Search found 50 matches

by Michelle Chan 1J
Sun Dec 08, 2019 10:09 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 17
Views: 275

Re: Cisplatin

It is more effective than transplatin because it binds twice instead of once making it more effective.
by Michelle Chan 1J
Sun Dec 08, 2019 10:02 pm
Forum: Administrative Questions and Class Announcements
Topic: FINAL
Replies: 7
Views: 160

Re: FINAL

I thought it was pretty difficult compared to the questions we practiced :(.
by Michelle Chan 1J
Sun Dec 08, 2019 10:01 pm
Forum: Hybridization
Topic: 2sp2 and sp2
Replies: 10
Views: 145

Re: 2sp2 and sp2

I think you only need to write 2 if the questions asks for it specifically.
by Michelle Chan 1J
Sun Dec 08, 2019 10:00 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: -ido vs -o
Replies: 5
Views: 149

Re: -ido vs -o

-ido is the most updated IUPAC naming, but either works.
by Michelle Chan 1J
Fri Dec 06, 2019 12:42 pm
Forum: Biological Examples
Topic: EDTA
Replies: 1
Views: 38

Re: EDTA

EDTA prevents enzymatic activity, is hexadentate, and removes metals from solutions.
by Michelle Chan 1J
Thu Dec 05, 2019 1:53 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate compounds
Replies: 1
Views: 46

Re: Polydentate compounds

I think a single lone pair can be counted because in lecture, he used the example NH3 with only one lone pair.
by Michelle Chan 1J
Thu Dec 05, 2019 1:51 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: chelate
Replies: 3
Views: 51

Re: chelate

A ligand chelates when when it forms a ring including the central atom. It must be polydentate.
by Michelle Chan 1J
Thu Dec 05, 2019 1:49 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Weak vs Strong acids and bases
Replies: 6
Views: 60

Re: Weak vs Strong acids and bases

A strong base would have a higher pH because it accepts more protons.
by Michelle Chan 1J
Thu Dec 05, 2019 1:47 pm
Forum: Biological Examples
Topic: Biological questions on the final
Replies: 5
Views: 98

Re: Biological questions on the final

I would know the examples that he explained during lecture, such as hemoglobin.
by Michelle Chan 1J
Thu Dec 05, 2019 1:45 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: -ate
Replies: 11
Views: 206

Re: -ate

Add -ate to the end of the metal name if the complex is negative
by Michelle Chan 1J
Fri Nov 22, 2019 5:43 pm
Forum: Lewis Acids & Bases
Topic: Lewis & Bronsted
Replies: 3
Views: 42

Re: Lewis & Bronsted

Same concept, just named after different people/theories.
by Michelle Chan 1J
Fri Nov 22, 2019 5:42 pm
Forum: Coordinate Covalent Bonds
Topic: Coordinate vs polar covalent
Replies: 6
Views: 177

Re: Coordinate vs polar covalent

For the post above, a bronsted acid is a proton donor and a lewis acid in an e- acceptor.
by Michelle Chan 1J
Fri Nov 22, 2019 5:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: T-shaped v. Trigonal pyramid
Replies: 9
Views: 99

Re: T-shaped v. Trigonal pyramid

Yes, that is correct!
by Michelle Chan 1J
Mon Nov 18, 2019 12:59 pm
Forum: Student Social/Study Group
Topic: Test 2
Replies: 5
Views: 73

Re: Test 2

Shapes, polarity, and sigma/pi bonds will be on the test. So up to Monday's first slide!
by Michelle Chan 1J
Mon Nov 18, 2019 12:56 pm
Forum: Bond Lengths & Energies
Topic: Curve
Replies: 4
Views: 141

Re: Curve

I don't think the midterm grades itself are curved. Only the class at the end.
by Michelle Chan 1J
Fri Nov 15, 2019 11:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: regions of electron density
Replies: 7
Views: 62

Re: regions of electron density

lone pair, bond, or radical
by Michelle Chan 1J
Fri Nov 15, 2019 11:37 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 9
Views: 209

Re: Formal Charge

A side question: is there a way to tell just by looking because some people derive it really quickly in their head. Just wondering.
by Michelle Chan 1J
Fri Nov 15, 2019 11:35 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: Test Topics
Replies: 11
Views: 147

Re: Test Topics

In class he said everything up to sigma and pi bonds (which we will learn on Monday), so IMF, shapes, and bonds.
by Michelle Chan 1J
Fri Nov 15, 2019 11:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Determining if a molecule is polar or non polar
Replies: 9
Views: 87

Re: Determining if a molecule is polar or non polar

I don't think we need to know exact values, but we should know generally which atom is the most electronegative in relation to others in the molecule.
by Michelle Chan 1J
Thu Nov 14, 2019 4:00 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: why are double bonds equally weighted as single ones when drawing models?
Replies: 10
Views: 99

Re: why are double bonds equally weighted as single ones when drawing models?

I am not completely sure, but yes they are only counted as one. Maybe because e- are so light that it is insignificant.
by Michelle Chan 1J
Thu Nov 07, 2019 11:08 am
Forum: Trends in The Periodic Table
Topic: Midterm Review Problem 10 d
Replies: 5
Views: 143

Re: Midterm Review Problem 10 d

If you draw out the three orbitals, N is more stable because they are each filled with one e-, thus O would want to lose one to become more stable.
by Michelle Chan 1J
Thu Nov 07, 2019 11:06 am
Forum: Photoelectric Effect
Topic: Midterm 1
Replies: 9
Views: 272

Re: Midterm 1

I also struggled with this. I was thinking it has something to do with Avogadro's number? I'm not completely sure.
by Michelle Chan 1J
Thu Nov 07, 2019 11:04 am
Forum: Student Social/Study Group
Topic: Class Grading
Replies: 44
Views: 1706

Re: Class Grading

How exactly does this work? So is the class curved in the end?
by Michelle Chan 1J
Thu Nov 07, 2019 10:58 am
Forum: Photoelectric Effect
Topic: Maximum Wavelength
Replies: 2
Views: 112

Re: Maximum Wavelength

I agree with the answer above, but shorter wavelengths have more energy so I'm assuming by "maximum wavelength" they mean the longest and least energy wavelength it would take to eject an electron.
by Michelle Chan 1J
Thu Nov 07, 2019 10:52 am
Forum: Lewis Structures
Topic: Does the shape that I draw the Lewis structure matter?
Replies: 14
Views: 111

Re: Does the shape that I draw the Lewis structure matter?

Not for now, but we probably will have to take it into account when we learn about different shapes later!
by Michelle Chan 1J
Sun Nov 03, 2019 10:16 am
Forum: Electronegativity
Topic: electronegativity trend
Replies: 9
Views: 77

Re: electronegativity trend

The distance between the nucleus and the electrons increase, therefore decreasing the attraction for e-.
by Michelle Chan 1J
Fri Nov 01, 2019 11:37 am
Forum: Ionic & Covalent Bonds
Topic: How does one find a most likely charge for ions for a given element?
Replies: 6
Views: 86

Re: How does one find a most likely charge for ions for a given element?

The atom would lose its unpaired electrons to become an ion or gain e- to fill its shell. For example, H would lose 1 e- to become H+1 and F would gain an e- to fill its shell to come F-1.
by Michelle Chan 1J
Thu Oct 31, 2019 5:05 pm
Forum: Bond Lengths & Energies
Topic: Bond energies
Replies: 4
Views: 47

Re: Bond energies

I am not entirely sure in which context you are asking, but triple > double > single bonds in decreasing order.
by Michelle Chan 1J
Wed Oct 30, 2019 9:30 pm
Forum: Ionic & Covalent Bonds
Topic: Radicals
Replies: 9
Views: 83

Re: Radicals

For example, CH3 is a radical because there is an unpaired electron. Food supplements, such as vitamins, can react with radicals before they cause damage.
by Michelle Chan 1J
Wed Oct 30, 2019 9:26 pm
Forum: Electronegativity
Topic: Electronegativity vs. Electron Affinity
Replies: 7
Views: 79

Re: Electronegativity vs. Electron Affinity

Electronegativity is how "greedy" atoms are for e-. So atoms with 7 valence e- are more electronegative than atoms with 8e-. Electron affinity is the amount of energy released when an electron is added to a neutral atom.
by Michelle Chan 1J
Sun Oct 27, 2019 11:51 pm
Forum: Student Social/Study Group
Topic: Study Tips
Replies: 58
Views: 1866

Re: Study Tips

I like the compile my notes into one big study guide on google docs and also do (redo) practice problems from the homework.
by Michelle Chan 1J
Thu Oct 24, 2019 4:33 pm
Forum: Properties of Electrons
Topic: hw
Replies: 6
Views: 94

Re: hw

I think we can because we were finishing up the chapter this week in lecture.
by Michelle Chan 1J
Thu Oct 24, 2019 4:06 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: HW 1E.23
Replies: 4
Views: 59

HW 1E.23

I am a little confused on how to figure out the number of unpaired electrons for question 1E.23. For example, how many unpaired e- would be in Ga or Ge? Can someone explain? Thanks!
by Michelle Chan 1J
Thu Oct 24, 2019 1:04 pm
Forum: Ionic & Covalent Bonds
Topic: strength of bonds
Replies: 11
Views: 265

Re: strength of bonds

Usually shorter bonds (in distance, Angstroms) are stronger than longer bonds.
by Michelle Chan 1J
Wed Oct 23, 2019 6:01 pm
Forum: Lewis Structures
Topic: chemical formulas
Replies: 3
Views: 59

Re: chemical formulas

I am not completely sure, but in the examples in class, they were given. For more commonly known compounds, we should be able to derive the chemical formula with the name.
by Michelle Chan 1J
Wed Oct 16, 2019 9:08 pm
Forum: Quantum Numbers and The H-Atom
Topic: Stern and Gerlach
Replies: 5
Views: 55

Re: Stern and Gerlach

I wrote down in my notes that this experiment discovered the electron spin. Silver atoms with one unpair e- split into two beam. Thus, e- can spin up or down, so we use quantum numbers ms=+1/2 and ms=-1/2.
by Michelle Chan 1J
Wed Oct 16, 2019 9:03 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: What does the "x" indicate in (i.e.) the 2px state? [ENDORSED]
Replies: 5
Views: 50

Re: What does the "x" indicate in (i.e.) the 2px state? [ENDORSED]

I think x,y, and z correlate to the planes. He derived x by looking at the table from the slides.
by Michelle Chan 1J
Wed Oct 16, 2019 4:23 pm
Forum: Trends in The Periodic Table
Topic: Atomic radii
Replies: 9
Views: 102

Re: Atomic radii

Since the number of protons is increasing as you go right on the periodic table, the the effective nuclear charge increases and the nuclear pull is greater, thus resulting in a smaller radii.
by Michelle Chan 1J
Wed Oct 16, 2019 3:31 pm
Forum: Photoelectric Effect
Topic: Particle vs. Wave Model
Replies: 5
Views: 68

Re: Particle vs. Wave Model

I think you are correct. Light is a wave because it demonstrates wave properties, but when considered as packets of photons, it own demonstrate particle-like properties. This is called wave-particle duality. It depends on the circumstances and what effects you're studying.
by Michelle Chan 1J
Wed Oct 16, 2019 2:56 pm
Forum: Quantum Numbers and The H-Atom
Topic: X Y and Z
Replies: 7
Views: 108

X Y and Z

I kind of have an idea of this, but can someone clarify how to determine the if an e- is in the X Y or Z plane? Thanks!
by Michelle Chan 1J
Fri Oct 11, 2019 7:00 pm
Forum: Limiting Reactant Calculations
Topic: Exercise M.1
Replies: 3
Views: 167

Re: Exercise M.1

You would have to use stoichiometry. Set up a dimensional analysis to find the grams of hydrazine given 35g of ammonia. The solution to your dimensional analysis is the expected yield. Divide 25.2g (actual) by your solution (expected), then multiply by 100 to get your percent yield.
by Michelle Chan 1J
Fri Oct 11, 2019 6:48 pm
Forum: Einstein Equation
Topic: E=hv
Replies: 8
Views: 114

Re: E=hv

I agree with the person above^. Also, if you ever forget, it's listed on top of the formula sheet we get during the test.
by Michelle Chan 1J
Fri Oct 11, 2019 4:36 pm
Forum: DeBroglie Equation
Topic: Applying the DeBroglie Equation
Replies: 6
Views: 56

Re: Applying the DeBroglie Equation

The De Broglie Equation is used for any particle with momentum and has wavelike properties with a wavelength. Remember to not use EM equations for electrons!
by Michelle Chan 1J
Fri Oct 11, 2019 4:34 pm
Forum: Empirical & Molecular Formulas
Topic: empirical = molecular?
Replies: 15
Views: 399

empirical = molecular?

If the molar mass of the empirical formula is the same as the one given in the question, is the molecular formula the same as the empirical? Or is there no molecular formula?
by Michelle Chan 1J
Thu Oct 10, 2019 4:36 pm
Forum: Empirical & Molecular Formulas
Topic: Homework F9
Replies: 4
Views: 81

Homework F9

For F9, I understand all the steps until you multiply to get the molecular formula. How do you know to multiply 3? Do you just keep multiplying until you get whole coefficients?
by Michelle Chan 1J
Thu Oct 03, 2019 10:40 pm
Forum: Properties of Light
Topic: Spectroscopy
Replies: 4
Views: 74

Re: Spectroscopy

Blue light has more energy because it has a shorter wavelength. Blue light has a higher frequency than red light.
by Michelle Chan 1J
Thu Oct 03, 2019 10:20 pm
Forum: Balancing Chemical Reactions
Topic: Diatomic elements?
Replies: 8
Views: 114

Re: Diatomic elements?

I think that's just how they naturally occur. For example, you won't find just one singular oxygen atom, thus we make them diatomic in chemical equations.
by Michelle Chan 1J
Thu Oct 03, 2019 11:56 am
Forum: Empirical & Molecular Formulas
Topic: Homework L39
Replies: 5
Views: 74

Re: Homework L39

The roman numeral in the parenthesis represent the charge since those metals have various charges. Since 02 is -4, tin must be +4 (IV).
by Michelle Chan 1J
Thu Oct 03, 2019 11:32 am
Forum: SI Units, Unit Conversions
Topic: Sig Fig Mistakes
Replies: 17
Views: 272

Re: Sig Fig Mistakes

I agree with the post above. I remember from high school chem there were certain sig figs rules. For example, when multiplying or dividing, you answer with the least number of sig figs in the problem. For addition and subtraction, the answer can not contain more decimal places than the least precise...
by Michelle Chan 1J
Wed Oct 02, 2019 5:35 pm
Forum: Molarity, Solutions, Dilutions
Topic: HW problem G21
Replies: 3
Views: 75

Re: HW problem G21

Molarity is moles/volume of solution. So to use (b) as an example, first I would find the moles of S ions in 0.500g of K2S with stoichiometry --> 0.500g K2S x 1 mol K2S/110.26g x 1 mol S/ 1 mol K2S. Then convert 500. mL of volume to 0.5 L. Finally, divide the number of moles by volume to get M. Hope...

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