Search found 33 matches

by Michele Shi 1K
Sat Dec 09, 2017 10:20 pm
Forum: Conjugate Acids & Bases
Topic: 12.59(b) naming conjugate acid
Replies: 1
Views: 270

12.59(b) naming conjugate acid

When writing the conjugate acid of the base NH2OH, the solution manual says it is NH3OH. When do I know to add the H to the first H? Is it incorrect if I write NH2OH2?
by Michele Shi 1K
Sat Dec 09, 2017 9:14 pm
Forum: Lewis Acids & Bases
Topic: 12.51 comparing strengths of acids
Replies: 1
Views: 215

12.51 comparing strengths of acids

Problem 12.51 part (a) asks to compare strengths of HF and HCL. HCL is stronger because Cl has a larger atomic radius. However, for part (c), HBrO2 vs HClO2, HClO2 is stronger than HBrO2 because Cl is more electronegative. Why isn't HBrO2 stronger? In the case of HF and HCl, atomic radius was consid...
by Michele Shi 1K
Sat Dec 09, 2017 5:05 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.33 question
Replies: 1
Views: 193

12.33 question

For problem 12.33, can someone explain why the "original solution" (part b) has volume of 5 ml? wasnt it supposed to be 200ml?
by Michele Shi 1K
Sat Dec 09, 2017 4:21 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: [H30+] and [OH-] for strong acids/bases
Replies: 1
Views: 213

[H30+] and [OH-] for strong acids/bases

For reactions with strong acids or bases, does the concentration of the strong acid or base equal the concentration of [H30+] (for acids) and [OH-](for bases)??? Thank you!
by Michele Shi 1K
Sat Dec 09, 2017 11:16 am
Forum: Naming
Topic: SO4(2-) vs OSO3(2-)
Replies: 1
Views: 283

SO4(2-) vs OSO3(2-)

Is it incorrect if we write one over the other? I understand for NO2- vs ONO- because that is nitro vs nitrito. But for SO4(2-) and OSO3(2-), there are not different names. Thanks!
by Michele Shi 1K
Sat Dec 09, 2017 11:06 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Sits vs shifts left/right
Replies: 1
Views: 253

Sits vs shifts left/right

Does "the reaction sits to the left" and "the reaction shifts left" mean the same thing? I know that shifting left means the reverse reaction is favored.
by Michele Shi 1K
Fri Dec 08, 2017 12:04 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: If K is large or small
Replies: 1
Views: 155

If K is large or small

In lecture, we wrote: "if k is small (<10^-3), equilibrium sits to the left." does this mean that the the forward reaction is favored since there is more reactants than products?
by Michele Shi 1K
Thu Dec 07, 2017 10:37 pm
Forum: Hybridization
Topic: Sigma/Pi bond notation
Replies: 1
Views: 271

Sigma/Pi bond notation

Can someone please explain the notation for sigma or pi bonds? for example, σ(C2sp2,C2sp2) or something like that. THank you!
by Michele Shi 1K
Thu Dec 07, 2017 10:02 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Different Shapes
Replies: 4
Views: 568

Re: Different Shapes

Just realized we learned square planar too. That example was XeF4
by Michele Shi 1K
Thu Dec 07, 2017 9:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Different Shapes
Replies: 4
Views: 568

Different Shapes

I have list of shapes that we have gone over. please let me know if theres one missing!
linear, bent/angular, trigonal planar, tetrahedral, trigonal bipyramidal, octahedral, Tshaped, seesaw, square pyramidal.
What are the AXE formulas for Tshaped vs seesaw vs square pyramidal?
by Michele Shi 1K
Thu Nov 30, 2017 11:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 11.43
Replies: 1
Views: 200

11.43

Consider the reaction 2NO2(g) <>2NO(g) + O2(g)
If initial partial pressure of NO2(g) is 1.0 bar, and x is the equilibrium concentration of N2(g), what is the correct equilibrium relation?

Can someone please explain how to set this up? Does this problem use the ICE box thing?
by Michele Shi 1K
Thu Nov 30, 2017 1:35 pm
Forum: Dipole Moments
Topic: Determining polar or non polar: 4.27
Replies: 2
Views: 337

Determining polar or non polar: 4.27

Can someone explain the process on how to determine if these molecules are polar or non polar? The molecules in the problem are C5H5N, C2H6,CHCL3
by Michele Shi 1K
Thu Nov 30, 2017 1:17 pm
Forum: Lewis Structures
Topic: Lewis Structure of IO2F2 (-2) Problem 4.23 [ENDORSED]
Replies: 3
Views: 3914

Lewis Structure of IO2F2 (-2) Problem 4.23 [ENDORSED]

The solution manual says that lewis structure of IO2F2 (-2) is with I as the central atom and single bonds each connecting to the 2 O atoms and 2 F atoms. Is it OK if i create a double bond with the oxygen atoms so then the formal charge of those are 0? Or do I have to keep only single bonds? Thanks
by Michele Shi 1K
Wed Nov 29, 2017 11:54 pm
Forum: Naming
Topic: aqua = (OH2) or (H20)
Replies: 2
Views: 259

aqua = (OH2) or (H20)

When naming [Co(CN)5(OH2)], why is OH2 (aqua) written like that? (Aquapentacyanocobaltate(III))
There was another problem where you write the compound given the name "tetraamminediaquacobalt (III)bromide". The answer had aqua written like (H20)2..
by Michele Shi 1K
Wed Nov 29, 2017 4:31 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.13 d
Replies: 1
Views: 172

4.13 d

The lewis structure for N20 has the central atom of N instead of O. I thought that there had to be symmetry. Can someone explain why the N is central? Thank you!
by Michele Shi 1K
Wed Nov 29, 2017 4:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.11 c [ENDORSED]
Replies: 1
Views: 176

4.11 c [ENDORSED]

The compound IF4- has a molecular structure where the lone pairs are opposite of each other and there are 2 Fluorine atoms on the left and right of the central atom. Why aren't the lone pairs both together and pushing the 4 other regions of electron density? For part b of 4.11, the two lone pairs go...
by Michele Shi 1K
Wed Nov 29, 2017 3:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: more about problem 4.9 [ENDORSED]
Replies: 1
Views: 179

more about problem 4.9 [ENDORSED]

The shape of ICl3 is Tshaped and from other students explaining, it is because 2 of the 5 regions of electron density are taken up by lone pairs. Someone said that the lone pairs are on the equitorial axis but why wouldn't they just be on the 2 axial regions therefore making it trigonal planar? It i...
by Michele Shi 1K
Sun Nov 26, 2017 8:58 pm
Forum: Hybridization
Topic: D orbital
Replies: 2
Views: 208

Re: D orbital

I dont believe that we need to know how to draw them. but it is helpful to have some sort of idea about how they look
by Michele Shi 1K
Sun Nov 26, 2017 8:57 pm
Forum: Hybridization
Topic: Hybridization
Replies: 5
Views: 320

Re: Hybridization

Hybridized orbitals are lower in energy compared to their separated, unhybridized counterparts. This results in more stable compounds
by Michele Shi 1K
Sun Nov 19, 2017 9:01 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.25 (Polarity)
Replies: 4
Views: 283

Re: 4.25 (Polarity)

To my knowledge, that is correct. You can also tell if a compound is polar or nonpolar based on the symmetry of the compound. If all the "outside" atoms are the same element, then it is non polar because the elecrtrons will be distributed equally. Sometimes a compound can have polar bonds ...
by Michele Shi 1K
Sun Nov 19, 2017 8:52 pm
Forum: Hybridization
Topic: 4.33 (c)
Replies: 2
Views: 231

Re: 4.33 (c)

You should look at the 4 areas of electron density which corresponds to the sp^3 hybridization
by Michele Shi 1K
Mon Nov 13, 2017 9:42 am
Forum: Determining Molecular Shape (VSEPR)
Topic: AXE [ENDORSED]
Replies: 2
Views: 157

AXE [ENDORSED]

Is it more helpful to remember the AXE format when determining shape? Or is it better to visualize? Also how many different shapes are there that we responsible for knowing?
by Michele Shi 1K
Mon Nov 13, 2017 9:39 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Organic vs inorganic molecules
Replies: 3
Views: 235

Organic vs inorganic molecules

Can someone please explain the difference between organic and inorganic molecules? How does shape differ between them? THanks!
by Michele Shi 1K
Sat Nov 04, 2017 10:49 am
Forum: Lewis Acids & Bases
Topic: How to tell when a molecule is an acid or base
Replies: 2
Views: 450

How to tell when a molecule is an acid or base

How can I distinguish a molecule as an acid or base? I know that acids accept electrons and bases donate electrons. But by just looking at the molecular formula (BF3 for example), how do I know that Boron will not have an octet because it will accept another lone pair? Thank!
by Michele Shi 1K
Sat Nov 04, 2017 10:46 am
Forum: Octet Exceptions
Topic: Boron Trifluoride lewis structure [ENDORSED]
Replies: 1
Views: 263

Boron Trifluoride lewis structure [ENDORSED]

Hi! In class, we drew out the boron trifluoride lewis structure and the end result had 3 single bonds connecting B to each F atom. This did not give Boron an octet. Professor Lavelle explained how the Boron can accept another lone pair to make an octet. How am i supposed to know when to have some le...
by Michele Shi 1K
Fri Oct 27, 2017 4:14 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbital Angular Momentum Quantum Number
Replies: 2
Views: 217

Re: Orbital Angular Momentum Quantum Number

The angular momentum quantum number l refers to the shape that the orbits can be. It can take the values ranging from 0,1,... n-1. When l=0, it is referring to the s orbital, l=1 refers to the p orbital, l=2 refers to the d orbital and l=3 refers to the f orbitals.
by Michele Shi 1K
Fri Oct 27, 2017 4:01 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Putting s orbital or p orbital first [ENDORSED]
Replies: 4
Views: 395

Putting s orbital or p orbital first [ENDORSED]

Hello! In my discussion, we were writing the electron configuration for the element Titanium Ti. The answer I got was [Ar](3d^2)(4s^2). I am confused when i should put the s orbital first or when i should put the d orbital first. I know the last term should be the highest energy level, but in my dis...
by Michele Shi 1K
Fri Oct 20, 2017 1:51 am
Forum: Photoelectric Effect
Topic: Problem in post assessment
Replies: 2
Views: 177

Problem in post assessment

Hello! In a problem in the post assessment, it gave me the kinetic energy of an electron but then asked to find the incident energy. How do I go about if I dont know the threshold?
by Michele Shi 1K
Fri Oct 20, 2017 1:49 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Uncertainty
Replies: 1
Views: 170

Heisenberg Uncertainty

I saw an example in Khan academy for this uncertainty equation. The example said there was a 10% uncertainty for the momentum and then they just multiplied it by .1 but I'm wondering why they didnt multiply by .9. Thanks
by Michele Shi 1K
Fri Oct 13, 2017 9:15 am
Forum: Properties of Light
Topic: Heisenberg uncertainty Principle
Replies: 1
Views: 163

Heisenberg uncertainty Principle

Can someone explain the Heisenberg uncertainty principle more in detail? I dont understand the equation either (why the h bar???). Thank you!!!
by Michele Shi 1K
Fri Oct 13, 2017 9:01 am
Forum: Properties of Light
Topic: Difference Between Photon and Electron
Replies: 5
Views: 883

Re: Difference Between Photon and Electron

Photons and electrons can be related especially during the Photoelectric effect. The photon has the energy going in and must have enough energy (threshold energy) of the metal in order to have an electron be released.
by Michele Shi 1K
Thu Oct 05, 2017 1:59 pm
Forum: Empirical & Molecular Formulas
Topic: Mass Percent Composition
Replies: 4
Views: 310

Re: Mass Percent Composition

I have the same question. For problem F21, the solution manual didn't find the mass percentage composition for each element. They just went directly from the given grams of each element to moles. I thought it would change the number of moles if you didn't assume the 100g sample.
by Michele Shi 1K
Thu Oct 05, 2017 1:56 pm
Forum: Empirical & Molecular Formulas
Topic: Fundamentals F21
Replies: 3
Views: 284

Fundamentals F21

A sample of the compound didemnin-A of mass 1.78g was analyzed and found to have the following composition: 1.1mg C, 0.148 mg H, 0.159 mg N, and 0.363 mg O. the molar mass of didemnin-A was found to be 942 g/mol. What is the molecular formula of didemnin-A? My initial approach was to convert each el...

Go to advanced search