Search found 50 matches

by Lilyana Villa 1J
Sat Dec 07, 2019 11:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AXE formula
Replies: 7
Views: 214

Re: AXE formula

The E of the VSEPER formula represents the number of lone pairs the central atom has.
by Lilyana Villa 1J
Sat Dec 07, 2019 11:32 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: different forces
Replies: 1
Views: 94

Re: different forces

The forces of intermolecular forces we should know are London forces, which are present among any molecule (and the weakest), dipole-dipole (stronger than London), which is present in polar molecules, and hydrogen bonding, which is the strongest type of dipole dipole force.
by Lilyana Villa 1J
Sat Dec 07, 2019 11:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent molecules
Replies: 1
Views: 95

Re: Bent molecules

All molecules with a bent shape are polar because even though the dipole moments of the two bonded atoms go towards the bonded atoms and not the central, it doesn't cancel because the bonded atoms are not opposite one another.
by Lilyana Villa 1J
Sat Dec 07, 2019 11:10 pm
Forum: Coordinate Covalent Bonds
Topic: Cisplatin
Replies: 3
Views: 138

Re: Cisplatin

All you really need to know is just that cisplatin is a chemotherapy drug whose two Cl ligands bind to guanine in order to prevent the DNA polymerase from attaching to guanine. So pretty much exactly what you said.
by Lilyana Villa 1J
Sat Dec 07, 2019 10:43 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: base constants
Replies: 1
Views: 42

Re: base constants

No, you do not need to memorize the base constants, but you need to know how to calculate them when given other values like pKa, pKb, etc.
by Lilyana Villa 1J
Sun Dec 01, 2019 11:20 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: charge and coordination number
Replies: 2
Views: 21

Re: charge and coordination number

I don't believe there is a relationship between charge and coordination number.
by Lilyana Villa 1J
Sun Dec 01, 2019 11:12 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Determing Coordination Number
Replies: 5
Views: 44

Re: Determing Coordination Number

The coordination number corresponds to the number of bonds around the central atom. I think this is the only way but its very easy so you don't need to use another method.
by Lilyana Villa 1J
Sun Dec 01, 2019 11:04 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Shapes and Corners
Replies: 2
Views: 28

Re: Shapes and Corners

I'm pretty sure there can be both odd and even numbers of ligands around a central atom. It's not common but its possible.
by Lilyana Villa 1J
Sun Dec 01, 2019 10:58 pm
Forum: Resonance Structures
Topic: Carbon
Replies: 4
Views: 153

Re: Carbon

A regular carbon atom can never hold more than 8 electrons in its valence shell. It isn't included in the elements that are able to have an expanded octet.
by Lilyana Villa 1J
Sun Dec 01, 2019 10:54 pm
Forum: Lewis Acids & Bases
Topic: Conjugates
Replies: 3
Views: 29

Re: Conjugates

A conjugate acid is a base that was donated a hydrogen ion and a conjugate base is an acid with one less hydrogen ion.
by Lilyana Villa 1J
Sun Nov 24, 2019 11:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular shape of carbon Dioxide
Replies: 10
Views: 100

Re: Molecular shape of carbon Dioxide

The molecular shape of carbon dioxide would be linear with a bond angle of 180 degrees since there are 2 regions of electron density with no lone pairs.
by Lilyana Villa 1J
Sun Nov 24, 2019 11:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: t shape and see saw
Replies: 6
Views: 87

Re: t shape and see saw

The difference between trigonal bipyramidal and seesaw is that seesaw has one lone pair and 4 bonded atoms while trigonal bipyramidal has 5 bonded atoms w/ no lone pairs. For tetrahedral and t-shaped, tetrahedral is a shape with 4 regions of electron density (4 bonded atoms w/ no lone pairs) and t s...
by Lilyana Villa 1J
Sun Nov 24, 2019 11:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 7
Views: 104

Re: Bond Angles

The reason why some molecules have bond angles that are "smaller" than the value of the general shape is because they have lone pairs. Molecules with lone pairs will have angles that are smaller than a given value because lone pairs have a stronger repelling effect than bonded electrons, w...
by Lilyana Villa 1J
Sun Nov 24, 2019 11:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hydrogen Bonding
Replies: 2
Views: 44

Hydrogen Bonding

Okay so I'm confused about hydrogen bonding sites. For example, if a nitrogen was already bonded to a hydrogen but still had a lone pair of electrons, would that nitrogen still be considered a hydrogen bonding site for a new hydrogen bond or would it not since it is already bonded to a hydrogen?
by Lilyana Villa 1J
Sun Nov 24, 2019 11:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: T-shape
Replies: 21
Views: 379

Re: T-shape

A tshaped molecule is a molecule that has 2 lone pairs and 3 bonded atoms. The bond angles would be less than 90 degrees.
by Lilyana Villa 1J
Sun Nov 17, 2019 9:09 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Equatorial lone pairs
Replies: 2
Views: 33

Re: Equatorial lone pairs

The lone pair comes from the equatorial plane because the lowest energy is achieved when a lone pair is equatorial rather than an axial lone pair. An equatorial lone pair would only repel the 2 axial bonds while an axial lone pair would repel the 3 equatorial bonds.
by Lilyana Villa 1J
Sun Nov 17, 2019 8:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular shape
Replies: 3
Views: 26

Re: Molecular shape

I believe sawhorse is just another name for seesaw, so yes they both refer to the same shape. However, seesaw will be the name that we'd use on homework and exams.
by Lilyana Villa 1J
Sun Nov 17, 2019 8:15 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shapes
Replies: 6
Views: 64

Re: Molecular Shapes

For the test and final, yes we need to memorize all of them because it'll be likely that we'll be given the more complex ones on the exams like seesaw and t-shaped.
by Lilyana Villa 1J
Sun Nov 17, 2019 8:14 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 3
Views: 39

Bond Angles

Is there any circumstance where the bond angles of molecules w/ lone pairs will be greater than the angle of the general shape? Or will the bond angle always be smaller?
by Lilyana Villa 1J
Sun Nov 17, 2019 8:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles for molecules w/ multiple central atoms
Replies: 1
Views: 44

Bond Angles for molecules w/ multiple central atoms

How do we determine the bond angles for molecules with more than 1 central atom? I know we are supposed to treat each central atom as its own but would the bond angles be the exact same as the general shape or...?
by Lilyana Villa 1J
Sun Nov 10, 2019 10:39 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability
Replies: 4
Views: 69

Re: Polarizability

Larger atoms have high polarizability because they tend to have more loosely held electrons while smaller atoms tend to hold electrons more closely. This makes it easier for their electrons to become distorted by a cation.
by Lilyana Villa 1J
Sun Nov 10, 2019 10:34 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: polarizability and polarizing power
Replies: 4
Views: 69

Re: polarizability and polarizing power

When a cation has high polarizing power, it has the ability to cause high electron distortion. The smaller the cation and the higher electronegativity it has, the more polarizing power it has. If you were to look at the s block, the cations on the topmost right will have the most polarizing power du...
by Lilyana Villa 1J
Sun Nov 10, 2019 10:23 pm
Forum: Lewis Structures
Topic: Bonds
Replies: 4
Views: 43

Re: Bonds

You must take into account how many electrons each atom needs in order to have an octet (keep in mind those who can have expanded octets), while also keeping track of the formal charge in order to make a Lewis structure with the lowest energy. Also something to keep in mind is that triple bonds are ...
by Lilyana Villa 1J
Tue Nov 05, 2019 7:18 pm
Forum: Lewis Structures
Topic: Homework Problem 2C. 3c
Replies: 1
Views: 39

Homework Problem 2C. 3c

3. Draw the Lewis structure, including typical contributions to the resonance structure (where appropriate, allow for the possibility of octet expansion, including double bonds in different positions), (c) chloric acid. For this question, I thought I did it right but then when I compared my answer t...
by Lilyana Villa 1J
Sun Nov 03, 2019 11:31 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration
Replies: 3
Views: 59

Re: Electron Configuration

I believe this is because electrons in the outermost shell (valence electrons) are easier to remove since electrons closer to the nucleus are more tightly held. Electrons in the highest orbital are in the outermost shell.
by Lilyana Villa 1J
Sun Nov 03, 2019 11:22 pm
Forum: Quantum Numbers and The H-Atom
Topic: Magnetic Quantum Number
Replies: 3
Views: 39

Re: Magnetic Quantum Number

The magnetic quantum number should always be plus or minus 1/2.
by Lilyana Villa 1J
Sun Nov 03, 2019 11:17 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Atomic Orbitals
Replies: 4
Views: 157

Atomic Orbitals

According to the Quantum World outline, we are supposed to be able to "describe the interpretation of atomic orbitals in terms of probability." What does this mean? Can some explain?
by Lilyana Villa 1J
Sun Nov 03, 2019 11:11 pm
Forum: Trends in The Periodic Table
Topic: Midterm Question Regarding Metals, Nonmetals, etc
Replies: 2
Views: 38

Midterm Question Regarding Metals, Nonmetals, etc

For the midterm, do we need to be able to identify if an element is a metal, nonmetal, metalloid, etc?
by Lilyana Villa 1J
Sun Nov 03, 2019 7:57 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Homework Problem 1E. 5
Replies: 2
Views: 56

Homework Problem 1E. 5

1E. 5) Which of the following statements are true for many-electron atoms? If false, explain why. (a) The effective nuclear charge Zeffe is independent of the number of electrons present in an atom. I know the answer is false but I can't explain why. Can someone explain why it's false?
by Lilyana Villa 1J
Sun Oct 27, 2019 10:37 pm
Forum: Resonance Structures
Topic: Arrangement of Atoms
Replies: 3
Views: 34

Arrangement of Atoms

How is formal charge used to predict the arrangement of atoms in a molecule?
by Lilyana Villa 1J
Sun Oct 27, 2019 10:32 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 3
Views: 61

Resonance Structures

Can someone give me an explanation on why we have to create resonance structures for some molecules instead of just a single lewis structure?
by Lilyana Villa 1J
Sun Oct 27, 2019 10:28 pm
Forum: Lewis Structures
Topic: Formal Charge [ENDORSED]
Replies: 6
Views: 81

Formal Charge [ENDORSED]

Can someone explain what formal charge is and how you calculate it? Thank you
by Lilyana Villa 1J
Sun Oct 27, 2019 10:25 pm
Forum: Resonance Structures
Topic: Kekule Structure
Replies: 2
Views: 37

Kekule Structure

Can someone explain to me what a kekule structure is?
by Lilyana Villa 1J
Sun Oct 27, 2019 9:55 pm
Forum: Lewis Structures
Topic: 2C.1
Replies: 2
Views: 41

Re: 2C.1

B and C are the radicals since they have an unpaired electron.
by Lilyana Villa 1J
Sun Oct 20, 2019 11:56 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Short Hand or Normal Way?
Replies: 3
Views: 71

Short Hand or Normal Way?

When writing electron configurations, are we allowed to write configurations in short hand or do we need to write out the whole configuration on assignments/test?
by Lilyana Villa 1J
Sun Oct 20, 2019 11:49 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Spin
Replies: 8
Views: 93

Re: Electron Spin

According to Pauli Exclusion Principle, when two electrons do occupy one orbit, their spins must be paired. Electrons have parallel spins when they occupy different orbitals and must not be paired unless all of the orbitals have at least 1 electron in each.
by Lilyana Villa 1J
Sun Oct 20, 2019 11:36 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Homework 1E.7
Replies: 3
Views: 51

Re: Homework 1E.7

I believe part C violates Aufbau's Principle because the 2s orbital must be occupied with 2 electrons with parallel spins before electrons can be arranged into the 2p orbital. There's 1 electron in the 2s orbital and 1 electron in the 2p orbital.
by Lilyana Villa 1J
Sun Oct 20, 2019 11:01 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Clarification on electron configuration
Replies: 5
Views: 57

Clarification on electron configuration

In his lecture, Lavelle said we only needed to know the electron configurations of atoms in a certain blocks. I know he said s-block and p-block, but I don't know how many rows of the d-block he said we are supposed to know. Does anyone remember?
by Lilyana Villa 1J
Sun Oct 20, 2019 10:43 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Excited State
Replies: 3
Views: 45

Excited State

How can you determine whether an atom is in an excited state based on the electron configuration?
by Lilyana Villa 1J
Sun Oct 13, 2019 11:53 pm
Forum: Properties of Light
Topic: 1B. 3
Replies: 2
Views: 36

1B. 3

I'm not 100% sure if my question falls under Properties of Light but here it is: From the following list of observations, select the one that best supports the idea that electromagnetic radiation has the properties of particles. Explain your reasoning. (a) Black-body radiation (b) electron different...
by Lilyana Villa 1J
Sun Oct 13, 2019 11:34 pm
Forum: Properties of Light
Topic: Lyman Series & Balmer Series
Replies: 4
Views: 51

Lyman Series & Balmer Series

What is the difference between the Balmer Series and Lyman Series?
by Lilyana Villa 1J
Sun Oct 13, 2019 11:18 pm
Forum: Properties of Light
Topic: Energy Equation
Replies: 3
Views: 36

Re: Energy Equation

I believe h is Planck's Constant
by Lilyana Villa 1J
Sun Oct 13, 2019 11:15 pm
Forum: Properties of Light
Topic: 1A. 11
Replies: 1
Views: 64

1A. 11

Q. A photon generated as a result of which of the following transitions in the hydrogen atom will have the greatest energy? Explain your answer. (a) From n=6 to n=5
I think I remember this from lecture but I don't understand the logic behind it. Can someone explain?
by Lilyana Villa 1J
Sun Oct 13, 2019 10:50 pm
Forum: Properties of Light
Topic: Homework Problem 1A. 15
Replies: 1
Views: 34

Homework Problem 1A. 15

Q. In the ultraviolet spectrum of atomic hydrogen, a line is observed at 102.6 nm. Determine the values of n for the initial and final energy levels of the electron during the emission of energy that leads to this spectral line. I have no clue what I am supposed to do for this problem.
by Lilyana Villa 1J
Thu Oct 03, 2019 11:51 pm
Forum: SI Units, Unit Conversions
Topic: scientific notation
Replies: 7
Views: 80

Re: scientific notation

I think it's up to you if you want to put your answer in scientific notation or not. I don't think you'll be docked points if you do or don't use scientific notation, but it is probably recommended when you are dealing with very large or small numbers like 150,000 or 0.0005. My best answer is use yo...
by Lilyana Villa 1J
Thu Oct 03, 2019 11:42 pm
Forum: SI Units, Unit Conversions
Topic: Formula Units
Replies: 3
Views: 83

Re: Formula Units

I believe formula units is just another word for atoms or molecules, depending on the context of the problem (like if the formula given depicts a molecule or an atom). I was confused on this question too about the formula units but when I checked the solutions manual, there wasn't anything in the gi...
by Lilyana Villa 1J
Thu Oct 03, 2019 11:33 pm
Forum: SI Units, Unit Conversions
Topic: Homework Problem E. 29
Replies: 3
Views: 69

Homework Problem E. 29

Q. A chemist measured out 8.61 g of copper (II) chloride tetrahydrate, CuCl2*4H2O. (a) How many moles of CuCl2*4H2O were measured out? b) How many moles of Cl- (the negative sign should be at the top) ions are present in the sample? I don't understand how you're supposed to do part B, can someone he...
by Lilyana Villa 1J
Thu Oct 03, 2019 10:58 pm
Forum: Empirical & Molecular Formulas
Topic: What decimal place to round to when taking masses from the Periodic Table?
Replies: 19
Views: 405

Re: What decimal place to round to when taking masses from the Periodic Table?

My recommendation is 2 to 3 decimal places. I don't think the professor is too strict on the rounding since not rounding at all is super excessive and could leave more room for error when typing it on the calculator to solve a problem.
by Lilyana Villa 1J
Thu Oct 03, 2019 6:57 pm
Forum: SI Units, Unit Conversions
Topic: Formula Names
Replies: 7
Views: 86

Formula Names

Does anyone know if we are required to know how to write out formulas when only given the formula name (ex. magnesium nitrate)? I never remember how to write out endings like sulfate and nitrate on the spot.

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