Search found 54 matches

by Lauren Bui 1E
Sat Dec 07, 2019 3:07 pm
Forum: Conjugate Acids & Bases
Topic: what materials to cover for final
Replies: 2
Views: 89

Re: what materials to cover for final

i dont think we need to know buffer solutions. the final is cumulative so everything from the notes is fair game!
by Lauren Bui 1E
Sat Dec 07, 2019 3:05 pm
Forum: Lewis Structures
Topic: Lewis Structures
Replies: 2
Views: 152

Re: Lewis Structures

the least electronegative atom is typically the central molecule. hydrogens will always be on the outside since they can only form one bond. make sure to know specific trends (such as how carbon always wants to make 4 bonds to keep the FC at 0)
by Lauren Bui 1E
Sat Dec 07, 2019 3:01 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: edta
Replies: 2
Views: 39

Re: edta

there are 6 atoms with lone pairs in edta that can bond to other molecules or ions
by Lauren Bui 1E
Sat Dec 07, 2019 1:50 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: strong acids
Replies: 1
Views: 33

strong acids

Why is formic acid (HCOOH) stronger than acetic acid (CH3COOH)?
by Lauren Bui 1E
Tue Dec 03, 2019 3:41 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pH, pKa, pKb
Replies: 5
Views: 86

Re: pH, pKa, pKb

pKa and pKb measures the strength of an acid or base respectively, whereas pH specifically measures the concentration of hydrogen ions in solution
by Lauren Bui 1E
Tue Dec 03, 2019 3:38 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: calculating pH
Replies: 4
Views: 59

Re: calculating pH

first convert the moles of the solution into moles of H+ or OH- depending on if it is an acid or base, respectively, using the molar ratios. then find the molarity of the solution. plug the molarity into pOH = -log[OH-] or pH = -log[H+] if it is a base, you will need to subtract to get pH: 14-pOH = pH
by Lauren Bui 1E
Sun Dec 01, 2019 4:11 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Oxalate
Replies: 2
Views: 19

Re: Oxalate

2 of the 4 oxygen atoms have a -1 formal charge in oxalate. Does this play a role in deciding where the binding sites are?
by Lauren Bui 1E
Sun Dec 01, 2019 4:08 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: drawing a chelate
Replies: 2
Views: 52

drawing a chelate

when you are given a chemical formula, how do you draw the right structure to tell if it is a chelate? how can you tell?
by Lauren Bui 1E
Sun Dec 01, 2019 4:02 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Rule for Polydentates
Replies: 1
Views: 40

Rule for Polydentates

Is there a rule for differentiating between mono, bi, and polydentates? What is the relationship between mono/bi/polydentates and lone pairs as well as charges on molecules with lone pairs?
by Lauren Bui 1E
Sun Dec 01, 2019 3:54 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Oxalate
Replies: 2
Views: 19

Oxalate

Why is oxalate bidentate?
by Lauren Bui 1E
Sun Dec 01, 2019 2:48 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Are complex ions the same as coordination compounds?
Replies: 3
Views: 29

Re: Are complex ions the same as coordination compounds?

i believe both have ligands. If the coordination compound has a net charge, the compound is called a complex ion.
by Lauren Bui 1E
Sun Dec 01, 2019 2:43 pm
Forum: Naming
Topic: Names of ligands
Replies: 4
Views: 46

Re: Names of ligands

yes, memorizing the names of ligands is important because we will probably be asked to name compounds on our final
by Lauren Bui 1E
Sun Nov 24, 2019 10:02 pm
Forum: Lewis Acids & Bases
Topic: 6A.3
Replies: 1
Views: 34

6A.3

Hi, can someone please explain 6A.3? Thanks!
by Lauren Bui 1E
Sun Nov 24, 2019 9:57 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: 9c3
Replies: 1
Views: 52

9c3

can someone please explain how to do 9c.3 on the homework? thank you!!
by Lauren Bui 1E
Sun Nov 24, 2019 9:52 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: bronsted acid
Replies: 5
Views: 58

bronsted acid

can someone please explain what a bronsted acid is?
by Lauren Bui 1E
Tue Nov 19, 2019 12:04 pm
Forum: Bond Lengths & Energies
Topic: Boiling point
Replies: 11
Views: 286

Re: Boiling point

larger molar mass means a larger boiling point
by Lauren Bui 1E
Tue Nov 19, 2019 12:03 pm
Forum: Hybridization
Topic: test 2
Replies: 6
Views: 73

Re: test 2

i dont think so. I think everything after the midterm up to sigma and pi bonds will be on the test.
by Lauren Bui 1E
Sun Nov 17, 2019 3:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: lone pairs
Replies: 3
Views: 32

lone pairs

why do lone pairs have to be across from each other if there are multiple?
by Lauren Bui 1E
Sun Nov 17, 2019 3:29 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR repulsion model
Replies: 8
Views: 119

VSEPR repulsion model

How does repulsion play a role in the VSEPR model and how is it calculated?
by Lauren Bui 1E
Sun Nov 17, 2019 3:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 2
Views: 29

Re: Bond Angles

this was helpful, thank you!
by Lauren Bui 1E
Sun Nov 17, 2019 3:24 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Can there be lone pairs on the central atom if the shape is linear?
Replies: 4
Views: 40

Re: Can there be lone pairs on the central atom if the shape is linear?

I believe this would make the shape bent. For example, both H20 and SO2 have lone pairs on the central atom; thus, the shape is bent.
by Lauren Bui 1E
Sun Nov 17, 2019 3:22 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSERP Theory
Replies: 1
Views: 17

Re: VSERP Theory

The bonds will be covalent because sulfur and oxygen are both gases. the shape will be bent because there are 18 valence electrons and a lone pair will be added to sulfur.
by Lauren Bui 1E
Sun Nov 17, 2019 3:17 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 2
Views: 29

Bond Angles

Are we expected to memorize bond angle values? How can you tell that H20 has a bond angle of exactly 104.5?
by Lauren Bui 1E
Sun Nov 17, 2019 3:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Distortion
Replies: 2
Views: 40

Re: Distortion

distorting refers to rearranging the electron cloud. smaller, highly charger cations cause distortion, while larger atoms (with larger electron clouds) get distorted
by Lauren Bui 1E
Thu Nov 07, 2019 1:08 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability of Anions
Replies: 3
Views: 38

Re: Polarizability of Anions

More negatively charged anions typically means there is a bigger electron cloud. Since it is larger, it can be more easily distorted; thus more polarizable.
by Lauren Bui 1E
Thu Nov 07, 2019 1:05 pm
Forum: Bond Lengths & Energies
Topic: Bond lengths in resonance structures
Replies: 2
Views: 33

Re: Bond lengths in resonance structures

In resonance structures, you should take the average of the bonds so they are equivalent
by Lauren Bui 1E
Wed Nov 06, 2019 3:34 pm
Forum: Lewis Structures
Topic: Expanded Octet
Replies: 10
Views: 101

Re: Expanded Octet

some elements, especially beyond the 3rd period, can have an extended octet (aka hypervalency). for example, in the 4s block, the 3d is not full yet and can accept more electrons.
by Lauren Bui 1E
Wed Nov 06, 2019 12:24 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: smaller cations
Replies: 3
Views: 45

smaller cations

How can you tell what the smallest cation is? Is it based on charge or size/atomic radii or something else?
by Lauren Bui 1E
Fri Nov 01, 2019 9:04 pm
Forum: Properties of Light
Topic: Which equations can you only use for light?
Replies: 2
Views: 56

Re: Which equations can you only use for light?

Yes, these are equations for light only (no mass is involved)! If you are measuring wavelike properties (for things with mass), use de broglie's equation.
by Lauren Bui 1E
Fri Nov 01, 2019 8:59 pm
Forum: Trends in The Periodic Table
Topic: Octet Rules
Replies: 4
Views: 46

Re: Octet Rules

If an atom does not satisfy the octet rule, it means there are less than 8 electrons (i.e. the first 4 elements of the periodic table). An expanded octet refers to when there are more than 8 electrons; these are also known as exceptions to the octet rule.
by Lauren Bui 1E
Fri Nov 01, 2019 8:33 pm
Forum: Lewis Structures
Topic: Determining lowest energy lewis structure
Replies: 2
Views: 28

Determining lowest energy lewis structure

Is there a strategy for drawing the lowest energy lewis structure or do you have to guess and check? Are there any tips for rearranging the structure to have the lowest formal charge?
by Lauren Bui 1E
Fri Nov 01, 2019 8:30 pm
Forum: Bond Lengths & Energies
Topic: Bond length and strength
Replies: 3
Views: 45

Bond length and strength

What is the relationship between bond length and bond strength? and is there a reason for this relationship?
by Lauren Bui 1E
Fri Nov 01, 2019 8:22 pm
Forum: Lewis Structures
Topic: central atom
Replies: 16
Views: 1437

central atom

When drawing a lewis structure, how do you determine which atom goes in the center?
by Lauren Bui 1E
Sun Oct 27, 2019 8:52 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity on the Test
Replies: 3
Views: 28

Re: Electron Affinity on the Test

I wouldn't focus on solving for the actual affinity quantity, although I'm not 100% sure. I think it is definitely important to understand the conceptual ideas.
by Lauren Bui 1E
Sun Oct 27, 2019 8:44 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Chromium and Copper
Replies: 5
Views: 55

Re: Chromium and Copper

For chromium and copper, a completely full (d10) or half full (d5) d sub-level is more stable than a partially filled d sub-level. As a result, an electron from the 4s orbital is excited and rises to a 3d orbital, because this reduces the total energy
by Lauren Bui 1E
Sun Oct 27, 2019 8:42 pm
Forum: Ionic & Covalent Bonds
Topic: Metals Vs. Nonmetals
Replies: 8
Views: 200

Re: Metals Vs. Nonmetals

metals tend to form cations and nonmetals tend to form anions. metals tend to lose electrons to achieve noble gas configuration, because they typically have 1, 2, or 3 electrons. because nonmetals have 5, 6, or 7 electrons in their valence shell, it requires less energy to gain the necessary electro...
by Lauren Bui 1E
Sun Oct 27, 2019 8:37 pm
Forum: Trends in The Periodic Table
Topic: F orbital
Replies: 3
Views: 42

Re: F orbital

I believe Dr. Lavelle said we did not need to use the F orbital for this class, so I would focus on the s, p, and d orbitals
by Lauren Bui 1E
Sun Oct 27, 2019 8:36 pm
Forum: Resonance Structures
Topic: Delocalization
Replies: 6
Views: 87

Re: Delocalization

I think it refers to electrons that are not paired with a single atom or covalent bond.
by Lauren Bui 1E
Sun Oct 20, 2019 2:45 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodal Planes
Replies: 6
Views: 45

Re: Nodal Planes

In the s-orbital, electorns have no angular momentum (l = 0), so they're distributed around the nucleus instead of circulating it. In p-,d-, and f- orbitals, electrons have angular momentum (l>0), and the spherical movement creates nodal planes.
by Lauren Bui 1E
Sun Oct 20, 2019 2:37 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Frequencies
Replies: 7
Views: 175

Re: Frequencies

I think it would be helpful to know the order from shortest wavelength to longest wavelength (gamma, x-ray, UV, visible, infared, radio).
This is what I was told in one of the workshops at least :)
by Lauren Bui 1E
Sun Oct 20, 2019 2:31 am
Forum: *Shrodinger Equation
Topic: Shrodinger Equation
Replies: 3
Views: 53

Shrodinger Equation

Is it important to know how to derive this equation? If so, how do you do that?
by Lauren Bui 1E
Sun Oct 20, 2019 2:24 am
Forum: Quantum Numbers and The H-Atom
Topic: Angular Momentum Quantum #
Replies: 3
Views: 44

Angular Momentum Quantum #

Where does the angular momentum quantum number come from?
by Lauren Bui 1E
Sun Oct 20, 2019 1:25 am
Forum: Quantum Numbers and The H-Atom
Topic: Angular Wavefunctions
Replies: 2
Views: 46

Re: Angular Wavefunctions

I don't think so. I wouldn't focus too much on it
by Lauren Bui 1E
Sun Oct 13, 2019 8:08 pm
Forum: Einstein Equation
Topic: E=hv
Replies: 5
Views: 96

Re: E=hv

yes it can be used to calculate the energy necessary to remove an electron, but be sure to read the problem closely
by Lauren Bui 1E
Sun Oct 13, 2019 8:01 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Angstrom's Constant
Replies: 5
Views: 191

Re: Angstrom's Constant

You can use dimensional analysis to set up a conversion from Angstroms to another SI unit, just like you would from one SI unit to another.
by Lauren Bui 1E
Sun Oct 13, 2019 7:58 pm
Forum: Photoelectric Effect
Topic: Threshold Energy
Replies: 4
Views: 64

Re: Threshold Energy

From my understanding, the threshold energy should vary for different elements
by Lauren Bui 1E
Sun Oct 13, 2019 7:51 pm
Forum: Photoelectric Effect
Topic: De Broglie's Equation
Replies: 5
Views: 37

De Broglie's Equation

When do I use De Broglie's equation?
by Lauren Bui 1E
Sun Oct 13, 2019 7:45 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity and Molality
Replies: 2
Views: 178

Re: Molarity and Molality

Molarity (M) is the number of moles of solute per liter of solution whereas molality (m) is defined as the number of moles of solute per kilogram of solvent, not solution.
by Lauren Bui 1E
Sun Oct 06, 2019 5:37 pm
Forum: Limiting Reactant Calculations
Topic: % yield
Replies: 5
Views: 80

Re: % yield

the actual yield must be a given value or a value found from an experiment! if you're asked to find the %yield, the question will typically give you the actual yield value
by Lauren Bui 1E
Sun Oct 06, 2019 5:33 pm
Forum: SI Units, Unit Conversions
Topic: Formula Units
Replies: 3
Views: 56

Re: Formula Units

That clears things up a lot! Thank you :)
by Lauren Bui 1E
Sun Oct 06, 2019 5:32 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: sig figs
Replies: 20
Views: 276

Re: sig figs

you should use exact values from the periodic table and avoid rounding or using sig figs until the very end. this will minimize rounding error :)
by Lauren Bui 1E
Sun Oct 06, 2019 5:30 pm
Forum: Balancing Chemical Reactions
Topic: Naming compounds
Replies: 2
Views: 65

Re: Naming compounds

I think it would be beneficial to memorize the most commonly seen compounds, just to be safe :)
by Lauren Bui 1E
Sun Oct 06, 2019 5:26 pm
Forum: Balancing Chemical Reactions
Topic: Alternative to Guess and Check?
Replies: 5
Views: 70

Re: Alternative to Guess and Check?

I usually begin to balance an equation by starting from the left side of the reactants side. So I first would balance sulfur, then hydrogen, etc. In this case, sulfur would be balanced, but by adjusting the hydrogen levels, you would have to go back and adjust the level of sulfur. This method still ...
by Lauren Bui 1E
Sun Oct 06, 2019 5:11 pm
Forum: SI Units, Unit Conversions
Topic: Formula Units
Replies: 3
Views: 56

Formula Units

What exactly are formula units?

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