Search found 51 matches

by Serena Siddiq 3D
Mon Dec 09, 2019 3:18 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pka and ka
Replies: 4
Views: 78

Re: pka and ka

Since kA represents the amount of H+ concentration at equilibrium for weak acids, it will be high if the acid has a high H+ and vice versa. The pkA is inversely related to this as it is the -log of this number (hence p in front) and would be lower if the weak acid was on the stronger side and vice v...
by Serena Siddiq 3D
Mon Dec 09, 2019 3:10 am
Forum: Bronsted Acids & Bases
Topic: amphoteric
Replies: 7
Views: 107

Re: amphoteric

To add onto the last answer, something that is amphiprotic (can give off an H+ or accept it) will be amphoteric (in reactions could act as acid and a base) but it wont be true the other way around.
by Serena Siddiq 3D
Mon Dec 09, 2019 3:06 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: H bonding
Replies: 4
Views: 77

Re: H bonding

Diana A 1G wrote:Why are hydrogen atoms bound to Carbon atoms not considered in determining hydrogen binding sites?

They are not considered because hydrogen bonding is a special form of dipole-dipole that only attracts to another molecule’s N, O, or F atoms. C is not included in here, therefore it does not occur!
by Serena Siddiq 3D
Sat Dec 07, 2019 12:39 am
Forum: Bronsted Acids & Bases
Topic: J.7
Replies: 8
Views: 86

Re: J.7

Since this is a neutralization problem, your products are water and whatever they give you; now, you need to figure out what its reactants are from those. So, for A, you see that KBr and H2O are the products. So, the reactants must be KOH (base) and HBr (acid). This combination of H+ ions and OH- i...
by Serena Siddiq 3D
Sat Dec 07, 2019 12:10 am
Forum: Administrative Questions and Class Announcements
Topic: Final Exam Place
Replies: 3
Views: 71

Re: Final Exam Place

There is a link on his website you can click on that says Final Location or something and it will tell you what your room is based on your lecture and last name :)
by Serena Siddiq 3D
Wed Nov 27, 2019 12:50 am
Forum: Naming
Topic: Naming Coordination Compound
Replies: 5
Views: 45

Re: Naming Coordination Compound

It will go after the metal's charge since it is out of the sphere. For example, if it looked like [Fe(CN)6]4- Cl, then it would be hexacyanoferrate (II) chloride ion. Hope that helps!
by Serena Siddiq 3D
Wed Nov 27, 2019 12:47 am
Forum: Naming
Topic: 9C.1
Replies: 6
Views: 75

Re: 9C.1

To answer each of these, you should lay out what how much of everything you have so you can figure out the charge of the metal. Since there are 6 CN- and the overall charge is 4-, that means the charge of Fe is 2+. So you now can write out the name for it by beginning with each ligand, in alphabetic...
by Serena Siddiq 3D
Wed Nov 27, 2019 12:31 am
Forum: Bronsted Acids & Bases
Topic: J.7
Replies: 8
Views: 86

Re: J.7

Since this is a neutralization problem, your products are water and whatever they give you; now, you need to figure out what its reactants are from those. So, for A, you see that KBr and H2O are the products. So, the reactants must be KOH (base) and HBr (acid). This combination of H+ ions and OH- io...
by Serena Siddiq 3D
Wed Nov 27, 2019 12:21 am
Forum: Identifying Acidic & Basic Salts
Topic: J.9B
Replies: 1
Views: 58

Re: J.9B

I believe they are the same product, just in a different notation. H3PO4 did donate its proton to NH3. Don't forget that each compund has a charge on it, so as long as you make sure that they cancel out when put together like the product is given in the solution manual, the product given is correct ...
by Serena Siddiq 3D
Wed Nov 27, 2019 12:08 am
Forum: Hybridization
Topic: PCl6
Replies: 3
Views: 51

Re: PCl6

Since P is bonded to 6 other atoms, its shape is an octahedral and has 6 regions of electron density. Therefore, its hybridization must be sp3d2, which accounts for all 6 of those regions. Hope that helps!
by Serena Siddiq 3D
Sun Nov 24, 2019 5:33 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: What is a coordinate number?
Replies: 3
Views: 25

Re: What is a coordinate number?

It can also be looked at as the number of electron donor atoms (ligands) connected to the central metal cation.
by Serena Siddiq 3D
Sun Nov 24, 2019 5:27 pm
Forum: Hybridization
Topic: Bond angles
Replies: 2
Views: 39

Re: Bond angles

I think just removing any extra repulsion added to the molecule like electron pairs since they push down on the other bonds and lessen the angles. For example, if you take the electron pairs off of a bent molecule, it goes from having a slightly less than 109.5 degree bond angle to 180 as a liner mo...
by Serena Siddiq 3D
Sun Nov 24, 2019 5:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Dipole Moment?
Replies: 4
Views: 42

Re: Dipole Moment?

When people talk about symmetry, it just means that if you were to fold the molecule evenly, it would be able to be equal on all sides, like O2 or CH4. In this case, molecules like these would be nonpolar because if they are symmetrical, they have equal pulls/charge distributions. On the other hand,...
by Serena Siddiq 3D
Sun Nov 24, 2019 5:05 pm
Forum: Lewis Acids & Bases
Topic: lewis vs. bronsted
Replies: 10
Views: 84

Re: lewis vs. bronsted

This is incorrect, Bronsted Acids donate PROTONS not electrons.
Johnathan Smith 1D wrote:Bronsted acids donate electrons and Lewis acids accept electrons
by Serena Siddiq 3D
Thu Nov 21, 2019 11:38 pm
Forum: Hybridization
Topic: HW 2.57
Replies: 2
Views: 31

Re: HW 2.57

The hybridization should be for the second carbon, not the nitrogen. So, the hybridization is sp since there are 2 regions of electron density around the carbon.
by Serena Siddiq 3D
Sun Nov 17, 2019 9:40 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR model for ions
Replies: 2
Views: 20

Re: VSEPR model for ions

I believe we treat them the same, just consider the extra electrons or loss of them from the charge when making the Lewis structure so it is accurate to define using VSEPR.
by Serena Siddiq 3D
Sun Nov 17, 2019 9:25 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E. 27
Replies: 3
Views: 28

Re: 2E. 27

Nonpolar: You are looking to see if their dipole moments cancel each other out by being across from each other/equal or if it just has no dipoles at all. The charge is distributed symmetrically, if any.

Polar: Dipoles that do not cancel by being across each other/not symmetrically.
by Serena Siddiq 3D
Sun Nov 17, 2019 9:10 pm
Forum: Hybridization
Topic: d orbital
Replies: 3
Views: 32

Re: d orbital

The d orbital allows those elements that are period 3 and higher to have more room to fit electrons and therefore, satisfy the octet rule. This lets the central atom have extra lone pairs on them and therefore, the Lewis structure will have high repulsion to the bonded electrons form the higher dens...
by Serena Siddiq 3D
Sun Nov 17, 2019 9:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pairs
Replies: 10
Views: 63

Re: Lone Pairs

Lone pairs have more electron density and are delocalized, so when they move around the entire molecule at any given moment they are able to have a stronger repulsion power than bonded pairs.
by Serena Siddiq 3D
Sun Nov 17, 2019 8:57 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar and Nonpolar
Replies: 6
Views: 160

Re: Polar and Nonpolar

Visualizing it is the best way, so draw out the Lewis Structures as accurately as possible (based on valence electron count and formal charge like usual), you will see if dipole moments occur that are not symmetrical. What I mean is, if there is a tetrahedral like CCl4, there are dipole moments on e...
by Serena Siddiq 3D
Sun Nov 10, 2019 11:58 pm
Forum: Bond Lengths & Energies
Topic: London Forces
Replies: 6
Views: 56

Re: London Forces

Yes, all molecules have London Dispersion forces since all of them have electrons
by Serena Siddiq 3D
Sun Nov 10, 2019 11:56 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Anions
Replies: 7
Views: 45

Re: Anions

No, because the first two rows of the periodic table are metal cations, and therefore have polarizing power. So, not all metals are good candidates for polarizability!
by Serena Siddiq 3D
Sun Nov 10, 2019 11:53 pm
Forum: Bond Lengths & Energies
Topic: Size
Replies: 9
Views: 67

Re: Size

The larger the radius of the atoms, the farther each of their centers are apart, and therefore, they have a longer and weaker bond length than smaller radius atoms. The smaller the radius of the atoms, the closer their centers are, and therefore, they have a stronger and shorter bond length than lar...
by Serena Siddiq 3D
Sun Nov 10, 2019 11:51 pm
Forum: Electronegativity
Topic: Noble Gases
Replies: 19
Views: 380

Re: Noble Gases

Not usually, since they are perfect octets (have all orbitals filled depending on where it sits on the periodic table), they do not want to attract anymore electrons, nor lose them. They want to stay as stable as they are, so technically their electronegativity levels are very small to none and ther...
by Serena Siddiq 3D
Sun Nov 10, 2019 11:47 pm
Forum: Quantum Numbers and The H-Atom
Topic: The spin of a quantum number
Replies: 6
Views: 89

Re: The spin of a quantum number

When you are asked to figure out the quantum numbers, you won't know which way it is. It doesn't matter though, either is correct unless it says one is spinning up or down (correspond the + or - to its direction). Hope that helps!
by Serena Siddiq 3D
Sun Nov 03, 2019 9:57 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 3
Views: 29

Re: Formal Charge

You should calculate it whether it is in the directions or not to make sure the lewis structure you made is the most stable/accurate based off of the formal charges; it is considered a step when creating the structures.
by Serena Siddiq 3D
Sun Nov 03, 2019 9:47 pm
Forum: Formal Charge and Oxidation Numbers
Topic: formal charge
Replies: 4
Views: 41

Re: formal charge

Formal charge allows us to find the most stable Lewis structure of a compound because we can draw many valid structures that match the total number of valence electrons, but we want the most STABLE. The most stable structure will have majority of its formal charges equal to 0. When it is an ionic co...
by Serena Siddiq 3D
Thu Oct 31, 2019 1:41 pm
Forum: Lewis Structures
Topic: octet exceptions
Replies: 5
Views: 42

Re: octet exceptions

You know if it is an octet exception if you are drawing the Lewis structure and you are not matching up with the amount of electrons it should have because the bonds you make lower the amount of lone pairs to be counted on the separate atom. If this happens, as long as it is the central atom is in p...
by Serena Siddiq 3D
Thu Oct 31, 2019 1:36 pm
Forum: Ionic & Covalent Bonds
Topic: Lewis structure
Replies: 3
Views: 37

Re: Lewis structure

The easiest way to figure out which one goes in the middle is the one that has the LOWEST ionization energy, so which ever atom is higher up and more to the left than the other. It is also easy if there is a molecule like PBr5 to know which one will be in the middle, which is P because there is only...
by Serena Siddiq 3D
Thu Oct 31, 2019 1:33 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 5
Views: 42

Re: Formal Charge

You use the formal charge equation when you want to know if the Lewis structure you drew is the most accurate it can be, with the most formal charges of 0 as possible, meaning all valence electrons for each atom are accounted for as much as possible.
by Serena Siddiq 3D
Sun Oct 27, 2019 11:56 pm
Forum: Lewis Structures
Topic: lewis structures
Replies: 5
Views: 52

Re: lewis structures

The one that goes in the center is whichever one has the lower ionization energy! I would also make sure you are making the Lewis structure symmetrical, like CO2 would have C in the middle and the two Os on each side. Hope this helps!
by Serena Siddiq 3D
Sun Oct 27, 2019 11:55 pm
Forum: Student Social/Study Group
Topic: Midterm
Replies: 17
Views: 212

Re: Midterm

Yes the midterm will have everything we have learned thus far: Fundamentals, Quantum, Chemical Bonds, and whatever we learn until the midterm :) From the beginning.
by Serena Siddiq 3D
Sun Oct 27, 2019 11:52 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configurations
Replies: 3
Views: 44

Re: Electron Configurations

We won't be asked to do that, I think we just need to know how to write out the configurations based on the periodic table, like 1s^2, 2s^2,...etc :)
by Serena Siddiq 3D
Sun Oct 27, 2019 11:49 pm
Forum: Octet Exceptions
Topic: Octet Rule Exceptions
Replies: 2
Views: 28

Re: Octet Rule Exceptions

All it is saying is that because those elements are farther down the periodic table than period 3, they can accommodate for more electrons if need be since they have more room in their shells (sometimes they do not have to) depending on the compound you are drawing a Lewis structure for. Hope that h...
by Serena Siddiq 3D
Sun Oct 27, 2019 11:46 pm
Forum: Ionic & Covalent Bonds
Topic: Ground State
Replies: 11
Views: 98

Re: Ground State

To add, a ground state electron configuration is simply just asking you to find it based on its placement on the periodic table. If it were an excited state, the electron configuration would have the orbitals filled up with arrows all over the place, instead of following the form we learned of a gro...
by Serena Siddiq 3D
Sun Oct 20, 2019 9:37 pm
Forum: Einstein Equation
Topic: Alternative unit for J
Replies: 4
Views: 50

Re: Alternative unit for J

1 J is the same as 1 kg•m^2•s^-2 and is on the conversion sheets we will receive for tests!
by Serena Siddiq 3D
Sun Oct 20, 2019 9:35 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: delta p
Replies: 3
Views: 31

Re: delta p

delta p is the uncertainty of the electron or object’s momentum, which is equal to the mass times the uncertainty in velocity of the electron or object.

Δp = mass x Δv
^delta stands for “uncertainty of” in this equation
by Serena Siddiq 3D
Sun Oct 20, 2019 9:30 pm
Forum: Naming
Topic: Naming Compounds (general question)
Replies: 9
Views: 115

Re: Naming Compounds (general question)

Polyatomic ions are expected for us to be familiar with, so I would say study those! I know the prefixes/suffixes all correspond to the different formations like nitrOUS acid (HNO2) vs nitrIC acid (HNO3) and should be the same across the board for other compounds, maybe that will make it easier to l...
by Serena Siddiq 3D
Sun Oct 20, 2019 9:23 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Noble Gases in Electron Configurations
Replies: 6
Views: 31

Re: Noble Gases in Electron Configurations

We are able to use the noble gases as a shortcut when writing out the configurations because they are perfect octets, meaning all of their orbitals have paired electrons. Since this is true, you can start at whatever the noble gas right before the element you are writing the configuration for on the...
by Serena Siddiq 3D
Sun Oct 20, 2019 9:17 pm
Forum: Quantum Numbers and The H-Atom
Topic: M Value
Replies: 3
Views: 38

Re: M Value

The m sub l value is the orientation of the orbital in a sub-level and can be either -l, l-1, or +l; so it can be a positive, negative, or 0 integer. You can see what the possibilities are based on the l values! Hope this helps
by Serena Siddiq 3D
Mon Oct 14, 2019 12:35 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: 1A.11 What is common to each series that groups their spectral lines together?
Replies: 2
Views: 27

1A.11 What is common to each series that groups their spectral lines together?

The Balmer series and Lyman series and their importance are hard for me to understand. Can someone explain to me what makes them group together? Why are these series important in this section?

Thank you in advance!
by Serena Siddiq 3D
Sun Oct 13, 2019 10:58 pm
Forum: *Black Body Radiation
Topic: Black Body
Replies: 6
Views: 142

Re: Black Body

What would be an example of a black body? Is this something people produce out there? I think it sounds like a really interesting topic, but it doesn't sound like it is feasible to be made in real life. Examples of black bodies are the Sun and appliances that get really hot, like a stove since ther...
by Serena Siddiq 3D
Sun Oct 13, 2019 10:50 pm
Forum: Properties of Light
Topic: De Broglie equation
Replies: 4
Views: 61

Re: De Broglie equation

Kennedi3K wrote:Do you guys think that would be asked explicitly in the problem so we would know when to use it ?

Yes, it will ask for the "De Broglie wavelength" specifically. All the examples done in lecture have been that way.
by Serena Siddiq 3D
Sun Oct 13, 2019 10:45 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Bohr Frequency Condition??
Replies: 3
Views: 41

Bohr Frequency Condition??

Just for clarification, it is only used regarding a DROP of an electron from one energy level to another (releasing a photon), not when it goes from a lower to higher energy level (absorbing a photon), right? Will we ever need calculate the latter?
by Serena Siddiq 3D
Sun Oct 13, 2019 10:27 pm
Forum: Properties of Electrons
Topic: Energy levels
Replies: 4
Views: 63

Re: Energy levels

Every atom has an infinite amount of energy levels
by Serena Siddiq 3D
Sun Oct 13, 2019 10:18 pm
Forum: Properties of Electrons
Topic: Photon
Replies: 5
Views: 31

Re: Photon

A photon is a particle that functions as a packet of energy during electromagnetic radiation (including visible light and other rays on the electromagnetic spectrum). Its energy is related to the frequency of the radiation and can be found using the equation E=hv.
by Serena Siddiq 3D
Fri Oct 04, 2019 6:06 pm
Forum: Limiting Reactant Calculations
Topic: Percent Yield
Replies: 6
Views: 63

Re: Percent Yield

If the actual yield is given in grams do we change it to moles or do we change the theoretical yield to grams if its in moles? The formula for percent yield uses both actual and theoretical yields in grams, so I would suggest always making sure both are in grams! Unless the problem asks for the act...
by Serena Siddiq 3D
Fri Oct 04, 2019 5:53 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Use of Avogadro's number
Replies: 3
Views: 41

Re: Use of Avogadro's number

It is the number of units in one mole of any substance. So, 6.022140857 × 10^23 units of "something", which can include electrons, atoms, ions, or molecules, depending on the problem. It is used a lot when trying to find the mass of those objects. Hope this helps!
by Serena Siddiq 3D
Fri Oct 04, 2019 5:49 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Molar mass
Replies: 3
Views: 43

Re: Molar mass

Since it is asking for grams of a single molecule, you have to use Avagadro's number because it represents "things" in one mole, which includes molecules. So you would divide the 1 water molecule by 6.02x10^23 molecules of a mole, then multiply by the molar mass of water, which is 18.02 g/...
by Serena Siddiq 3D
Fri Oct 04, 2019 5:37 pm
Forum: Limiting Reactant Calculations
Topic: Homework M.15
Replies: 2
Views: 48

Re: Homework M.15

The first conversion would look like this: 255. g Al x 1 mol x 2 mol AlCl3 x 133.341 g AlCl3 ------------------------------------------------ = 26.982g Al x 2 mol Al x 1 mol AlCl3 You start with what grams are given, then convert to moles using the molar mass from the periodic table, then use the ba...
by Serena Siddiq 3D
Fri Oct 04, 2019 5:25 pm
Forum: Properties of Light
Topic: c = fλ
Replies: 9
Views: 93

Re: c = fλ

Savannah Mance 3B wrote:So, even if the f or λ changes, it is still always equal to 3.00 x 10^8 m.s. ^-1/?


Yes, I know it sounds wrong since one side of the equation is changing, the other side should as well. But, the speed of light is constant, so it would not be affected by the changes in frequency and wavelength.

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