Search found 55 matches

by Jared Khoo 1G
Sat Dec 07, 2019 12:53 pm
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 3762

Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]

Lauren Haight 1E wrote:for mini marshmallow 2b, why is the coordination number for Dihydroxoyoxolatocobalt (III) 4?


Oxalate is BIdentate, so it will form 2 coordinate covalent bonds. Add this to the two bonds made to hydroxide and the coordination number is 4.
by Jared Khoo 1G
Sat Dec 07, 2019 12:52 pm
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 3762

Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]

Joanne Kang 3I wrote:min marshmallows 1c... why isn't it neutral?


ammonium is a conjugate acid of a weak base, so it will lower pH by giving a proton (H+) to water to form hydronium.
by Jared Khoo 1G
Sat Dec 07, 2019 12:51 pm
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 3762

Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]

For mini marshmallows 2c, why is it cupperate instead of copper? Isn't it a +1 oxidation state? The coordination complex has a 1- charge, so it is cuprate. This is shown because it forms an ionic bond with potassium which has a +1 charge, so you know the coordination complex must have a -1 charge. ...
by Jared Khoo 1G
Thu Dec 05, 2019 2:44 pm
Forum: Identifying Acidic & Basic Salts
Topic: HW 6D.11 e and f
Replies: 1
Views: 18

Re: HW 6D.11 e and f

For e, Al has a strong charge (+3) so it can take away protons. Remember that small highly charged metals act as acids. As Cl - is a conjugate base of a strong acid, it does not affect pH. For f, Cu again is a metal that has a strong charge (+2, which is kind of borderline). I think that Copper can ...
by Jared Khoo 1G
Thu Dec 05, 2019 2:35 pm
Forum: Quantum Numbers and The H-Atom
Topic: Midterm question with Rydberg
Replies: 1
Views: 30

Re: Midterm question with Rydberg

I'm kind of lost so I'll just walk through the problem. Ok to start we have 1.94 *10 -18 J for the change in energy by converting 102.557 nm to Energy which you have done. Then this value is equivalent to E final - E initial . However, as you are subtracting a negative (the E initial ), it becomes E...
by Jared Khoo 1G
Thu Dec 05, 2019 2:23 pm
Forum: Einstein Equation
Topic: units for energy
Replies: 2
Views: 20

Re: units for energy

The unit for energy is Joules, which is equivalent to a Newton*meter. Planck's constant h is in the units of m 2 kgs -1 and the unit for v frequency v is s -1 . Multiplying these together you would get m 2 kgs -2 . As a newton is in the units of kgms -2 , you can see that this equation indeed does f...
by Jared Khoo 1G
Thu Dec 05, 2019 2:18 pm
Forum: Naming
Topic: 9C 1C
Replies: 2
Views: 14

Re: 9C 1C

It is a negative ion, so you must add -ate to the end of the transition metal name. For reference Dr. Lavelle has the naming guide and it should be there.
by Jared Khoo 1G
Fri Nov 29, 2019 9:54 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2 Grades
Replies: 10
Views: 73

Re: Test 2 Grades

I think if you haven't gotten them already you will get them next week in discussion.
by Jared Khoo 1G
Fri Nov 29, 2019 9:53 pm
Forum: General Science Questions
Topic: hydrogen vs hydronium
Replies: 5
Views: 36

Re: hydrogen vs hydronium

Technically it is the concentration of Hydronium as the H+ will attach to a water molecule. However, it is easier to write H+ concentration which is why it is common.
by Jared Khoo 1G
Fri Nov 29, 2019 9:51 pm
Forum: SI Units, Unit Conversions
Topic: midterm/final
Replies: 18
Views: 184

Re: midterm/final

I think there will be a good balance between the two as it should probably follow the format of the midterms.
by Jared Khoo 1G
Fri Nov 29, 2019 9:50 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pH scale
Replies: 4
Views: 15

Re: pH scale

Most of the substances that we will work with, if not all, will have pH values between 0 and 14 corresponding to Hydronium ion concentrations that range from 1 * 100 M*L-1 to 1* 10-14 M*L-1
by Jared Khoo 1G
Fri Nov 29, 2019 9:47 pm
Forum: Biological Examples
Topic: cisplatin
Replies: 6
Views: 38

Re: cisplatin

Does anyone remember what specific nucleotide Cisplatin attaches to?
by Jared Khoo 1G
Wed Nov 20, 2019 9:00 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7726
Views: 1044514

Re: Post All Chemistry Jokes Here

Why is working with ammonia easy?
Because its quite basic.
by Jared Khoo 1G
Wed Nov 20, 2019 8:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 5
Views: 61

Re: Test 2

I believe it goes up to 2F.1.
by Jared Khoo 1G
Wed Nov 20, 2019 8:55 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7726
Views: 1044514

Re: Post All Chemistry Jokes Here

Thank you Dr. Lavelle for putting the Cation in education.
by Jared Khoo 1G
Wed Nov 20, 2019 8:54 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7726
Views: 1044514

Re: Post All Chemistry Jokes Here

How often do I tell chemistry jokes?
Periodically.
by Jared Khoo 1G
Wed Nov 20, 2019 8:52 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2 related HW problems
Replies: 2
Views: 52

Re: Test 2 related HW problems

Aman Sankineni 3E wrote:The questions on the syllabus from 3F, 2E, and anything that covers sigma and pi bonds, so 2F.1 will cover topics on the test.

Thank you.
by Jared Khoo 1G
Wed Nov 20, 2019 8:50 pm
Forum: Administrative Questions and Class Announcements
Topic: Test #2
Replies: 22
Views: 222

Re: Test #2

Probably up to "Explain how hybridization arises from atomic orbitals"
by Jared Khoo 1G
Wed Nov 13, 2019 6:04 pm
Forum: Dipole Moments
Topic: Hydrogen bonds
Replies: 17
Views: 78

Re: Hydrogen bonds

Just with N, O, or F.
by Jared Khoo 1G
Wed Nov 13, 2019 6:02 pm
Forum: Dipole Moments
Topic: Textbook question 3F.1
Replies: 5
Views: 36

Re: Textbook question 3F.1

All molecules have London Dispersion forces.
Molecules with uneven sharing of electrons (think polar/non-polar) will have dipole-dipole.
Molecules with Hydrogen bonded to a N, O, or F will have Hydrogen bonding.
by Jared Khoo 1G
Wed Nov 13, 2019 6:01 pm
Forum: Dipole Moments
Topic: HW Question 3F1
Replies: 5
Views: 34

Re: HW Question 3F1

SO2 is polar, hence the dipole-dipole interactions.
by Jared Khoo 1G
Wed Nov 13, 2019 5:59 pm
Forum: Dipole Moments
Topic: 3F.3
Replies: 5
Views: 40

Re: 3F.3

As CH4 and CCl4 are symmetrical (and tetrahedral) they are nonpolar and dipole dipole interactions will not be that important. However, they still have London dispersion forces despite being nonpolar.
by Jared Khoo 1G
Wed Nov 13, 2019 5:57 pm
Forum: Dipole Moments
Topic: How does O3 have dipole-dipole interactions?
Replies: 2
Views: 21

Re: How does O3 have dipole-dipole interactions?

Ozone is polar as it is bent, therefore it has a net dipole.
by Jared Khoo 1G
Wed Nov 13, 2019 5:55 pm
Forum: Dipole Moments
Topic: 3F.5
Replies: 6
Views: 51

Re: 3F.5

To finish off this problem,

C. CHI3 will have a higher melting point because iodine is bigger than chlorine with more electrons and therefore higher IMFs.
D. Methanol will have a higher melting point because of the presence of Hydrogen bonds.
by Jared Khoo 1G
Wed Nov 13, 2019 5:53 pm
Forum: Dipole Moments
Topic: 3F.5
Replies: 6
Views: 51

Re: 3F.5

Amy Luu 3I wrote:How do you determine that buthanol has h-bonds? How come diethyl ether doesn't have h bonds?

H bonds form when H is bonded to N, O or F.
by Jared Khoo 1G
Wed Nov 13, 2019 5:52 pm
Forum: Dipole Moments
Topic: 3F.5
Replies: 6
Views: 51

Re: 3F.5

Yeah, doesn't ether also have H bonds? They're bonded to the carbon just as in Butanol, so what's the difference? Is it because unlike in Ether, theres a carbon bonded to an Oxygen? If so, why is this important?? I don't think so because the Hydrogen is not bonded to N, O, or F, therefore there are...
by Jared Khoo 1G
Wed Nov 06, 2019 3:21 pm
Forum: *Shrodinger Equation
Topic: Explanation of Shrodinger Equation and Hamiltonian
Replies: 3
Views: 55

Re: Explanation of Shrodinger Equation and Hamiltonian

Victor James 4I wrote:how does this relate to orbitals?

I believe that valid solutions of Schrodinger's equation, psi, correspond to orbitals.
by Jared Khoo 1G
Wed Nov 06, 2019 3:18 pm
Forum: Administrative Questions and Class Announcements
Topic: DINO NUGGETS Review Session! Download Problems HERE [ENDORSED]
Replies: 52
Views: 3887

Re: DINO NUGGETS Review Session! Download Problems HERE [ENDORSED]

ayushibanerjee06 wrote:For 6b., I am confused about why GarBreadium has the longer deBroglie wavelength. Shouldn't it be He because it weighs more?

As mass is on the denominator for deBroglie wavelength calculations, a lower mass atom will have a longer wavelength as it is inversely proportional.
by Jared Khoo 1G
Thu Oct 31, 2019 5:56 pm
Forum: Student Social/Study Group
Topic: Midterm
Replies: 7
Views: 50

Re: Midterm

I believe he said in class it will include up to Focus 2D.
by Jared Khoo 1G
Thu Oct 31, 2019 5:55 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7726
Views: 1044514

Re: Post All Chemistry Jokes Here

OMG did you hear Oxygen and Magnesium were a couple?
by Jared Khoo 1G
Thu Oct 31, 2019 5:53 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7726
Views: 1044514

Re: Post All Chemistry Jokes Here

Don't throw sodium chloride around. It's a salt.
by Jared Khoo 1G
Thu Oct 31, 2019 5:49 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7726
Views: 1044514

Re: Post All Chemistry Jokes Here

Me: Hey Siri, can you give me the formula for Nitric Acid?
Siri: NO
Me: ...
by Jared Khoo 1G
Wed Oct 30, 2019 9:37 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm
Replies: 16
Views: 87

Re: Midterm

Fundamentals, Quantum World, and Chemical Bonds up to Section 2D
by Jared Khoo 1G
Wed Oct 23, 2019 11:32 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: how to do 1.D.23?
Replies: 2
Views: 26

Re: how to do 1.D.23?

I think you may have looked at the answer key incorrectly, mine says the right answer. Anyways, the thing that really matters is the l value, as it determines the orientation of the different orbitals. An l of 1 corresponds to a p orbital, which can be oriented 3 ways. When the m l is given, then th...
by Jared Khoo 1G
Wed Oct 23, 2019 11:29 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: What's the difference between subshell vs orbitals?
Replies: 8
Views: 58

Re: What's the difference between subshell vs orbitals?

Hopefully this helps. Also there is a chemistry stackexchange post on this topic with helpful images. If electrons share the value n, it is part of a shell. If electrons share n and l, it is part of the same sub-shell. If electrons share n, l and ml then it is in the same orbital. https://chemistry....
by Jared Khoo 1G
Wed Oct 23, 2019 11:27 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: l values
Replies: 4
Views: 45

Re: l values

l can go up to n-1, but in this class, we are only required to know up to the f orbital. Most likely we won't even see f orbitals as it doesn't really apply to living systems.
by Jared Khoo 1G
Wed Oct 23, 2019 11:26 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: order
Replies: 3
Views: 23

Re: order

With some exceptions where the s orbital is lower energy, since the d orbital is in a different shell you order that first. Eg. 4d then 5s.
by Jared Khoo 1G
Wed Oct 23, 2019 11:24 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: subshell or orbital?
Replies: 3
Views: 42

Re: subshell or orbital?

If electrons share the value n, it is part of a shell.
If electrons share n and l, it is part of the same sub-shell.
If electrons share n, l and ml then it is in the same orbital.
by Jared Khoo 1G
Sat Oct 19, 2019 9:25 pm
Forum: Properties of Light
Topic: light
Replies: 5
Views: 48

Re: light

Yes theoretically speaking there is nothing that can exceed the speed of light so if you calculate the velocity of an election exceeding the speed of light that is not possible.
by Jared Khoo 1G
Wed Oct 16, 2019 5:26 pm
Forum: Properties of Light
Topic: Constant for Speed of Light
Replies: 14
Views: 72

Re: Constant for Speed of Light

Given he provides 2.99792 × 10^8 m/s on the formula sheet pdf, I would use that, although I'm sure he would specify/be fine with either on homework.
by Jared Khoo 1G
Mon Oct 14, 2019 9:42 pm
Forum: Einstein Equation
Topic: Lecture Question!
Replies: 5
Views: 76

Re: Lecture Question!

I don't believe so, which is why there are discrete absorption/emission line spectra for each element. If an element were to absorb all frequencies and therefore all energies of light, then there would be no black spots in the emission spectrum. If you google hydrogen emission spectrum you'll see on...
by Jared Khoo 1G
Mon Oct 14, 2019 9:39 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 2321

Re: Test 1 [ENDORSED]

DesireBrown3K wrote:If someone was able to complete the Angstrom question, can you please explain to me (step by step) how to solve the problem?

An angstrom is 10-10m, so there are .1 angstrom in a nanometer and 100 angstroms in a picometer.
by Jared Khoo 1G
Mon Oct 14, 2019 9:37 pm
Forum: Einstein Equation
Topic: 1B.7 Part c
Replies: 3
Views: 38

Re: 1B.7 Part c

As you are given 1 mol of photons, and the energy per photon is calculated in part A, you take the energy (part A) in J/photon multiplied by 6.022 photons/mol which would yield the units J/mol, which is what the answer is looking for. You multiply this my 1 mol, and get the answer.
by Jared Khoo 1G
Mon Oct 14, 2019 8:10 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg indeterminacy equation
Replies: 2
Views: 24

Heisenberg indeterminacy equation

In class, we learned it as Delta P* Delta X >= h/4pi, but in the solutions manual it states that it is greater than or equal to (1/2)h. Can someone please clarify which one is the correct formula? Thanks.
by Jared Khoo 1G
Thu Oct 10, 2019 4:23 pm
Forum: Properties of Electrons
Topic: Planck's Constant
Replies: 3
Views: 45

Re: Planck's Constant

Planck's constant relates the energy in one photon of electromagnetic radiation to the frequency of that radiation. m2*kg/s is the same as Joule*second, as a joule is a kg *m2*s-2, so this multiplied by frequency in Hz (or s-1) would yield energy.
by Jared Khoo 1G
Thu Oct 10, 2019 4:18 pm
Forum: Properties of Light
Topic: HW 1B9
Replies: 2
Views: 35

Re: HW 1B9

You would want to take 32W * 2 seconds and divide it by your result from the energy released by each photon. You then should take the photons you have and divide by 6.022 *10^23 photons/mol, leaving you with moles of photons.
by Jared Khoo 1G
Thu Oct 10, 2019 4:15 pm
Forum: Properties of Electrons
Topic: Understanding Balmer & Lyman Series
Replies: 3
Views: 38

Re: Understanding Balmer & Lyman Series

As Romina said, the Lyman series refers to UV light, which has more energy than the visible light spectrum which is why it corresponds to going from n=1 to n=3, for example. The further away an electron is from the nucleus, less energy is required to jump to the next level, so lower energy light wil...
by Jared Khoo 1G
Wed Oct 09, 2019 10:53 pm
Forum: Photoelectric Effect
Topic: Kinetic Energy from the Photoelectric Effect
Replies: 5
Views: 48

Re: Kinetic Energy from the Photoelectric Effect

The excess energy becomes the kinetic energy of the electron that was ejected.
by Jared Khoo 1G
Wed Oct 09, 2019 1:44 pm
Forum: SI Units, Unit Conversions
Topic: Sig Fig Help! [ENDORSED]
Replies: 6
Views: 71

Re: Sig Fig Help! [ENDORSED]

Something that may be helpful is to write it in scientific notation as .0003 would be 3 * 10-4 which you can see is 1 significant figure, compared to something like 1.0003 * 100 which is 5.
by Jared Khoo 1G
Wed Oct 02, 2019 4:30 pm
Forum: Significant Figures
Topic: Lecture on Sig Figs?
Replies: 4
Views: 42

Re: Lecture on Sig Figs?

I don't think so as in the textbook sig figs are bunched together with accuracy and precision, so I don't think that he will cover it. Youtube videos and his page on sig figs help.
by Jared Khoo 1G
Wed Oct 02, 2019 4:24 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molar Mass
Replies: 5
Views: 50

Re: Molar Mass

Yes the calculation is the same as the difference is on the scale of 10-4 amu, the weight of an electron. Therefore the change in mass is not that much and is about the same.
by Jared Khoo 1G
Wed Oct 02, 2019 4:20 pm
Forum: Significant Figures
Topic: E21b. Sig Figs
Replies: 5
Views: 53

Re: E21b. Sig Figs

This was also confusing, but it may be possible that when calculating the molar mass of HF, you use 1.01 as the molar mass for hydrogen which is given in 3 significant figures so the book would like to keep using 3 significant figures.
by Jared Khoo 1G
Wed Oct 02, 2019 4:15 pm
Forum: Molarity, Solutions, Dilutions
Topic: G7)
Replies: 2
Views: 25

Re: G7)

Yes, the components would be water and the compound that is being diluted.
by Jared Khoo 1G
Tue Oct 01, 2019 11:35 pm
Forum: Empirical & Molecular Formulas
Topic: Empirical and Molecular Formulas [ENDORSED]
Replies: 5
Views: 63

Re: Empirical and Molecular Formulas [ENDORSED]

From the textbook, the empirical formula shows the relative number of atoms of each element in a compound by using the simplest whole-number subscripts. If you cannot simplify a molecular formula further, then it is also the empirical formula. An example is methane, which has both molecular formula ...

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