Search found 37 matches

by Rodrigo3H
Sat Nov 16, 2019 2:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sulfite Ion example in class
Replies: 6
Views: 15

Re: Sulfite Ion example in class

Remember that in a sulfite ion there is a lone pair of electrons attached to the sulfur atom. Because lone pairs are more repulsive than atoms, they slightly change the bond angles between the atoms to slightly less than 109.5 degrees. We don't have know the exact bond angles, we just say that they ...
by Rodrigo3H
Sat Nov 16, 2019 2:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hydrogen Bonding
Replies: 2
Views: 9

Re: Hydrogen Bonding

Remember that hydrogen bonds do not occur within a single molecule rather they are present when multiple molecules with hydrogen atoms bonded to highly electronegative atoms (N, O, F) are next to each other.
by Rodrigo3H
Sat Nov 16, 2019 2:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Determining if a molecule is polar or non polar
Replies: 9
Views: 36

Re: Determining if a molecule is polar or non polar

I don't think it will be necessary to know specific electronegativity numbers, but there are some cases in which you can use the the trends of electronegativity to determine if the molecule has a net dipole moment. If it does, it will be polar. If not then it will be non polar.
by Rodrigo3H
Sat Nov 16, 2019 2:17 pm
Forum: Administrative Questions and Class Announcements
Topic: Class Grading
Replies: 3
Views: 31

Re: Class Grading

I think it might depend on how the class does overall. He might look at the average, and if it's bad he might scale grades a little differently.
by Rodrigo3H
Sat Nov 09, 2019 12:23 pm
Forum: Trends in The Periodic Table
Topic: Effective Nuclear Charge
Replies: 5
Views: 36

Re: Effective Nuclear Charge

Effective nuclear charge is the net positive charge that valence electrons experience in a multi-electron atom. Generally as the number of electrons increases in an atom, the effective nuclear charge experienced by valence electrons decreases.
by Rodrigo3H
Sat Nov 09, 2019 12:14 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

instantaneous dipoles

what is more important in determining the relative boiling/melting point of a molecule: surface area (shape) of the molecule or the number of electrons?
by Rodrigo3H
Sat Nov 09, 2019 12:04 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: hydrogen vs london
Replies: 2
Views: 20

Re: hydrogen vs london

As far as I know, hydrogen bonds are always stronger than dipole-dipole and London dispersion forces.
by Rodrigo3H
Sat Nov 09, 2019 11:58 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: Hydrogen bonding
Replies: 4
Views: 16

Re: Hydrogen bonding

Also only highly electronegative atoms can form hydrogen bonds with hydrogen. These atoms are Nitrogen, Oxygen, and Flourine. I don't think CO can form a hydrogen bond with H2O because if you draw out the lewis structure for CO you will see that Carbon has a partial negative charge and oxygen has a ...
by Rodrigo3H
Sat Nov 09, 2019 11:50 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: Hydrogen bonding
Replies: 4
Views: 16

Re: Hydrogen bonding

For a hydrogen bond to occur, the hydrogen atom has to be bonded to two highly electronegative atoms. So, if we are looking at use one water molecule we cannot say that the bonds between the O and H are hydrogen bonds because there is only one highly electronegative atom. If we had 2 water molecules...
by Rodrigo3H
Sat Nov 02, 2019 11:10 pm
Forum: Octet Exceptions
Topic: Boron and Aluminum
Replies: 1
Views: 18

Boron and Aluminum

Can someone explain why Boron and Aluminum (as examples) can be stable without a complete octet?
by Rodrigo3H
Sat Nov 02, 2019 10:53 pm
Forum: Electronegativity
Topic: What is isoelectronic?
Replies: 13
Views: 49

Re: What is isoelectronic?

Isoelectronic just refers to atoms/ions with the same number of electrons. Ex) Na+, F-, Ne — they all have the same # of electrons!
by Rodrigo3H
Sat Nov 02, 2019 10:45 pm
Forum: Lewis Structures
Topic: Dino Nugs 12b
Replies: 5
Views: 32

Re: Dino Nugs 12b

Because oxygen is more electronegative than chlorine, it is “happier” with a -1 charge than chlorine would be.
by Rodrigo3H
Sat Nov 02, 2019 10:38 pm
Forum: Ionic & Covalent Bonds
Topic: Midterm
Replies: 28
Views: 149

Re: Midterm

Everything we have learned so far except intermolecular forces I believe!
by Rodrigo3H
Sat Nov 02, 2019 10:33 pm
Forum: Lewis Structures
Topic: Delocalized Electrons
Replies: 4
Views: 18

Delocalized Electrons

Can someone explain what delocalized electrons are and maybe provide an example? Thank you!
by Rodrigo3H
Sun Oct 27, 2019 10:38 am
Forum: Trends in The Periodic Table
Topic: atomic Radii
Replies: 11
Views: 39

Re: atomic Radii

Yes! More electrons means more shells which means bigger atomic radius! But remember to take into consideration the growing number of protons as you go across the periodic table.
by Rodrigo3H
Sun Oct 27, 2019 10:36 am
Forum: Trends in The Periodic Table
Topic: Question on 1E.5
Replies: 2
Views: 16

Re: Question on 1E.5

B) s electrons tend to be better at shielding because they are closer to the nucleus. D) effective nuclear charge is the net positive charge experienced by VALENCE electrons. Think about it this way, if there are more shielding electrons between the nucleus and the outer shell, the net positive char...
by Rodrigo3H
Sun Oct 27, 2019 10:27 am
Forum: Resonance Structures
Topic: Delocalized electrons
Replies: 2
Views: 14

Re: Delocalized electrons

When we talk about delocalized electrons, we are talking about the fact that there is more volume which allows for electrons to occupy a space more evenly. We draw a circle inside the lewis structure to represent that the electrons are equally likely to be anywhere along the chemical bond.
by Rodrigo3H
Sun Oct 27, 2019 10:24 am
Forum: Ionic & Covalent Bonds
Topic: 2A.23
Replies: 5
Views: 35

Re: 2A.23

a) Mg3As2
b) In2S3
c) AlH3
d) H2Te
e) BiF3
by Rodrigo3H
Sun Oct 27, 2019 10:22 am
Forum: Ionic & Covalent Bonds
Topic: Cation
Replies: 23
Views: 116

Re: Cation

Cations are positively charged ions. Anions are negatively charged ions. The important thing to know about them is that cations tend to lose their electrons and anions gain those electrons.
by Rodrigo3H
Sun Oct 20, 2019 2:10 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Pauli Exclusion Principle
Replies: 9
Views: 40

Re: Pauli Exclusion Principle

The Pauli Exclusion Principle basically states that no more than 2 electrons can occupy the same orbital at once and if an orbital does have 2 electrons, the spin will be paired.
by Rodrigo3H
Sun Oct 20, 2019 2:04 pm
Forum: *Shrodinger Equation
Topic: Wave Function
Replies: 3
Views: 34

Re: Wave Function

I think the wave function is meant to represent the orbitals, not a particular particle.
by Rodrigo3H
Sun Oct 20, 2019 1:59 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Indeterminacy
Replies: 1
Views: 13

Indeterminacy

Quick question: when we solve problems using the Heisenberg equation, we use the +/- value that comes after the given velocity or momentum value right? (For example, if we were given 5 m/s + or - 1m/s, we would use the +/- 1 m/s in the calculation correct?)
by Rodrigo3H
Sun Oct 20, 2019 1:53 pm
Forum: DeBroglie Equation
Topic: Mass of electron and photon
Replies: 5
Views: 38

Re: Mass of electron and photon

Dr. Lavelle said that the mass of an electron was known, so I'm pretty sure it will be given. Photons do not have mass.
by Rodrigo3H
Sun Oct 20, 2019 1:49 pm
Forum: DeBroglie Equation
Topic: 1B.7 HW prob
Replies: 3
Views: 27

Re: 1B.7 HW prob

For this problem, you have to remember that one sodium atom generates one photon, so the energy you calculate in part a is the same as the energy emitted by one sodium atom when it generates a photon. Knowing this just use the conversion (answer to part a in Joules)/1atom Na to find the answers to p...
by Rodrigo3H
Sat Oct 12, 2019 7:58 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation Alternatives?
Replies: 4
Views: 35

Re: Rydberg Equation Alternatives?

Hi! If you look in the textbook, you can find an equation that will help you find what you need! I think the equation was

but please double check to make sure!
by Rodrigo3H
Sat Oct 12, 2019 7:53 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atom Spectroscopy
Replies: 2
Views: 36

Atom Spectroscopy

For the sake of this class, will we only focus on the Hydrogen atom mode?
by Rodrigo3H
Sat Oct 12, 2019 7:49 pm
Forum: Properties of Light
Topic: Homework 1A 15
Replies: 2
Views: 27

Re: Homework 1A 15

Hi! I know you have to use the Rydberg equation to solve this problem. I don't recall if our professor showed us the equation in class.
by Rodrigo3H
Sat Oct 12, 2019 7:41 pm
Forum: Properties of Light
Topic: Speed of Light
Replies: 41
Views: 789

Re: Speed of Light

The speed of light is a constant so you don't have to worry about it changing.
by Rodrigo3H
Sat Oct 12, 2019 7:33 pm
Forum: Properties of Light
Topic: 1A #11
Replies: 3
Views: 25

Re: 1A #11

I had trouble with this question too! To put it rather simply, the lines are all grouped into a "series" based off of what lower energy level they are dropping down to and therefore how much energy they are emitting (photon). It's important to note that each frequency of light is associate...
by Rodrigo3H
Sat Oct 05, 2019 6:58 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Accuracy v Precision
Replies: 11
Views: 72

Re: Accuracy v Precision

Accuracy is how close your answer is to the "correct answer," and precision is how consistent two or more of your answers are.
by Rodrigo3H
Sat Oct 05, 2019 6:52 pm
Forum: Empirical & Molecular Formulas
Topic: Diatomic Molecules Vs. Ions
Replies: 2
Views: 31

Diatomic Molecules Vs. Ions

Basically, in some of the questions that we are solving, we are just given the written out name of a molecule. Since this is the case, do we always assume that Nitrogen, Oxygen, hydrogen, etc. are always diatomic?
by Rodrigo3H
Sat Oct 05, 2019 6:46 pm
Forum: Empirical & Molecular Formulas
Topic: Writing Empirical Formulas
Replies: 8
Views: 95

Re: Writing Empirical Formulas

I actually asked the TA this question and he said that the order of the elements doesn't necessarily matter as long as you have the correct subscripts and ratios for each atom. But just for a reference, if it is an ionic substance start with the metal and then the nonmetal(s), if it is an organic co...
by Rodrigo3H
Sat Oct 05, 2019 6:39 pm
Forum: Molarity, Solutions, Dilutions
Topic: Thought Process to G.7
Replies: 1
Views: 25

Re: Thought Process to G.7

To summarize G7, the problem is pretty much asking you to find the real mass of KNO3 in a 510.g aqueous solution. They tell you that KNO3 is 5.45% of 510.g so that's a clue to find the mass of KNO3 in the solution. Furthermore, it's important to remember that the solution is aqueous which means that...
by Rodrigo3H
Sat Oct 05, 2019 6:27 pm
Forum: Limiting Reactant Calculations
Topic: % yield
Replies: 5
Views: 48

Re: % yield

If we are asked to find a solution from a limiting reactant problem, for example, we will most often be evaluating the theoretical yield unless the problem explicitly states otherwise. Actual yield is what we get from the experiment that was conducted and will be less than the theoretical yield unle...
by Rodrigo3H
Sat Oct 05, 2019 6:21 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity and Dilution G23
Replies: 3
Views: 46

Molarity and Dilution G23

G23) A lab technician has made up 100.0 mL of a solution containing 0.50g NaCl and 0.30g KCl, as well as glucose and other sugars. What is the concentration of chloride ions in the solution? I understand that I need to find a solution that is in L/mol (molarity) and to do that, I have to convert 0.5...

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