Search found 72 matches
- Sat Dec 07, 2019 7:22 pm
- Forum: Bond Lengths & Energies
- Topic: Radicals
- Replies: 5
- Views: 486
Radicals
How do you rank radicals?
- Sat Dec 07, 2019 2:15 pm
- Forum: Lewis Acids & Bases
- Topic: Lewis acid
- Replies: 3
- Views: 368
Lewis acid
Why isn't NH4+ considered a Lewis acid?
- Sat Dec 07, 2019 1:47 am
- Forum: Air Pollution & Acid Rain
- Topic: Acid rain
- Replies: 2
- Views: 284
Acid rain
What exactly do we need to know about acid rain?
- Fri Dec 06, 2019 12:06 am
- Forum: Bronsted Acids & Bases
- Topic: Acidic Strength
- Replies: 3
- Views: 269
Acidic Strength
Why is HClO2 stronger than HBrO2 even though they have the same electronegativity and Br is bigger than Cl?
- Thu Dec 05, 2019 11:23 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: pKa
- Replies: 1
- Views: 152
pKa
What is pKa and what do we use it for?
- Thu Dec 05, 2019 9:04 pm
- Forum: Lewis Acids & Bases
- Topic: Lewis Acids/Bases vs Bronsted
- Replies: 1
- Views: 184
Lewis Acids/Bases vs Bronsted
I know the definitions of Lewis acids/bases and Bronsted acids/bases, but I'm having trouble being able to tell which on is which when looking at molecules. What should I look for in order to be able to differentiate the two?
- Thu Dec 05, 2019 6:59 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acid Strength
- Replies: 2
- Views: 168
Acid Strength
How can you tell an acid is stronger just by looking at its chemical formula?
- Thu Dec 05, 2019 6:58 pm
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: Base Strength
- Replies: 1
- Views: 263
Base Strength
How can you tell a base is stronger just by looking at its chemical formula?
- Thu Dec 05, 2019 4:24 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Lone Pairs in this Compound
- Replies: 2
- Views: 188
Lone Pairs in this Compound
In the compound HN(CH2CH2NH2)2, I know that there are two lone pairs since there are two NH2s, but where is the third lone pair found? In the textbook it says that this is a tridentate ligand.
- Wed Dec 04, 2019 3:12 am
- Forum: Resonance Structures
- Topic: Bond Lengths
- Replies: 1
- Views: 295
Bond Lengths
How come delocalized electrons still allow for bond lengths to be the same even though double bonds are technically shorter than single bonds.
- Wed Dec 04, 2019 3:10 am
- Forum: Resonance Structures
- Topic: Bond Lengths
- Replies: 1
- Views: 266
Bond Lengths
When are bond lengths the same or different?
- Sun Dec 01, 2019 9:34 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydentate
- Replies: 5
- Views: 338
Polydentate
How can you tell when a molecule is polydentate?
- Sun Dec 01, 2019 12:42 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Number
- Replies: 2
- Views: 220
Coordination Number
How do you determine coordination numbers? I know it should say through the ligand, but what if we aren't given a ligand? For example, how do we know that Cu+ can have a coordination number of 2 or 4?
- Sat Nov 30, 2019 11:32 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Shapes
- Replies: 3
- Views: 237
Shapes
How can you tell the difference between when a complex is going to be either tetrahedral or square planar?
- Sat Nov 30, 2019 11:30 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Chelating ligands [ENDORSED]
- Replies: 1
- Views: 126
Chelating ligands [ENDORSED]
In the example Dr. Lavelle gave in class, it made sense what a chelating ligand should look like, but how can you tell when it is a chelating ligand if there is no atom in the center of the ring?
- Sat Nov 30, 2019 11:19 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligands
- Replies: 1
- Views: 108
Ligands
Can somebody please dumb down what a ligand is? I have tried understanding it but it just doesn't make sense to me. Thank you <3
- Sat Nov 30, 2019 10:25 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Complexes
- Replies: 1
- Views: 150
Complexes
How do we know when a molecule is going to be a complex? Should we even be worried about them?
- Thu Nov 21, 2019 3:42 pm
- Forum: Sigma & Pi Bonds
- Topic: Pi bonding
- Replies: 3
- Views: 226
Re: Pi bonding
Because in biology, the form of a molecule is vital for its function. The fact that pi bonds don't allow for rotation locks the molecule into a certain shape at double and triple bonds which allow molecules to do its function. Also, the fact that pi bonds don't allow for rotation leads to cis and t...
- Thu Nov 21, 2019 3:40 pm
- Forum: Ionic & Covalent Bonds
- Topic: Bond Strengths
- Replies: 2
- Views: 235
Bond Strengths
Can somebody please give me a list of bond-type strengths from strongest to weakest?
- Thu Nov 21, 2019 3:13 pm
- Forum: Sigma & Pi Bonds
- Topic: Pi bonding
- Replies: 3
- Views: 226
Pi bonding
Why is is important that pi bonding does not allow rotation within the molecules?
- Thu Nov 21, 2019 3:12 pm
- Forum: Sigma & Pi Bonds
- Topic: Need to Know
- Replies: 3
- Views: 196
Need to Know
What are the most important things that I should know about sigma and pi bonding aside from the fact that pi bonding does not allow rotation?
- Thu Nov 21, 2019 4:29 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Periodic Trends
- Replies: 8
- Views: 656
Periodic Trends
What are the periodic trends for polarizability and polarizing power?
- Thu Nov 21, 2019 4:13 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Potential energy
- Replies: 3
- Views: 254
Potential energy
Can somebody please explain the parameters of intermolecular energy in E is proportional to (-alpha1alpha2/r^6)?
- Mon Nov 18, 2019 11:16 pm
- Forum: Bond Lengths & Energies
- Topic: Hydrogen Bonding
- Replies: 13
- Views: 1037
Hydrogen Bonding
Can someone please explain where hydrogen bonding occurs? For example, if hydrogen is in the middle of a molecule, can hydrogen bonding still occur or does it have to be on the outer part of the molecule?
- Mon Nov 18, 2019 10:45 pm
- Forum: Ionic & Covalent Bonds
- Topic: Study Group
- Replies: 8
- Views: 476
Re: Study Group
Cynthia Gong 1L wrote:I'm interested in joining this group too! Where do you guys meet?
We're in Rieber Fireside right now :)
- Mon Nov 18, 2019 10:44 pm
- Forum: Dipole Moments
- Topic: Cancelling Dipole Moments
- Replies: 4
- Views: 352
Cancelling Dipole Moments
Can somebody please explain to me when dipole moments cancel out? Is it only when the surrounding atoms are all the same and the moment is going away from the central atom? For example, I thought CH2Cl2 would cancel dipole moments since Cl has two atoms pulling away from the central atom, but turns ...
- Mon Nov 18, 2019 9:46 pm
- Forum: Hybridization
- Topic: Test 2
- Replies: 6
- Views: 366
Test 2
Is hybridization going to be on Test 2? Dr. Lavelle stopped us at sig and pi bonds but on the syllabus it says that we need to know them. I'm just asking for clarification. Thank you so much!
- Sun Nov 17, 2019 11:29 pm
- Forum: Ionic & Covalent Bonds
- Topic: Study Group
- Replies: 8
- Views: 476
Re: Study Group
Drake Choi_1I wrote:Ok I'll see if my schedule lines up at all!
Sweet! I'll send you an email with my number and just lmk if it works out!
- Sun Nov 17, 2019 11:20 pm
- Forum: Ionic & Covalent Bonds
- Topic: Study Group
- Replies: 8
- Views: 476
Re: Study Group
Drake Choi_1I wrote:What days are you planning to study?
Honestly every single day leading up to Test 2!! Most likely after 9 pm because we have work/mandatory commitments. And we're trying to keep this study group leading up to the final too.
- Sun Nov 17, 2019 11:14 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Study Group
- Replies: 1
- Views: 183
Study Group
Hey chem kings and queens. A friend and I are looking for people who can help us out in chemistry because we're struggling really bad and we're really trying to do well in this class. We would greatly appreciate it if we could form a study group ASAP. If you are able to help us out, please let me kn...
- Sun Nov 17, 2019 11:14 pm
- Forum: Ionic & Covalent Bonds
- Topic: Study Group
- Replies: 8
- Views: 476
Study Group
Hey chem kings and queens. A friend and I are looking for people who can help us out in chemistry because we're struggling really bad and we're really trying to do well in this class. We would greatly appreciate it if we could form a study group ASAP. If you are able to help us out, please let me kn...
- Sun Nov 17, 2019 11:13 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Study Group
- Replies: 2
- Views: 190
Study Group
Hey chem kings and queens. A friend and I are looking for people who can help us out in chemistry because we're struggling really bad and we're really trying to do well in this class. We would greatly appreciate it if we could form a study group ASAP. If you are able to help us out, please let me kn...
- Sat Nov 16, 2019 7:01 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Definition
- Replies: 2
- Views: 323
Definition
What exactly is polarizability and how are we supposed to apply it? Like, what is its purpose because I'm kind of confused?
- Sat Nov 16, 2019 6:57 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 5
- Views: 365
Bond Angles
How can you tell when a bond angle is going to get smaller or larger? Also, for example, if the angle gets smaller, how do you know it went from 120 degrees to 109.5? Is this just something I would have to memorize?
- Sat Nov 16, 2019 6:55 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pairs
- Replies: 6
- Views: 577
Lone Pairs
How is it that sometimes a molecule has 4 bonding regions (one of them being a lone pair) but the shape is not tetrahedral? In class my TA was showing up examples of identifying shapes and he would erase the lone pair, but I'm not sure why. Do lone pairs not really matter, just the actual bonds?
- Sat Nov 16, 2019 5:57 pm
- Forum: Resonance Structures
- Topic: Resonance Structures
- Replies: 1
- Views: 234
Resonance Structures
In the instance of carbon monoxide (CO), how is it that it has a triple bond connecting the two and a lone pair on each side when carbon only has 4 valence electrons and oxygen 6???? Are we able to just move electrons around like that or is there another reason? I know we learned about coordinate co...
- Sat Nov 16, 2019 5:51 pm
- Forum: Octet Exceptions
- Topic: Octet expansion
- Replies: 6
- Views: 532
Octet expansion
When do we know that an element has an octet expansion and what is the maximum amount of electrons that would be allowed? So far in the course it seems that the most is 10, but are there instances where it can be more?
- Sat Nov 16, 2019 5:50 pm
- Forum: Dipole Moments
- Topic: Polarity
- Replies: 7
- Views: 413
Polarity
Can somebody please explain to me why CCl4 is nonpolar even though the dipole moments do not cancel out?
- Sun Nov 10, 2019 4:23 pm
- Forum: Bond Lengths & Energies
- Topic: Bond strength
- Replies: 4
- Views: 248
Bond strength
Bond strength is determined by the bond number right? Like a double bond is stronger than a single bond? Or what determines the strength of bonds?
- Sun Nov 10, 2019 4:22 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Using the equation
- Replies: 2
- Views: 207
Using the equation
Can somebody please explain to me how we would use this equation? The example in the textbook makes sense but when I go to actually apply it it does not make sense at all. Like they'll give us the weight in grams but I'm not sure how that's relevant. Thank you!
- Sun Nov 10, 2019 4:20 pm
- Forum: Resonance Structures
- Topic: Resonance Structures
- Replies: 3
- Views: 128
Resonance Structures
Will there ever be a time where a molecule has an element that does not have a complete octet? Also, if you draw a resonance structure with an incomplete octet, is it still valid but just very unstable? What should a "correct" resonance structure look like?
- Sun Nov 10, 2019 4:17 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Graph of energy levels
- Replies: 1
- Views: 216
Graph of energy levels
What is the graph of an electron rising/falling in energy levels supposed to look like? You know how there was a similar question on the midterm? Can somebody explain the energy process to me and how we know this?
- Sun Nov 10, 2019 4:10 pm
- Forum: Empirical & Molecular Formulas
- Topic: Empirical formula
- Replies: 2
- Views: 200
Empirical formula
Hi how are you supposed to find the empirical formula if you are only given the masses of the reactants? There was a similar one on the Dino Nuggets packet as well as on the exam but I didn't know how to go about it methodically. All I did was find the molecular formula knowing that the two sides of...
- Sun Nov 10, 2019 4:06 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Energy Levels
- Replies: 4
- Views: 333
Energy Levels
Hi, so I'm super confused on how I'm supposed to find the energy level an electron rises to (or drops to). I know that we are supposed to use the formula that Dr. Lavelle gave us, but I'm not sure how to use it exactly. For example, if I'm trying to find the level a Hydrogen atom rises to, how would...
- Mon Nov 04, 2019 10:44 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Textbook E13
- Replies: 1
- Views: 276
Textbook E13
How do you find the percent composition of isotopes when only given the molar masses of the element and the molar masses of the isotopes that compose it?
- Sun Nov 03, 2019 12:36 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge
- Replies: 5
- Views: 330
Formal Charge
When is it necessary to calculate the formal charge? Is it just to see if something is an ion? Or what exactly is the purpose of calculating the formal charge?
- Sun Nov 03, 2019 12:31 am
- Forum: Electronegativity
- Topic: Ionization energy and electronegativity
- Replies: 8
- Views: 769
Ionization energy and electronegativity
What is the relationship between ionization energy and electronegativity? Are they like the same thing or what differentiates them? Also, what are the periodic trends associated with these terms again?
- Sun Nov 03, 2019 12:28 am
- Forum: Octet Exceptions
- Topic: radical
- Replies: 5
- Views: 423
Re: radical
Radicals are basically molecules that have at least one unpaired electron, making them less stable than other molecules that have, for example, a completed octet.
- Sun Nov 03, 2019 12:25 am
- Forum: Lewis Structures
- Topic: Exceptions to the octet rule
- Replies: 3
- Views: 128
Exceptions to the octet rule
Hi so I'm not sure exactly what it means when there are exceptions to the octet rule. Which elements are capable of doing this and what does this mean in terms of drawing a Lewis structure? Like, does an expanded octet mean that you could technically draw 10 electrons on the Lewis structure? Or does...
- Sun Nov 03, 2019 12:20 am
- Forum: Sigma & Pi Bonds
- Topic: Sigma and Pi Bonds
- Replies: 3
- Views: 228
Sigma and Pi Bonds
What is the difference between a sigma and a pi bond and what information will be most useful in preparing for the exam regarding these bonds? Thanks!
- Fri Oct 25, 2019 8:50 pm
- Forum: Photoelectric Effect
- Topic: Rydberg Formula
- Replies: 1
- Views: 170
Rydberg Formula
Can somebody please explain the logic behind the variation of the Rydberg formula that Dr. Lavelle wants us to use? He told us not to use the equation from the book and instead told us to use another one, but I don't understand how they are equivalent. Thank you :)
- Fri Oct 25, 2019 8:46 pm
- Forum: Lewis Structures
- Topic: Knowing bond types
- Replies: 2
- Views: 132
Knowing bond types
How can I tell whether a bond is going to be a single, double, or triple bond? I can usually tell when a bond is going to be a single, but sometimes when I think that a single bond makes sense, it has to be a double bond or something. Thank you :)
- Fri Oct 25, 2019 8:42 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations
- Replies: 2
- Views: 142
Electron Configurations
When writing the electron configurations, does 3p come before or after 4s? In a video I watched it said that 3d came after the 4s, but that doesn't make sequential sense to me and I was wondering if anyone could explain this to me? Also, in discussion my TA was saying something about the different e...
- Fri Oct 25, 2019 8:33 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge
- Replies: 4
- Views: 176
Formal Charge
I'm confused on what the formal charge is. Is that the number that's superscripted next to the symbol for example Cl ^-? Can somebody also please explain to me which numbers go where in the equation for solving the formal charge? I was especially confused on where the S came from because what made s...
- Tue Oct 22, 2019 10:42 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations
- Replies: 4
- Views: 196
Electron Configurations
Hi can somebody please explain to me how you know the order when writing an electron configuration? For example, 1s, 2s, 2p....Is there a trick to remember the order? Also, how do you know how many electrons will fit in that orbital? Let me know if I have to clarify any parts of the question. Thank ...
- Tue Oct 22, 2019 10:41 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations
- Replies: 13
- Views: 2935
Electron Configurations
Hi can somebody please explain to me how you know the order when writing an electron configuration? For example, 1s, 2s, 2p....Is there a trick to remember the order? Also, how do you know how many electrons will fit in that orbital? Let me know if I have to clarify any parts of the question. Thank ...
- Sat Oct 19, 2019 6:37 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Using the equation
- Replies: 1
- Views: 146
Using the equation
When do I know that I'm supposed to apply the Uncertainty equation? Like what is it for and what are some trigger words that should make me realize that this is the equation that I need to use in order to solve the question? Thank you so much :)
- Thu Oct 17, 2019 6:06 pm
- Forum: DeBroglie Equation
- Topic: SI Units
- Replies: 4
- Views: 187
SI Units
So since the wavelength in question 1B.23 is given in pm and we know that the constant for 1 amu is 1.67493x10^-27 kg, does that mean that before we do any calculations we have to convert them to meters and grams? Also, how would the cancellations of the units work for that? I know that velocity is ...
- Thu Oct 17, 2019 4:52 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbitals
- Replies: 2
- Views: 66
Orbitals
How do you find the number of orbitals when you are given a specific orbital like 4p or 3d? Or would it still be 3 and 5 respectively? Thank you :)
- Thu Oct 17, 2019 4:34 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Orbitals
- Replies: 2
- Views: 180
Orbitals
How can you tell the number of orbitals just based off of the value of l? (Text. 1D.11) Thank you :)
- Thu Oct 17, 2019 11:29 am
- Forum: Photoelectric Effect
- Topic: Calculating the number of photons [ENDORSED]
- Replies: 2
- Views: 699
Calculating the number of photons [ENDORSED]
How do you calculate the number of photons as described in 1B.9? Is it just another way of asking to find the amount of energy? I'm confused. Thank you :)
- Fri Oct 11, 2019 1:00 am
- Forum: Properties of Light
- Topic: High Intensity
- Replies: 5
- Views: 174
Re: High Intensity
Regarding the photoelectric effect, increasing the intensity of light means that you are increasing the amount of photons present. However, increasing the intensity of light does not allow for the displacement of electrons as the threshold is not meant since only the amplitude of the waves are chang...
- Fri Oct 11, 2019 12:56 am
- Forum: Limiting Reactant Calculations
- Topic: Theoretical yield
- Replies: 5
- Views: 398
Re: Theoretical yield
So in the problem, they already gave you the theoretical yield, which is the amount expected should the entire experiment should go according to plan. Since they already gave you the theoretical yield in moles, you just need to convert it to grams by multiplying by the molar mass of the compound.
- Fri Oct 11, 2019 12:40 am
- Forum: Empirical & Molecular Formulas
- Topic: Mass Percentage Question
- Replies: 9
- Views: 853
Re: Mass Percentage Question
To find the percent compositions of each element, you would first need to find the molar mass of Sr(NO2)2. Then, you would find the molar masses of each individual element and divide those molar masses by the molar mass of the compound. Then you multiple the decimal by 100%.
- Fri Oct 11, 2019 12:35 am
- Forum: Empirical & Molecular Formulas
- Topic: Formula Units
- Replies: 10
- Views: 379
Re: Formula Units
Formula units are basically the amount/number of something in a given bit of information. Formula units can be atoms or molecules. Basically, to find them you just need to multiple by Avogadro's number.
- Fri Oct 11, 2019 12:28 am
- Forum: Properties of Light
- Topic: Relationship between lambda and nu
- Replies: 5
- Views: 1110
Re: Relationship between lambda and nu
Essentially, the relationship between lambda (wavelength) and nu (frequency) is that when multiplied together, they equal the speed of light in a vacuum with the units meters per second.
- Fri Oct 11, 2019 12:21 am
- Forum: Limiting Reactant Calculations
- Topic: general questions
- Replies: 11
- Views: 978
Re: general questions
The reason as to why we need to identify the limiting reactant is because in order for us to solve how much of a final product can be formed, we need to know how many grams of it's constituents are available, especially if one to them will limit how much can be formed in the first place. Depending o...
- Thu Oct 03, 2019 9:36 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: F.3 part b
- Replies: 3
- Views: 186
Re: F.3 part b
If you refer back to the book in Example F.1, you can guess which will have the highest mass percentage based off of which of the elements is the heaviest. The formula is HNO3. Hydrogen contributes 1 gram, Nitrogen 14 grams, and Oxygen contributes 48 grams. So based off of this, we can guess that Ox...
- Thu Oct 03, 2019 9:30 pm
- Forum: Balancing Chemical Reactions
- Topic: HW question M15
- Replies: 2
- Views: 150
Re: HW question M15
Basically we have to use the limiting reactant because the extent of the amount of product formed is determined by the limiting reactant. It helps to think of it this way, if you're making trying to make 2 cakes that require 2 eggs each, but you only have 3 eggs, you can only make one cake. The maxi...
- Thu Oct 03, 2019 8:59 pm
- Forum: Balancing Chemical Reactions
- Topic: adding a product
- Replies: 6
- Views: 170
Re: adding a product
Yes. So basically, you just have to adjust the stoichiometric coefficient that way both sides of the reaction have the same masses.
- Thu Oct 03, 2019 8:38 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: #E5 part b)
- Replies: 2
- Views: 141
#E5 part b)
When finding how many years it would take to pick one mol of peas, am I supposed to start off the calculation by using my answer from part a? Because technically the moles of people is the same as the moles of peas if everyone picked one pea? I know how to get from seconds to years, but I'm stuck on...
- Thu Oct 03, 2019 6:02 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: HW #E9
- Replies: 3
- Views: 226
HW #E9
For this problem, I'm having trouble understanding how I'm supposed to go from Epsom salt to only the atoms of oxygen. I know I have to be able to get the moles of oxygen, but what steps do I need to take before? Thank you :)