Search found 62 matches

by Selena Yu 1H
Thu Jan 16, 2020 12:42 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: kA and kB
Replies: 2
Views: 7

kA and kB

The lower pKa and pKb, the stronger the acid and base. Does that mean the higher the kA and kB, the stronger the acid and base? Since, they are inversely related.
by Selena Yu 1H
Thu Jan 16, 2020 12:37 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Approximation
Replies: 6
Views: 21

Approximation

Why is it that if X is less than 5% of initial then approximation is okay? Like why is the cut off 5%?
by Selena Yu 1H
Thu Jan 16, 2020 12:30 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6C#9
Replies: 2
Views: 9

Re: 6C#9

You would look at the pKb values in Tables 6C.2 to determine the strength of the base. The lower the pKb, the stronger the base.
by Selena Yu 1H
Thu Jan 16, 2020 12:27 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6D.15
Replies: 1
Views: 32

Re: 6D.15

The dissociation reaction is AlCl3 + H2O --> Al(OH)3 + HCl. H2O would always be added because it is a solvent and then with that you could figure out the products. The equation above is not balanced and then HCl would dissolve into H+ and Cl- and you would use that to calculate the pH.
by Selena Yu 1H
Thu Jan 16, 2020 12:23 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Help on 5.35
Replies: 5
Views: 25

Re: Help on 5.35

It says in the problem that compound A decomposes into compounds B and C. So the chemical equation would be A (g) --> B (g) + C (g)
by Selena Yu 1H
Sun Jan 12, 2020 1:30 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Quick way
Replies: 7
Views: 32

Quick way

Why is the quick way to know whether or not the reaction shifts to the right or left for change in pressure not exactly correct according to Dr. Lavelle?
by Selena Yu 1H
Sun Jan 12, 2020 1:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K = 1
Replies: 2
Views: 11

K = 1

Why is K = 1 considered rare to achieve?
by Selena Yu 1H
Sun Jan 12, 2020 1:23 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 5I.27
Replies: 1
Views: 12

Re: 5I.27

Part c is asking for the amount of each product and reactant at equilibrium. So you would use the ICE method to figure out the concentrations of the reactants and products.
by Selena Yu 1H
Sun Jan 12, 2020 1:18 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Functions
Replies: 2
Views: 22

Re: Functions

What function you use is determined by the amount of products you have. You have to use the ICE rule to determine the equation and exponents used.
by Selena Yu 1H
Sun Jan 12, 2020 1:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pure substances in reactions
Replies: 2
Views: 18

Re: Pure substances in reactions

Yea, there can't be any reactions that only contains pure substances because two solids wouldn't mix together to create another solid as there needs to be a solvent for the reaction to occur. In most cases, the solvent would be H2O and since the concentration amount is insignificant, it is often not...
by Selena Yu 1H
Sat Dec 07, 2019 2:49 pm
Forum: Naming
Topic: (en), (dien), etc.
Replies: 6
Views: 47

Re: (en), (dien), etc.

Yes, I'm pretty sure you can use abbreviations.
by Selena Yu 1H
Sat Dec 07, 2019 2:44 pm
Forum: Student Social/Study Group
Topic: most stable
Replies: 6
Views: 41

Re: most stable

The most stable form of a Lewis structure is when all the formal charges on the molecules are zero.
by Selena Yu 1H
Sat Dec 07, 2019 2:41 pm
Forum: Conjugate Acids & Bases
Topic: Strength
Replies: 2
Views: 29

Re: Strength

No, a strong acid will have a weak conjugate base and it is the same for bases.
by Selena Yu 1H
Sat Dec 07, 2019 2:32 pm
Forum: Dipole Moments
Topic: summarize dipole dipole moments
Replies: 1
Views: 27

Re: summarize dipole dipole moments

Yea, everything you said is correct and additionally all polar molecules form dipole-dipole
by Selena Yu 1H
Sat Dec 07, 2019 2:27 pm
Forum: Biological Examples
Topic: Hemoglobin and Myoglobin
Replies: 2
Views: 31

Re: Hemoglobin and Myoglobin

Hemoglobin is made out of 4 myoglobin-like molecules. The hemoglobin binds to the 4 O2. While myoglobin is the heme complex + protein and the heme complex is Fe bound to porphyrin ligand.
by Selena Yu 1H
Sat Nov 30, 2019 2:38 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Weak Acids & Bases
Replies: 6
Views: 37

Weak Acids & Bases

What are some examples of weak acids and bases?
by Selena Yu 1H
Sat Nov 30, 2019 2:31 pm
Forum: Industrial Examples
Topic: What do we need to know?
Replies: 15
Views: 128

Re: What do we need to know?

No, cisplatin should be all we need to know for industrial examples of coordination compounds. But remember that we also need to know biological examples of coordination compounds.
by Selena Yu 1H
Sat Nov 30, 2019 2:28 pm
Forum: Naming
Topic: Water
Replies: 1
Views: 28

Re: Water

You use aqua for water when the ligand has no charge and you use dihydrate when the ligand is either a cation or anion.
by Selena Yu 1H
Wed Nov 27, 2019 8:33 pm
Forum: Hybridization
Topic: single vs double vs triple bonds
Replies: 4
Views: 28

Re: single vs double vs triple bonds

The number of bonds don't affect the hybridization because we see double and triple bonds as one region of electron density just like how we did when we determining shape using VSEPR.
by Selena Yu 1H
Wed Nov 27, 2019 4:51 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordinate covalent bonds
Replies: 4
Views: 30

Re: Coordinate covalent bonds

For coordinate covalent bonds, a lone pair is donated from the atoms, while in an ionic bond, the valence electrons are donated from the atoms. That is the difference between coordinate covalent bonds and ionic bonds.
by Selena Yu 1H
Sat Nov 23, 2019 9:30 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordinate covalent bonds
Replies: 2
Views: 15

Coordinate covalent bonds

What is the difference between coordinate covalent bonds and covalent bonds? Or is there no difference? But if there is no difference why can't we just call them covalent bonds?
by Selena Yu 1H
Sat Nov 23, 2019 9:26 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted Acids vs Lewis acids
Replies: 4
Views: 25

Bronsted Acids vs Lewis acids

What is the difference between bronsted acids and Lewis acids? Why do we need to classify acids differently?
by Selena Yu 1H
Sat Nov 23, 2019 9:23 pm
Forum: Biological Examples
Topic: Biological Applications to Know
Replies: 3
Views: 50

Re: Biological Applications to Know

You should also be aware of the function of cisplatin. And other biological applications include the importance of chromium and how it assists insulin in control of blood sugar, cobalt and how it helps with vitamin B12, and how Mn, Ni, Cu, Zn are critical for enzyme function.
by Selena Yu 1H
Sat Nov 23, 2019 9:18 pm
Forum: Hybridization
Topic: Hybridization Notation
Replies: 5
Views: 27

Re: Hybridization Notation

Yes, the d comes from the s and p orbital
by Selena Yu 1H
Sat Nov 23, 2019 9:16 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 3
Views: 25

Re: Polydentate

A ligand that is polydentate can form many bonds
by Selena Yu 1H
Sat Nov 16, 2019 2:49 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 interactions
Replies: 2
Views: 20

Dipole-dipole interactions

I'm confused about homework question 3F.3. How can you determine when dipole-dipole interactions are important? What does that even mean?
by Selena Yu 1H
Sat Nov 16, 2019 2:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Interaction Potential Energy
Replies: 3
Views: 23

Re: Interaction Potential Energy

The formula, kq1q2/r, refer to the electric potential energy which finds the potential energy between two charges. While the formula, Dr.Lavelle talked about in class refers to the interaction potential energy which finds the potential energy between two atoms.
by Selena Yu 1H
Fri Nov 15, 2019 12:17 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Other shapes
Replies: 3
Views: 22

Re: Other shapes

It might be mentioned during lecture tomorrow. I heard from my TA that the lecture tomorrow would still be included on the test
by Selena Yu 1H
Thu Nov 14, 2019 4:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2.27
Replies: 1
Views: 17

Re: 2.27

For b, a radical is a lewis structure that has an unpaired electron. So when you draw the Lewis structure and you find that you have one unpaired electron, which is usually on the central atom, then it is on a radical. Then for the increasing HCH bond angles you would have to do VSEPR theory to figu...
by Selena Yu 1H
Thu Nov 14, 2019 3:57 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 11
Views: 78

Re: Test 2

My TA said that test 2 would be everything that was not on midterm up to what we learn in class on Friday. So, things such as like dipole-dipole, intermolecular forces, and VSEPR theory.
by Selena Yu 1H
Thu Nov 14, 2019 3:50 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: 3F.13
Replies: 2
Views: 17

Re: 3F.13

First, you would try to figure out what atoms correspond to which color. So looking at the diagram, the dark grey atom would be carbon because it is the central atom. Then, the light grey atom would be hydrogen because hydrogen is smaller than chlorine. So then that leaves the green atom to be chlor...
by Selena Yu 1H
Sat Nov 09, 2019 8:37 pm
Forum: Dipole Moments
Topic: Interaction potential energy
Replies: 1
Views: 21

Interaction potential energy

Why is the interaction potential energy always negative? What makes the interaction potential energy negative?
by Selena Yu 1H
Sat Nov 09, 2019 8:32 pm
Forum: Bond Lengths & Energies
Topic: Bond Shape
Replies: 3
Views: 39

Re: Bond Shape

Molecules are polar when electrons are not equally shared and that means that there is a big difference in electronegativity between the two molecules, making one molecule more negative and the other more positive. Below, I have attached a picture showing H2O being polar. http://upload.wikimedia.org...
by Selena Yu 1H
Sat Nov 09, 2019 8:27 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: 11/8/19 Friday Lecture
Replies: 1
Views: 19

Re: 11/8/19 Friday Lecture

No, we won't be tested on the shapes of pentane and dimethylpropane. We just need to know that the rod-shaped molecules are closer together and therefore they are stronger than a spherical-shaped molecule.
by Selena Yu 1H
Sat Nov 09, 2019 8:25 pm
Forum: Bond Lengths & Energies
Topic: Bonds
Replies: 2
Views: 38

Re: Bonds

Hydrogen and covalent bonds are different things because hydrogen bonds are between molecules, while covalent bonds are between atoms. Hydrogen bonds are intermolecular forces, while covalent bonds are intramolecular forces. So we can't really compare the two for bond strength and length
by Selena Yu 1H
Sat Nov 09, 2019 6:50 pm
Forum: Bond Lengths & Energies
Topic: Hydrogen Bonding melting point
Replies: 3
Views: 29

Re: Hydrogen Bonding melting point

Hydrogen Bonding explains a higher melting point because they are a very strong intermolecular force, which means that more energy is needed to break the bond leading to a higher melting point.
by Selena Yu 1H
Sat Nov 02, 2019 12:10 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: making change in energy negative
Replies: 2
Views: 20

Re: making change in energy negative

You also make the change in energy negative because we can't have a negative energy of a photon. So instead, we make the change in energy negative.
by Selena Yu 1H
Sat Nov 02, 2019 12:07 am
Forum: Trends in The Periodic Table
Topic: Ionization Energy (10d on Midterm Review)
Replies: 3
Views: 29

Re: Ionization Energy (10d on Midterm Review)

No, you don't always have to write out the full electron configuration because you just have to know the periodic trend for ionization energy, which is that it increases from bottom to top and left to right. As for the exceptions we need to know, they are oxygen and nitrogen, where nitrogen is great...
by Selena Yu 1H
Fri Nov 01, 2019 11:59 pm
Forum: Bond Lengths & Energies
Topic: Bond strength and electronegativity
Replies: 2
Views: 27

Re: Bond strength and electronegativity

The electronegativity is the e- pulling power of an atom. So, the stronger the e- pulling power of an atom, the electronegativity, the stronger the bond strength.
by Selena Yu 1H
Fri Nov 01, 2019 11:54 pm
Forum: *Shrodinger Equation
Topic: ?
Replies: 2
Views: 66

Re: ?

The Schrodinger's wave function equation is to show that there are many solutions, which means that there are many different orbitals. I think that's all you need to know about it.
by Selena Yu 1H
Fri Nov 01, 2019 10:47 pm
Forum: Lewis Structures
Topic: Compound Names
Replies: 3
Views: 32

Re: Compound Names

You would most likely get the formula, so you wouldn't have to just know the name. But in a situation, where you would have to know the name, you would start by looking at the periodic table for the charges or you have to remember the polyatomic ions.
by Selena Yu 1H
Fri Oct 25, 2019 2:39 pm
Forum: Ionic & Covalent Bonds
Topic: Identifying Ionic vs Covalent
Replies: 7
Views: 53

Re: Identifying Ionic vs Covalent

You can identify that a bond is ionic because electrons are being transferred from metal to nonmetal atoms, while a bond is covalent because electrons are being shared instead of being transferred.
by Selena Yu 1H
Fri Oct 25, 2019 2:32 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 8
Views: 57

Drawing Lewis Structures

Is there ever an exception where you won't choose the atom with the lowest ionization energy as the central atom?
by Selena Yu 1H
Fri Oct 25, 2019 2:29 pm
Forum: Properties of Electrons
Topic: Mass of electron in 1B.15
Replies: 3
Views: 25

Re: Mass of electron in 1B.15

No, we weren't suppose to know the mass of electron. You can look it up. We would be provided this information on the test.
by Selena Yu 1H
Fri Oct 25, 2019 2:26 pm
Forum: Lewis Structures
Topic: Charges on atoms with lower e- affinity
Replies: 4
Views: 24

Re: Charges on atoms with lower e- affinity

Dr. Lavelle was saying that you shouldn't put more charges on a lower electron affinity molecule because that would make the whole lewis structure less stable, which is what you don't want.
by Selena Yu 1H
Fri Oct 25, 2019 2:21 pm
Forum: Resonance Structures
Topic: Resonance
Replies: 3
Views: 49

Re: Resonance

The bond energy is lower because it is no longer just double bonds, but rather a mixture between double bonds and single bonds, so the energy would would be lower.
by Selena Yu 1H
Fri Oct 18, 2019 2:24 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Spin Magnetic Quantum #
Replies: 6
Views: 87

Spin Magnetic Quantum #

Why is the spin magnetic quantum number only either +1/2 or -1/2? Was this found through experiments? Is it possible for it to be any other number?
by Selena Yu 1H
Fri Oct 18, 2019 2:22 am
Forum: DeBroglie Equation
Topic: 1A13
Replies: 1
Views: 14

Re: 1A13

For a, you would use the Rydberg equation to find frequency, v. The Rydberg equation would be v = R((1/(n1)^2) - (1/(n2)^2), with R = 3.29x10^15 Hz. After finding the frequency, you would use the c = λv to find wavelength. For b, you would look at the wavelength you got in part a and then look at th...
by Selena Yu 1H
Fri Oct 18, 2019 2:15 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals in relation to arrows
Replies: 10
Views: 89

Re: Orbitals in relation to arrows

The arrows that he draws in class is called the spin magnetic quantum number and they are telling us which way the electrons in the orbitals are spinning, which is either up and down. As for how you would determine whether or not the arrows are spinning up or down there will always be spin up and sp...
by Selena Yu 1H
Fri Oct 18, 2019 2:07 am
Forum: Properties of Light
Topic: Constants and equations
Replies: 4
Views: 27

Re: Constants and equations

No, we would be giving an equations and constants sheet. It should be the first page of the test.
by Selena Yu 1H
Fri Oct 18, 2019 2:06 am
Forum: *Particle in a Box
Topic: Particle in a box
Replies: 1
Views: 40

Re: Particle in a box

A particle in a box has zero potential energy inside the box because it has kinetic energy. Since, the particle is inside the box it's constantly moving around because it keep hitting the walls/sides of the box giving it kinetic energy and since it has kinetic energy it would have zero potential ene...
by Selena Yu 1H
Thu Oct 10, 2019 9:47 pm
Forum: Photoelectric Effect
Topic: Photons and electrons
Replies: 5
Views: 52

Photons and electrons

I was wondering how do you know the right wavelength to have the electrons ejected. How do we figure out the right wavelength? Is there an equation for that?
by Selena Yu 1H
Thu Oct 10, 2019 9:42 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect
Replies: 3
Views: 61

Photoelectric Effect

I'm still confused on the difference between the photoelectric effect and atomic spectra. I know that for both a higher frequency is better as there is more energy to eject the electron. So, what is the difference? Is it just the way the experiments are conducted?
by Selena Yu 1H
Thu Oct 10, 2019 9:38 pm
Forum: Einstein Equation
Topic: Energy of photons to Moles
Replies: 2
Views: 47

Re: Energy of photons to Moles

You would use the equations E=hv and c=λv to first find the energy of the photon and then you would multiply the energy of the photon by Avogadro's number.
by Selena Yu 1H
Thu Oct 10, 2019 3:20 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactant Problem
Replies: 2
Views: 55

Re: Limiting Reactant Problem

For part a, you would first find the the limiting reactant of the first equation. You will find out that P4 is limiting and then you would use the moles of P4 to find the limiting reactant between O2 or P4O6. The limiting reactant is O2 Then for part b, you would use the moles of the O2 found from t...
by Selena Yu 1H
Thu Oct 10, 2019 3:09 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: # of molecules and formula units?
Replies: 5
Views: 87

Re: # of molecules and formula units?

Yes, you would use Avogadro's number to find both the number of molecules or formula units
by Selena Yu 1H
Thu Oct 03, 2019 10:05 pm
Forum: Properties of Light
Topic: Spectroscopy
Replies: 3
Views: 41

Spectroscopy

How can light be absorbed by an electron?
by Selena Yu 1H
Thu Oct 03, 2019 10:02 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: E. Moles and Molar Masses
Replies: 2
Views: 26

Re: E. Moles and Molar Masses

First, you would want to figure out what the metal is in M (OH)2. The molar mass of (OH)2 is 34.016 g/mol. You know the molar mass for M (OH)2, which is 74.10 g/mol. Therefore to figure out the molar mass of the metal (M), you would subtract 34.016 g/mol from 74.10 g/mol. You would get 40.084 g/mol ...
by Selena Yu 1H
Thu Oct 03, 2019 9:49 pm
Forum: Balancing Chemical Reactions
Topic: Combining Atoms
Replies: 1
Views: 36

Re: Combining Atoms

You look at the periodic table and you look at their charges to determine how many atoms you need to balance out those positive and negative charges for ionic compounds. For example, aluminum has a 3+ charge and chloride has a 1- charge. So in order to balance out the charges, chloride would need 3 ...
by Selena Yu 1H
Thu Oct 03, 2019 9:43 pm
Forum: Molarity, Solutions, Dilutions
Topic: textbook problem G.25
Replies: 3
Views: 44

Re: textbook problem G.25

We went over this in my discussion section today and our TA agreed that this was a tricky problem. So what you first do is: 10 ml x 1L/1000ml = 0.01L x 0.10mol/L = 0.001 mol x Avogadro's number/1mol = 6.0 x10^20 molecules of X 6.0 x10^20 molecules x (1/2)^n = 1 molecule And then you solve for n. If ...
by Selena Yu 1H
Thu Oct 03, 2019 9:33 pm
Forum: SI Units, Unit Conversions
Topic: How many Sig Figs are necessary?
Replies: 4
Views: 65

Re: How many Sig Figs are necessary?

You would put a 0 after 5 so it would be 0.0012950 because the two zeros in front of the one doesn't count as sig figs. Hope this helps!
by Selena Yu 1H
Thu Oct 03, 2019 9:24 pm
Forum: Empirical & Molecular Formulas
Topic: Test Materials
Replies: 13
Views: 117

Re: Test Materials

No, I don't think we are required to know the common polyatomic ions. I'm pretty sure that they'll give us the names of any molecules. All we need to know is the stuff we covered in class like limiting reactants, combustion problems, balancing equations, and dilution problems.

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