 1H
Tue Dec 05, 2017 12:26 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: 5% rule
Replies: 2
Views: 267

Re: 5% rule

Exactly what the above response said; however, another useful tool you could use is if the Ka/Kb value is less than 10x10^-3, it is generally safe to assume the change in x as negligible (for the initial reactant). This is NOT to say that x=0, it still changes by some amount, just an incredibly smal...
by Sheel Shah 1H
Tue Dec 05, 2017 12:23 pm
Forum: Conjugate Acids & Bases
Topic: Conjugate Acid and Base
Replies: 5
Views: 278

Re: Conjugate Acid and Base

@Essly Medoza A conjugate acid is the ionized form of a base (with the hydrogen added to it giving it acidic properties); a weak acid is simply an acid as the original reactant which has a low dissociation value (it does not readily ionize in solution, so it has a low Ka value). Similarly a conjugat...
by Sheel Shah 1H
Mon Nov 27, 2017 12:32 pm
Forum: Hybridization
Topic: Numbers in front of hybrid orbitals [ENDORSED]
Replies: 2
Views: 187

Numbers in front of hybrid orbitals [ENDORSED]

Hey there!

I was just wondering what exactly is meant by the number in front of the hybrid orbital name? Ex. what is meant by 2sp3 vs sp3? Does these two notations have different forms/orbital shapes, or are they just a method of clarifying which energy level the hybrid orbital is on?

Thanks!! :)
by Sheel Shah 1H
Mon Nov 27, 2017 12:30 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: EDTA and Bonding Sites [ENDORSED]
Replies: 5
Views: 379

Re: EDTA and Bonding Sites [ENDORSED]

I believe the former response meant to say "polydentate," which essentially means that the ligand can bond to two or more bonding sites simultaneously. EDTA has six bonding sites making it a hexadentate ligand; it can bond at up to six bonding sites simultaneously. This is of great importa...
by Sheel Shah 1H
Mon Nov 27, 2017 12:27 pm
Forum: Naming
Topic: Naming with an anionic complexes [ENDORSED]
Replies: 1
Views: 176

Naming with an anionic complexes [ENDORSED]

Hey!

How do we know when to use the latin name for the central metal atom when naming coordination compounds where the complex is anionic? For example, how do we know to use ferrate for ion, versus platinate for platinum?

Thanks!! :)
by Sheel Shah 1H
Mon Nov 20, 2017 11:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Temperature in Kp measurements
Replies: 2
Views: 149

Temperature in Kp measurements

Why does temperature affect Kp calculations? Does the rate constant increase or decrease as temperature increases? Does the effect of temperature on K vary to its degree for different chemical reactions?
by Sheel Shah 1H
Mon Nov 20, 2017 11:01 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Rate Constant Clarification
Replies: 1
Views: 103

Rate Constant Clarification

When solving for a rate constant with both aqueous and gaseous products as reactants/products, would we have to use the ideal has law to convert all the reactants to concentration and then solve for Kc? Or can we just use both partial pressures and concentrations together in one concentration to sol...
by Sheel Shah 1H
Mon Nov 20, 2017 10:58 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium
Replies: 3
Views: 324

Re: Equilibrium

Yes, exactly. You would only include liquids and aqueous solutions in the rate constant calculation.
by Sheel Shah 1H
Thu Nov 16, 2017 2:38 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Angles
Replies: 8
Views: 430

Re: Bond Angles

You just need to know that a lone electron pair causes the bond angle between the central atom and other atoms to decrease slightly. Ex. CH4 has bond angles of 109.5 degrees but ammonia (NH3) has bond angles slightly less than 109.5 degrees. You do not need to know the exact bond angle of ammonia.
by Sheel Shah 1H
Thu Nov 16, 2017 2:36 pm
Forum: Hybridization
Topic: the number of pi bonds
Replies: 3
Views: 177

Re: the number of pi bonds

The Pi bonds are essentially formed when two unhbyridized p orbitals interact vertically and restrict movement around the double bond. The unbhtbridized p orbitals are responsible for the Pi bonds in benezene in this case.
by Sheel Shah 1H
Thu Nov 16, 2017 2:34 pm
Forum: Hybridization
Topic: What is a hybrid orbital?
Replies: 2
Views: 180

Re: What is a hybrid orbital?

A hybrid orbital is simply a combination of two orbitals in which the electrons of each are shared by both orbitals at a lower energy level, when a bond forms. For example the s orbital would typically hold 2 electrons and the p electron could hold a maximum of six. An sp hybrid orbital orbital coul...
by Sheel Shah 1H
Tue Nov 07, 2017 10:33 pm
Forum: Properties of Light
Topic: Velocity [ENDORSED]
Replies: 13
Views: 706

Re: Velocity [ENDORSED]

velocity is the absolute value of speed in calculus terms; essentially speed simply analyses magnitude whereas velocity takes into account both magnitude and direction. Velocity is a vector and speed is a scalar. These details are more important in physics and will not play a crucial role in analyzi...
by Sheel Shah 1H
Tue Nov 07, 2017 10:31 pm
Forum: Resonance Structures
Topic: Delocalized electrons
Replies: 4
Views: 239

Re: Delocalized electrons

Delocalized electrons are basically shared by the resonance molecule. For example in benzene, the electrons are shared EQUALLY within all 6 carbon atoms, allowing the molecule to attain its most stable structure.
by Sheel Shah 1H
Tue Nov 07, 2017 10:29 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge and stability [ENDORSED]
Replies: 7
Views: 2533

Re: Formal Charge and stability [ENDORSED]

A really easy way to think about this concept of formal charge and stability is that you want to attain the lowest formal charge for a given lewis structure, because the one with the lowest formal charges is the most stable. In general, structures prefer to be as stable as possible, and you want to ...
by Sheel Shah 1H
Wed Nov 01, 2017 5:13 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodes
Replies: 4
Views: 313

Re: Nodes

electrons will not occupy the values at nodes
by Sheel Shah 1H
Wed Nov 01, 2017 5:11 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: **HW: 2.55
Replies: 1
Views: 157

**HW: 2.55

Hi there, for the following question: "Give the notation for the valence-shell configuration (including the outermost d-electrons) of the [...] c) Group 5 transition metals" why is the answer not (n-1)d^3 ns^2? The book says it is (n-1)d^5 ns^2 and i can't seem to understand why? Thanks fo...
by Sheel Shah 1H
Wed Nov 01, 2017 12:29 am
Forum: Trends in The Periodic Table
Topic: Noble Gas Electron Affinity
Replies: 3
Views: 530

Noble Gas Electron Affinity

Why do the noble gases not follow any trend in electron affinity. I understand that they would require energy to add an electron to an already stable octet (adding to a new shell), but shouldn't a trend WITHIN the gases still hold?
by Sheel Shah 1H
Wed Nov 01, 2017 12:27 am
Forum: Trends in The Periodic Table
Topic: Homework Problem 2.93
Replies: 1
Views: 132

Homework Problem 2.93

The question depicts a reaction between a sodium atom and chlorine atom using illustrations and asks you to determine which molecule is each a)sodium atom b)chlorine atom c)sodium ion d)chlorine ion. The question itself is quite self-explanatory, but I believe the answer in the book is wrong or I ma...
by Sheel Shah 1H
Tue Oct 24, 2017 11:54 pm
Forum: *Shrodinger Equation
Topic: Using Shrodinger's Equation
Replies: 4
Views: 435

Using Shrodinger's Equation

Hey there, For the upcoming quantum test (ch1+2) do we need to know how to use/derive shrodinger's wave equation? I understand the general conclusions of it, as well as how it applies to the quantum unit (and quantum numbers), but every sample problem in the book seems to be centered on the complex ...
by Sheel Shah 1H
Tue Oct 24, 2017 11:51 pm
Forum: *Particle in a Box
Topic: Deriving the equation
Replies: 1
Views: 324

Deriving the equation

Hey there, I noticed in the textbook (page 21) they showed us how to derive the above equation. The book goes from an explanation of how L=1/2 lambda, 2/2 lambda etc to lambda=2L/n. How did they get to this step? I am really confused on how to derive this equation - do we need to know it for the upc...
by Sheel Shah 1H
Tue Oct 17, 2017 8:23 pm
Forum: DeBroglie Equation
Topic: CHAPTER 1 QUESTION 33!!!
Replies: 8
Views: 432

Re: CHAPTER 1 QUESTION 33!!!

The photon that causes the electron to be ejected off does not have the same wavelength. So if you are calculating using E = hv you are calculating the wavelength for the incoming photon not the ejected electron, whereas when you use De Broglie's equation you are calculating the wavelength of the e...
by Sheel Shah 1H
Tue Oct 17, 2017 8:20 pm
Forum: DeBroglie Equation
Topic: CHAPTER 1 QUESTION 33!!!
Replies: 8
Views: 432

Re: CHAPTER 1 QUESTION 33!!!

but dont photons have mass as well?
by Sheel Shah 1H
Tue Oct 17, 2017 8:17 pm
Forum: DeBroglie Equation
Topic: 1.39 Help
Replies: 5
Views: 324

Re: 1.39 Help

Are we expected to know the conversion from miles to kilometres? It's not on the equation and constant sheet either!
by Sheel Shah 1H
Tue Oct 17, 2017 7:55 pm
Forum: Einstein Equation
Topic: Use of symbols
Replies: 6
Views: 654

Re: Use of symbols

It is standard convention for frequency to be defined by v as it is, but if you indicate your dilemma to your TA and write it at the top of your page there shouldn't be any reason for concern!

All the best!
by Sheel Shah 1H
Tue Oct 17, 2017 7:50 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation! [ENDORSED]
Replies: 8
Views: 643

Re: Rydberg Equation! [ENDORSED]

The reason why your E is negative is because energy is being RELEASED! Similar to how in physics a negative value in front of acceleration represents something is going DOWN, here it is simply indicative of a release of energy. You can calculate the change in E and use that for subsequent calculatio...
by Sheel Shah 1H
Tue Oct 17, 2017 7:47 pm
Forum: DeBroglie Equation
Topic: CHAPTER 1 QUESTION 33!!!
Replies: 8
Views: 432

CHAPTER 1 QUESTION 33!!!

Q: The velocity of an electron that is emitted from a metallic surface by a photon is 3.6x10^3 km/s. a) What is the wavelength of the ejected electron. I get the correct answer, 2.02x10^-10m, when I use de Broglie's equation; however, I cannot understand why we can't get the same answer if we calcul...
by Sheel Shah 1H
Mon Oct 09, 2017 4:42 pm
Forum: Properties of Light
Topic: Exited state
Replies: 5
Views: 333

Re: Exited state

Hi there, Electrons, like most objects, have a tendency to return to a more stable ground level. It is not possible for electrons to remain in the excited state as it is an UNSTABLE state, which they will always return from. You can think of its as analogous to "what goes up, must come down,&qu...
by Sheel Shah 1H
Mon Oct 09, 2017 4:38 pm
Forum: Properties of Light
Topic: Plank's Constant
Replies: 1
Views: 191

Plank's Constant

Hi there,

I was wondering what exactly Planck's constant is, and how it is used?

Thanks in advance,
Sheel Shah
by Sheel Shah 1H
Tue Oct 03, 2017 10:08 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Terminology Clarfication [ENDORSED]
Replies: 7
Views: 926

Re: Terminology Clarfication [ENDORSED]

Cu (I) has one positive charge, whereas Cu (II) has two positive charges. This is very important to know, especially when you are trying to find the formula for a specific compound (since the overall charge must always balance out). These types of metals are called "multivalent metals" bec...
by Sheel Shah 1H
Tue Oct 03, 2017 10:05 pm
Forum: Significant Figures
Topic: Significant Figures involving constants
Replies: 2
Views: 398

Re: Significant Figures involving constants

I would use the one provided with list of equations, just because it has been measured to increased accuracy, and you may be expected to do the same. I would also look for what other values in the question have been rounded off to. For example, if all the values in a question have 3 significant figu...

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