Search found 39 matches

by Amina Durrani 3G
Sun Nov 17, 2019 10:35 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Instantaneous Dipole versus Induced Dipole
Replies: 4
Views: 12

Instantaneous Dipole versus Induced Dipole

What’s the difference between instantaneous dipole and induced dipole????
by Amina Durrani 3G
Sun Nov 17, 2019 12:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar Molecules and Symmetry
Replies: 3
Views: 14

Polar Molecules and Symmetry

Can you assume a molecule is polar if it's non symmetrical?
by Amina Durrani 3G
Sun Nov 17, 2019 12:31 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.25
Replies: 2
Views: 15

2E.25

Why is part d polar? Do lone pairs cause dipole moments?
by Amina Durrani 3G
Sat Nov 16, 2019 12:58 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Long pairs
Replies: 3
Views: 14

Long pairs

Why do molecules with lone pairs will have angles slightly less than what their shape would be without lone pairs?
by Amina Durrani 3G
Sat Nov 16, 2019 12:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sulfite Ion example in class
Replies: 6
Views: 15

Sulfite Ion example in class

In my notes I wrote that the bond angles of O-S-O are 106 degrees not 109.5 degrees, but why is this?
by Amina Durrani 3G
Sat Nov 16, 2019 12:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hydrogen Bonding
Replies: 2
Views: 9

Hydrogen Bonding

Is Hydrogen Bonding only present in molecules with N,O,F atoms or are there other atoms that also hydrogen bond?
by Amina Durrani 3G
Sat Nov 16, 2019 12:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Distortion and Polarizability
Replies: 2
Views: 13

Distortion and Polarizability

How are electron distortion and polarizability of that electron related? Is distortion and changing molar mass the same?
by Amina Durrani 3G
Sat Nov 16, 2019 12:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Interaction Potential Energy
Replies: 3
Views: 19

Interaction Potential Energy

Can someone explain what the equation for interaction potential energy is and it’s significance?
by Amina Durrani 3G
Sat Nov 16, 2019 12:43 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: 5
Views: 21

Re: Test 2

Basically all intermolecular interactions, so post midterm until next Monday’s lecture (we have to know pi and sigma bonds from that lecture).
by Amina Durrani 3G
Sat Nov 09, 2019 1:11 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: instantaneous dipoles
Replies: 3
Views: 15

Re: instantaneous dipoles

I think surface area since increased surface area means increased noncovalent interactions between molecules which means that it will take more energy/heat to break them apart thus increasing boiling point.
by Amina Durrani 3G
Sat Nov 09, 2019 1:07 pm
Forum: Lewis Structures
Topic: Lewis Structures
Replies: 4
Views: 20

Re: Lewis Structures

The more electronegative atom should have a negative charge if the other atom’s charge is 0, but it should have a 0 charge if the other atom’s charge is positive.
by Amina Durrani 3G
Sat Nov 09, 2019 1:04 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: Dipole-Dipole vs London
Replies: 4
Views: 20

Dipole-Dipole vs London

What’s the difference between Dipole-Dipole and London Forces and what’s an example of each?
by Amina Durrani 3G
Sat Nov 09, 2019 1:02 pm
Forum: Resonance Structures
Topic: 2.7 - How to determine main structure if formal charges are equal?
Replies: 2
Views: 16

Re: 2.7 - How to determine main structure if formal charges are equal?

The lowest energy structure would have the most electronegative N in the middle (-1 FC) and the two other N’s (+1 FC) on either side.
by Amina Durrani 3G
Sat Nov 02, 2019 5:11 pm
Forum: Lewis Structures
Topic: Expanded Valence Shells
Replies: 3
Views: 14

Expanded Valence Shells

How exactly do expanded valence shells work, since the octet rule says that atoms share electrons until a noble gas configuration is reached?
by Amina Durrani 3G
Sat Nov 02, 2019 5:05 pm
Forum: Sigma & Pi Bonds
Topic: Double bond
Replies: 15
Views: 94

Re: Double bond

Two things to pay attention to are formal charge and octets. Most elements want to have a full shell of valence electrons, so try to make sure that they all have 8 electrons around them. Next is to pay attention to the formal charge. If by forming a double bond, the formal charge is closer to 0, th...
by Amina Durrani 3G
Sat Nov 02, 2019 5:01 pm
Forum: Lewis Structures
Topic: Ion formation vs molecule
Replies: 2
Views: 21

Ion formation vs molecule

How do you know if the lowest energy can be achieved by ion formation or if it can be achieved by sharing electrons? Like how do you know when you should write Na+Cl- or just NaCl?
by Amina Durrani 3G
Sat Nov 02, 2019 4:54 pm
Forum: Lewis Structures
Topic: Resonance Hybrids
Replies: 3
Views: 16

Resonance Hybrids

What does resonance hybrids mean? And what’s an example of resonance versus resonance hybrid?
by Amina Durrani 3G
Sat Nov 02, 2019 4:52 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Copper and Chromium Exception
Replies: 2
Views: 12

Copper and Chromium Exception

Can someone explain what the Copper and Chromium exceptions are for electron configuration?
by Amina Durrani 3G
Sat Oct 26, 2019 3:45 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Bonds
Replies: 5
Views: 33

Covalent Bonds

Why don't non metals form cations?
by Amina Durrani 3G
Sat Oct 26, 2019 2:59 pm
Forum: Ionic & Covalent Bonds
Topic: Midterm 2
Replies: 4
Views: 33

Re: Midterm 2

Jessica Li 1F wrote:I think there's only one midterm (on Nov. 6), and that one will be cumulative all the way from Test 1.


So is the review of chemical principles (all the Test 1 stuff) going to be on the midterm? Or everything after that?
by Amina Durrani 3G
Sat Oct 26, 2019 2:23 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: #1E17 help
Replies: 1
Views: 14

#1E17 help

For part b of this problem, the electron configuration for Mn is [Ar] 4s^2 3d^5 right? The question is asking from which orbital will an electron be removed to form a +1 ion, and the correct answer is from the 4s orbital but can someone explain why its from this orbital and not 3d^5?
by Amina Durrani 3G
Sun Oct 20, 2019 6:12 pm
Forum: Quantum Numbers and The H-Atom
Topic: Magnetic Quantum Number ml
Replies: 5
Views: 12

Re: Magnetic Quantum Number ml

So like what would be an example?
by Amina Durrani 3G
Sun Oct 20, 2019 6:11 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Tips for Subshells
Replies: 4
Views: 19

Re: Tips for Subshells

Wait, why can you only use a noble gas again? I’m little confused.
by Amina Durrani 3G
Sun Oct 20, 2019 6:09 pm
Forum: Quantum Numbers and The H-Atom
Topic: Magnetic Quantum Number ml
Replies: 5
Views: 12

Magnetic Quantum Number ml

What does ml describe? I know that n’s the shell, and l is the sub shell that describes shape, but what does ml describe then?
by Amina Durrani 3G
Sun Oct 20, 2019 6:03 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Quantum Numbers
Replies: 3
Views: 12

Quantum Numbers

Is the third quantum number m or ml ? I remember learning the other two were n and l but I couldn’t tell from the slides if the third was m or ml
by Amina Durrani 3G
Sun Oct 20, 2019 5:56 pm
Forum: *Shrodinger Equation
Topic: Schrodinger’s Wave Function
Replies: 3
Views: 29

Schrodinger’s Wave Function

What does it mean by the square of the wave function represents the probability of finding an electron?
by Amina Durrani 3G
Sun Oct 20, 2019 5:53 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Uncertainty Principle
Replies: 2
Views: 21

Heisenberg Uncertainty Principle

I know that the Heisenberg Uncertainty Principle tells us that there is a physical limit to the minimum size that atoms can exist, but is there a maximum size too? If so how could we calculate that?
by Amina Durrani 3G
Sun Oct 13, 2019 12:35 pm
Forum: Properties of Light
Topic: Problem 1A.9
Replies: 2
Views: 18

Re: Problem 1A.9

To calculate the energy of a photon use E=hv and to match the kind of radiation to the appropriate event compare the wavelength to the chart we viewed in class which gave the type of radiation and it’s corresponding wavelength.
by Amina Durrani 3G
Sun Oct 13, 2019 12:22 pm
Forum: Photoelectric Effect
Topic: Intensity, frequency, and wavelength
Replies: 5
Views: 37

Re: Intensity, frequency, and wavelength

From what I understood in lecture, increasing light intensity increases the number of photons which results in more ejected electrons (if the energy per photon is greater or equal to the energy needed to remove an electron).
by Amina Durrani 3G
Sun Oct 13, 2019 12:18 pm
Forum: DeBroglie Equation
Topic: De Broglie Equation Clarification
Replies: 4
Views: 35

De Broglie Equation Clarification

I know that the De Broglie Equation states that any moving particle with momentum, p, has wavelike properties with wavelength, lambda, but what exactly are the wavelike properties?
by Amina Durrani 3G
Sun Oct 13, 2019 12:13 pm
Forum: Properties of Electrons
Topic: Diffraction Patterns
Replies: 3
Views: 23

Diffraction Patterns

In lecture we talked about how light (waves) in general show diffraction patterns and then we used the example of and x-ray passing through a crystal, can someone clarify how this example shows diffraction patterns?
by Amina Durrani 3G
Sun Oct 13, 2019 12:04 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: En=-hR/n^2
Replies: 3
Views: 21

Re: En=-hR/n^2

Yes, because Hydrogen only has one electron, but if there are multiple electrons then the electrons repel each other and you can’t calculate the ground-state energy of that atom if the electrons are already repelling each other.
by Amina Durrani 3G
Sun Oct 13, 2019 12:00 pm
Forum: Properties of Electrons
Topic: wave properties of electrons
Replies: 5
Views: 19

Re: wave properties of electrons

In constructive interference the crests or troughs of the waves interfere with the other meaning that their amplitudes are added to get the total amplitude of the wave, however in destructive interference the crests or troughs of the waves interfere with each other meaning that the amplitudes are su...
by Amina Durrani 3G
Fri Oct 04, 2019 7:20 pm
Forum: Empirical & Molecular Formulas
Topic: Chemical Formulas
Replies: 3
Views: 26

Re: Chemical Formulas

I remember learning in HS that Carbon goes first, then Hydrogen, and then all other elements but in alphabetical order. Hope this helps (:
by Amina Durrani 3G
Fri Oct 04, 2019 7:18 pm
Forum: Properties of Light
Topic: Amplitude
Replies: 6
Views: 44

Re: Amplitude

Amplitude is a measure of length or distance similar to wavelength, but has no relation to frequency! I think it’s just a quantity that can be measured or solved for
by Amina Durrani 3G
Fri Oct 04, 2019 7:14 pm
Forum: Significant Figures
Topic: Sig figs for percent yield
Replies: 2
Views: 34

Re: Sig figs for percent yield

Yes. Your answer should have the same number of sig figs as the value given in the question with the smallest amount of sig figs!
by Amina Durrani 3G
Fri Oct 04, 2019 7:12 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7606
Views: 1018060

Re: Post All Chemistry Jokes Here

Two chemists walk into a bar.
One says, “I’ll have an ‎H2O.” The other says, “I’ll have an ‎H2O, too.” The second chemist dies.

He He He (Helium Helium Helium)

Go to advanced search