Search found 23 matches

by John Kim Lec3Dis3L
Fri Dec 07, 2018 3:54 am
Forum: Amphoteric Compounds
Topic: Polydentate
Replies: 2
Views: 117

Re: Polydentate

What is a polydentate would it be just an anion that has more than 4 bonding sites? Can someone give an explanation and example? The textbook (6th edition) defines polydentate as "many-toothed", or able to attach at more than one bonding site simultaneously. Basically, this just means tha...
by John Kim Lec3Dis3L
Fri Dec 07, 2018 3:39 am
Forum: Lewis Acids & Bases
Topic: Determining which H^+ ions are given off
Replies: 4
Views: 152

Re: Determining which H^+ ions are given off

It depends on the molecule in question. If it's simple, like HNO3, you can be relatively sure of where the H^+ will come from. If the molecule is more complex, like CH3COOH, it might be necessary to draw a Lewis structure to see which hydrogen is farthest from the central atom; honestly though, it s...
by John Kim Lec3Dis3L
Fri Dec 07, 2018 3:33 am
Forum: Bronsted Acids & Bases
Topic: How to tell if it is an acid or base?
Replies: 4
Views: 259

Re: How to tell if it is an acid or base?

A general rule of thumb is to see whether the molecule predominantly contains (H^+) or (OH^-). Hope this helps!
by John Kim Lec3Dis3L
Thu Nov 29, 2018 2:02 pm
Forum: Biological Examples
Topic: acids
Replies: 5
Views: 199

Re: acids

Another reason that our digestive system can handle such liquids is due to its protective coating of mucus. That is the reason that our stomach can handle containing acid and the cause of stomach ulcers (the mucus in a spot decreases, allowing the acid to partially corrode the stomach lining).
by John Kim Lec3Dis3L
Thu Nov 29, 2018 1:58 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Number
Replies: 10
Views: 303

Re: Coordination Number

The coordination number is the number of ligands bonded to the central atoms. It seems that the coordination number can be found by just tallying the number of other atoms or other, smaller molecules within the complex's formula ( ex. coordination number 4 for [CoCl4]^(2-) or 2 for [HgCl2] ). Usual ...
by John Kim Lec3Dis3L
Thu Nov 29, 2018 1:42 pm
Forum: Naming
Topic: Common Ligand Names
Replies: 4
Views: 235

Re: Common Ligand Names

His outline for this unit says that we have to be familiar with the rules for naming, but it doesn't say that we have to we know the actual names.
by John Kim Lec3Dis3L
Fri Nov 09, 2018 2:53 am
Forum: Electronegativity
Topic: electronegativity trends
Replies: 6
Views: 246

Re: electronegativity trends

I think it's not so much that there is a causal relationship between electronegativity and electron shielding as a correlative relationship for these periodic trends.
by John Kim Lec3Dis3L
Fri Nov 09, 2018 2:51 am
Forum: Resonance Structures
Topic: homework question 3.71 (6th edition)
Replies: 3
Views: 160

Re: homework question 3.71 (6th edition)

To build on what the others have said, you basically need to search for the molecule whose individual formal charges average closest to zero; that molecule is going to be most likely to make the more dominant contribution.
by John Kim Lec3Dis3L
Fri Nov 09, 2018 2:47 am
Forum: Ionic & Covalent Bonds
Topic: Polarizability
Replies: 9
Views: 407

Re: Polarizability

Polarizability depends on the number of electrons present and on the size of the pertinent atom. Higher polarizability means that the atom or ion has a more readily distortable electron cloud; the process of distortion itself is known as polarization.
by John Kim Lec3Dis3L
Mon Nov 05, 2018 3:31 am
Forum: Administrative Questions and Class Announcements
Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
Replies: 121
Views: 7103

Re: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]

Can someone explain 1. to me? Thanks in advance! Step 1: Find the molar masses of CO2 and H2O Step 2: Calculate the moles of CO2 and H2O by dividing grams by moles Step 3: Find simplest ratio of two compounds' moles Step 4: Balance full chemical equation ( _ C?H?O? + _ O2 -> _ CO2 + _ H2O ) using a...
by John Kim Lec3Dis3L
Thu Nov 01, 2018 11:53 pm
Forum: Coordinate Covalent Bonds
Topic: Coordinate Covalent Bond Definition
Replies: 14
Views: 1087

Re: Coordinate Covalent Bond Definition

For all you 6th edition people out there who see this, the definition is on page 231, stated as "[a] bond in which both electrons come from one of the atoms".
by John Kim Lec3Dis3L
Thu Nov 01, 2018 11:49 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 8
Views: 336

Re: Formal Charge

Heidi Ibarra Castillo 1D wrote:How do you determine your V, L , and S?


Rules for determining FC from the notes from class:
1. Determine number of valence e- for each bound atom
2. Determine number of bonding electrons (S)
3. Determine number of lone e- pairs (L)
4. Determine number of valence e- for each free atom (V)
by John Kim Lec3Dis3L
Thu Nov 01, 2018 11:42 pm
Forum: Lewis Acids & Bases
Topic: Lewis Acids and Bases on Midterm
Replies: 4
Views: 262

Re: Lewis Acids and Bases on Midterm

I am in Lecture 3 and Dr. Lavelle said in class that everything up to Wednesday (yesterday) would be covered, which includes Lewis acids and bases. I doubt he really wants us to know a vast amount about them, though; it's probably ok to just know the fact that group 13 elements need 5 electrons to c...
by John Kim Lec3Dis3L
Sat Oct 20, 2018 1:09 am
Forum: Ionic & Covalent Bonds
Topic: Electron Configuration of Cations
Replies: 8
Views: 374

Re: Electron Configuration of Cations

Basically, the Roman numeral signifies the number of non-negated positive charges. Hence, copper (I) has a charge of +1 and copper (2) +2.
by John Kim Lec3Dis3L
Sat Oct 20, 2018 12:58 am
Forum: Ionic & Covalent Bonds
Topic: Electron Configuratin
Replies: 5
Views: 211

Re: Electron Configuratin

Just think of it like you can only start from the rightmost electrons on. This was actually touched upon in class: the inner sub-shells of electrons actually block the effects of the positively charged nucleus on outer sub-shells.
by John Kim Lec3Dis3L
Sat Oct 20, 2018 12:56 am
Forum: Lewis Structures
Topic: Central atom and octet rule?
Replies: 12
Views: 1206

Re: Central atom and octet rule?

is there a rule to know when some atoms are okay with having less than 8 electrons? or should we just memorize some of them and hope for the best? i think it is just memorization but its basically just group 13 and H, He, Li, Be This actually showed up in another post I think, and don't quote me on...
by John Kim Lec3Dis3L
Fri Oct 12, 2018 7:10 am
Forum: Quantum Numbers and The H-Atom
Topic: Balmer/Lyman... Series
Replies: 4
Views: 147

Re: Balmer/Lyman... Series

Just to add on a bit to the other answer, the textbook has practice questions that use more than just the Lyman and Balmer levels in terms of both names and level number; it would probably be for the best to memorize them.
by John Kim Lec3Dis3L
Fri Oct 12, 2018 7:06 am
Forum: Photoelectric Effect
Topic: How do I find the mass of an ejected electron?
Replies: 3
Views: 185

Re: How do I find the mass of an ejected electron?

As the other posters said, electrons do not change their mass. For this class, you can just use 9.10938E-31 kg as your mass; any more accuracy would probably be overkill for our level of academia.
by John Kim Lec3Dis3L
Fri Oct 12, 2018 7:03 am
Forum: Properties of Electrons
Topic: Electron Energy Levels
Replies: 2
Views: 149

Re: Electron Energy Levels

Why are electron energy levels quantized? Why can't electrons exist in between quantized electron energy levels? In response to your question, quantization just means that the electrons can only take integer values of discrete energy packets. Essentially, electrons separate into whole-number levels...
by John Kim Lec3Dis3L
Thu Oct 04, 2018 10:53 pm
Forum: Limiting Reactant Calculations
Topic: What is the mass of AgCl produced?
Replies: 10
Views: 4614

Re: What is the mass of AgCl produced?

After guessing a checking i found that the answer is 1.72 g AgCl. I found that the limiting reactant is C6H9Cl3 and that the moles of this compound is .004 moles. To get the answer 1.72, i saw that you have to triple .004 moles and then multiple that by the molar mass which is 143.32 g/mol. I am un...
by John Kim Lec3Dis3L
Wed Oct 03, 2018 8:59 pm
Forum: SI Units, Unit Conversions
Topic: Homework Questions [ENDORSED]
Replies: 14
Views: 573

Re: Homework Questions [ENDORSED]

I'm not completely sure, but the is how I see it: Basically, you're supposed to do problems for whatever the material covered in the week in question is/was. So if you cover information that would be part of multiple letter sections, then you're supposed to do problems from those sections.
by John Kim Lec3Dis3L
Wed Oct 03, 2018 8:57 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Mole Definition
Replies: 5
Views: 244

Re: Mole Definition

A mole is just like a dozen, but instead of signifying 12 of something, it signifies 6.022x10^23. The reason that this number is used is because 6.022x10^23 amu is equal to 1 gram. This helps make calculations simpler. Well, to add on to what this poster is saying, an AMU is a mass unit equal to 1/...
by John Kim Lec3Dis3L
Wed Oct 03, 2018 8:37 pm
Forum: SI Units, Unit Conversions
Topic: Converting between Temperatures (K,C,F)
Replies: 4
Views: 238

Re: Converting between Temperatures (K,C,F)

In response to the OP, there is essentially no way to go straight from Fahrenheit to Kelvin or vice versa without including the steps for Celsius.

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