Search found 91 matches
- Tue Dec 15, 2020 12:14 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam Scores
- Replies: 13
- Views: 882
Re: Final Exam Scores
Hi! Based on his email grades should be in by Saturday. Hope this helps!
- Fri Dec 11, 2020 11:27 am
- Forum: Significant Figures
- Topic: Things to remember for final?
- Replies: 20
- Views: 1202
Re: Things to remember for final?
Hi! I would say to memorize them, since we will only be given the periodic table and the formula sheet on the final.
- Fri Dec 11, 2020 11:23 am
- Forum: Administrative Questions and Class Announcements
- Topic: Are all questions on the final multiple choices?
- Replies: 29
- Views: 1363
Re: Are all questions on the final multiple choices?
Hi! All of the questions will be multiple choice. Hope this helps!
- Thu Dec 10, 2020 1:56 pm
- Forum: Student Social/Study Group
- Topic: Studying
- Replies: 13
- Views: 799
Re: Studying
Hi! I would also take a look at Khan Academy.
- Thu Dec 10, 2020 1:54 pm
- Forum: Air Pollution & Acid Rain
- Topic: acid rain
- Replies: 13
- Views: 1167
Re: acid rain
Acid rain was just a real life example of CO2 interaction. As CO2 rises, acidic rain increases. Hope this helps!
- Wed Dec 09, 2020 12:33 pm
- Forum: Identifying Acidic & Basic Salts
- Topic: Titration Diagram
- Replies: 5
- Views: 237
Re: Titration Diagram
Hi! ABC... were just data collected and are not the stoichiometric point. Hope this helps!
- Wed Dec 09, 2020 12:32 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: pH vs pKa
- Replies: 9
- Views: 919
Re: pH vs pKa
Ka is the acid constant, basically indicating the strength of the acid, and pKa is the -log of this acid constant, the lower the pKa the more acidic. Hope this helps!
- Wed Dec 09, 2020 12:27 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polarity
- Replies: 2
- Views: 109
Re: Polarity
Hi! Lecture 22 goes over this. I normally draw out the lewis structure and look at the dipole moments, and decide whether they cancel. If they cancel it is non polar.
- Wed Dec 09, 2020 10:57 am
- Forum: Administrative Questions and Class Announcements
- Topic: Lecture Videos Not Playing [ENDORSED]
- Replies: 16
- Views: 670
Re: Lecture Videos Not Playing [ENDORSED]
Hi! I am having the same issue :(
- Tue Dec 08, 2020 11:07 am
- Forum: Significant Figures
- Topic: sig fig
- Replies: 20
- Views: 985
Re: sig fig
Mauricio Maravilla 3C wrote:Will sig figs be important on the final?
Hi! They will be included in the final since it is cumulative and they take an important part on some of the calculations. I am not sure how prominent they will be on the final, but I would recommend going over it. Hope this helps!
- Tue Dec 08, 2020 11:04 am
- Forum: Bronsted Acids & Bases
- Topic: HF
- Replies: 15
- Views: 777
Re: HF
Why are acids with short bonds weak acids while acids with long bonds strong acids, and not the other way around? This is because a strong acid is supposed to give off a proton quite easily, if the there is a strong bond (short bonds) then the electrons and all the rest will be held tightly. Strong...
- Tue Dec 08, 2020 11:00 am
- Forum: Octet Exceptions
- Topic: Octet Exceptions
- Replies: 11
- Views: 1064
Re: Octet Exceptions
Maddie Turk Disc 2C wrote:Why can Xe hold more than 8 electrons?
This is because as I said in my last post, the d-orbital can accommodate more than 8 electrons. Hope this helps!
- Tue Dec 08, 2020 10:58 am
- Forum: Octet Exceptions
- Topic: Octet Exceptions
- Replies: 11
- Views: 1064
Re: Octet Exceptions
Hi! The octet executions include group 13, which don't often complete the octet guideline, this is because they are basically in the middle and would need 5 electrons! Starting with period 3 and below, these elements can have an extended octet due to the d orbital. Hope this helps!
- Mon Dec 07, 2020 12:54 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: Deciding which part of the salt affects pH
- Replies: 4
- Views: 224
Re: Deciding which part of the salt affects pH
Hi! So first you will discard the part of the salt that you know will act neutral, for example group one and group 2. If you are left with the anion part of the salt it is more likely that it will act as a base, and if you have the cation part of the salt left it will more likely act like an acid. H...
- Mon Dec 07, 2020 12:49 pm
- Forum: Student Social/Study Group
- Topic: Finals Study Things
- Replies: 27
- Views: 1281
Re: Finals Study Things
Thank you! I find this very helpful!
- Fri Dec 04, 2020 2:13 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acid Bond Strength
- Replies: 5
- Views: 266
Re: Acid Bond Strength
Hi! Bond strength and bond length are related, the stronger the bond length the shorter it is. So when considering bond length you are also considering the strength. But as said in the post above, we are also considering the stability of the anion, so resonance and electronegativity. Hope this helps!
- Fri Dec 04, 2020 2:10 pm
- Forum: Resonance Structures
- Topic: Stability
- Replies: 13
- Views: 649
Re: Stability
Resonance structures are more stable because of the delocalization. Hope this helps!
- Thu Dec 03, 2020 10:56 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Number
- Replies: 8
- Views: 436
Re: Coordination Number
Hi! Coordination number is the number of bonds that central atom has. Hope this helps!
- Thu Dec 03, 2020 10:52 am
- Forum: Lewis Acids & Bases
- Topic: Lewis Acids & Bases
- Replies: 12
- Views: 1068
Re: Lewis Acids & Bases
Hi! I am not sure what you learned in high school about acids and bases, but you can look at it in two ways:
1.Acids-accept pair of electrons
Bases-Donate pair of electrons
2. Acids-donate protons
Bases-accept protons
Hope this helps!
1.Acids-accept pair of electrons
Bases-Donate pair of electrons
2. Acids-donate protons
Bases-accept protons
Hope this helps!
- Wed Dec 02, 2020 12:45 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Charges on Metals
- Replies: 3
- Views: 255
Re: Charges on Metals
Hi! So you find the charge the of the Na ion by looking at its position in the periodic table. Remember that all the elements want to reach the a stable state, which is the position of the noble gasses. Na is closer to the Neon noble gas then it is to the Argon noble gas, so to reach the position of...
- Wed Dec 02, 2020 12:37 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: How to find Oxidation Numbers
- Replies: 4
- Views: 279
Re: How to find Oxidation Numbers
Hi! I don't think we are supposed to memorize them, they are often given. Hope this helps!
- Wed Dec 02, 2020 12:36 pm
- Forum: Naming
- Topic: Oxidation State
- Replies: 16
- Views: 623
Re: Oxidation State
Hi! Oxidation state is the charge. Hope this helps!
- Wed Dec 02, 2020 12:33 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: oxidation number with outside bracket charge
- Replies: 4
- Views: 248
Re: oxidation number with outside bracket charge
Hi! So the charge outside the brackets indicates the overall charge, so the the inside charges should equal 2-. Hope this helps!
- Tue Dec 01, 2020 10:57 am
- Forum: Naming
- Topic: Ligand Names
- Replies: 3
- Views: 198
Re: Ligand Names
I think we are expected to memorize them. Hope this helps!
- Tue Dec 01, 2020 10:57 am
- Forum: Ionic & Covalent Bonds
- Topic: Homework due date
- Replies: 49
- Views: 2048
Re: Homework due date
Hello! It is due on Sunday at 11:59pm. Hope this helps!
- Tue Dec 01, 2020 10:56 am
- Forum: Naming
- Topic: Oxidation Number while Naming
- Replies: 9
- Views: 425
Re: Oxidation Number while Naming
Hello! So Dr.Lavelle got an oxidation number 2 for cobalt because we know NH3 is neutral, H20 is neutral, but cl has a negative charge of 1. There are 2 Cl so we know there is currently a -2 charge, however we know there is an overall charge of 0 so Co has to be 2+to get rid of the 2- charge. Hope t...
- Mon Nov 30, 2020 11:54 am
- Forum: Naming
- Topic: Greek Prefixes
- Replies: 5
- Views: 194
Re: Greek Prefixes
Hi! It is the ligand where you add the Bis-, Tris...etc but you still leave the greek prefixes. Hope this helps!
- Mon Nov 30, 2020 11:51 am
- Forum: Bond Lengths & Energies
- Topic: London Dispersion Forces/ van der Waal forces
- Replies: 8
- Views: 678
Re: London Dispersion Forces/ van der Waal forces
LDF and van der Waals forces are the same thing, and any compound can undergo LDF because of their fluctuating property. Hope this helps!
- Mon Nov 30, 2020 11:48 am
- Forum: Biological Examples
- Topic: Hemoglobin vs. Myoglobin
- Replies: 30
- Views: 1223
Re: Hemoglobin vs. Myoglobin
Hi! Hemoglobin is the transfer of oxygen in the blood and myoglobin is the transfer of oxygen in muscle. Like Dr.Lavelle mentioned there will be more oxygen transported in the blood since hemoglobin is made up of myoglobin.
- Fri Nov 27, 2020 2:47 pm
- Forum: Student Social/Study Group
- Topic: Final Exam Tips
- Replies: 24
- Views: 898
Re: Final Exam Tips
Hi! I like to go over my notes and just do the problems from the textbook.
- Fri Nov 27, 2020 2:46 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shape Names
- Replies: 50
- Views: 2291
Re: Shape Names
Hi! The shape of which you described is called angular or bent.
- Thu Nov 26, 2020 11:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem Community Posts during Thanksgiving break
- Replies: 10
- Views: 498
Re: Chem Community Posts during Thanksgiving break
Lakshmi Davuluri 3K wrote:Aliya 2J wrote:If we stacked up with 40 from before, do we need to do more to have them be from this week?
I think so. I think we need to have at least five posts per week
Hi! This is right, it is 5 points per week. So you are supposed to have a total of 40 points by the end of the week.
- Thu Nov 26, 2020 11:47 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Chart
- Replies: 18
- Views: 872
Re: VSEPR Chart
Hi! We will have to memorize the shapes, we will only be given the periodic table and the formula sheet.
- Wed Nov 25, 2020 1:10 pm
- Forum: Student Social/Study Group
- Topic: Big Sad: Midterm 2
- Replies: 86
- Views: 5448
Re: Big Sad: Midterm 2
BoparaiAdeshsurjit2I wrote:Does anybody know the grading scheme. If 50% is needed to pass how much do you need to get an A?
Hello! So there are a total of 500 points and to get an A you can only miss 5 points. Hope this helps!
- Wed Nov 25, 2020 1:03 pm
- Forum: Hybridization
- Topic: Sp3d or dsp3
- Replies: 22
- Views: 2101
Re: Sp3d or dsp3
Hello! Dr.Lavelle mentioned in lecture that both of these notations work. Hope this works!
- Tue Nov 24, 2020 1:53 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma and pi bonds relation to covalent bonds
- Replies: 6
- Views: 288
Re: Sigma and pi bonds relation to covalent bonds
Hi! So sigma and pi bonds are both covalent bonds. When there exists one single bond we know it is sigma, and when there is a double bond, one of the bonds will be sigma and the other pi. Hope this helps!
- Tue Nov 24, 2020 1:50 pm
- Forum: Sigma & Pi Bonds
- Topic: Rotation of sigma and pi bonds
- Replies: 5
- Views: 261
Re: Rotation of sigma and pi bonds
Hi! So you will just know that rotation won't happen if there is a pi bond, because as you just said pi bond when rotated will break its bond. Hope this helps!
- Mon Nov 23, 2020 1:52 pm
- Forum: Octet Exceptions
- Topic: Radical Life Span
- Replies: 4
- Views: 189
Re: Radical Life Span
Hello! Radicals do not last very long, because they are highly reactive. Radicals arise when a photon breaks a bond and leaves a molecule with an odd number of electrons. Hope this helps!
- Mon Nov 23, 2020 1:45 pm
- Forum: Hybridization
- Topic: Lecture example ethene
- Replies: 9
- Views: 469
Re: Lecture example ethene
Hi! I am also confused on the first part of your question, but I think I can explain the second part. So because the the gap between the "regular" atomic orbital space between 2p and 2s is larger than the gap between the the hybridized and the 2p then there can be no paired electrons. Hope...
- Fri Nov 20, 2020 11:09 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: LDF forces
- Replies: 9
- Views: 408
Re: LDF forces
Hi! So all molecules experience LDF, since they are fluctuating. Hope this helps!
- Fri Nov 20, 2020 11:08 am
- Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
- Topic: Boiling and Melting point
- Replies: 24
- Views: 2788
Re: Boiling and Melting point
Hi! So molecules with higher boiling and melting points have stronger intermolecular forces. It takes more energy to break the bonds. Hope this helps!
- Thu Nov 19, 2020 9:05 am
- Forum: Bond Lengths & Energies
- Topic: Interaction Potential Energy
- Replies: 3
- Views: 212
Re: Interaction Potential Energy
Agree with last post, but I would like to add it is negative because attraction is happening (negative x negative =positive) and repulsion would be positive (positive x positive = positive or negative x negative= negative)
- Thu Nov 19, 2020 9:02 am
- Forum: Student Social/Study Group
- Topic: Big Sad: Midterm 2
- Replies: 86
- Views: 5448
Re: Big Sad: Midterm 2
Hi! As professor Lavelle said you can still pass, you just need a 50% to pass. You can do it! I felt better on this midterm than the last.
- Wed Nov 18, 2020 11:31 am
- Forum: Student Social/Study Group
- Topic: Midterm 2
- Replies: 19
- Views: 931
Re: Midterm 2
I mainly focus on the textbook problems and the learning objectives.
- Wed Nov 18, 2020 11:26 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: bond angles
- Replies: 16
- Views: 1136
Re: bond angles
We are not required to know the bond angles, but we are able to tell if the bond angle will be less. If there are lone pairs, it will "squish" the bond angles, making the angle smaller.
- Tue Nov 17, 2020 12:45 pm
- Forum: Bond Lengths & Energies
- Topic: Higher Melting Point
- Replies: 10
- Views: 1237
Re: Higher Melting Point
Hi! NaCl has ion-ion interaction which is stronger than dipole-dipole interactions of HCl, so it will take more heat to break NaCl. Hope this helps!
- Tue Nov 17, 2020 12:43 pm
- Forum: Lewis Structures
- Topic: Most stable/ resonance structure
- Replies: 3
- Views: 194
Re: Most stable/ resonance structure
Hi! So I agree with the posts above. But I would like to clarify that that the resonance structures are already implied to have the most stable charge.
- Mon Nov 16, 2020 11:52 am
- Forum: Bond Lengths & Energies
- Topic: Valence electrons of nitrogen
- Replies: 10
- Views: 423
Re: Valence electrons of nitrogen
Hi! Nitrogen in fact has 5 valence electrons, but what he meant was that nitrogen will follow the octet guideline.
- Mon Nov 16, 2020 11:50 am
- Forum: Bond Lengths & Energies
- Topic: Hydrogen Bonding
- Replies: 13
- Views: 364
Re: Hydrogen Bonding
Hi! I don't think there are any exceptions.
- Sun Nov 15, 2020 1:55 pm
- Forum: Student Social/Study Group
- Topic: Midterm 2
- Replies: 22
- Views: 708
Re: Midterm 2
Hello! I was Wondering whether all the question on the midterm are from the assigned problems, or is just some? Thank you!
- Fri Nov 13, 2020 12:08 pm
- Forum: Student Social/Study Group
- Topic: Midterm 2
- Replies: 22
- Views: 708
Re: Midterm 2
Hi! I will mainly focus on the textbook problems, since they can appear in the test. But I will also review the sapling homework. All practice problems help! Hope this helps!
- Fri Nov 13, 2020 12:05 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Rules for Assigning Shape
- Replies: 6
- Views: 261
Re: Rules for Assigning Shape
Hi! You can still assign a shape even if the atoms connected to the central atom are different. The shape depends on how many atoms are connected to the central atom. The fact that that the atoms are not identical only affects the angle we assign to them. Hope this helps!
- Thu Nov 12, 2020 11:02 am
- Forum: Coordinate Covalent Bonds
- Topic: When do we use it
- Replies: 9
- Views: 339
Re: When do we use it
Coordinate covalent bond is when one atom shares two electrons (the donor) and the accepting atom just takes them. This often occurs when the acceptor does not get the 8 electrons (octet guideline) from the bonds with the other atoms.
- Thu Nov 12, 2020 10:58 am
- Forum: Dipole Moments
- Topic: induced dipole vs dipole
- Replies: 11
- Views: 857
Re: induced dipole vs dipole
Dipole dipole have permanent dipole moments, while induced dipole induced dipole can only occur in a non polar reaction (e.g I^2 Cl^2...). Hope this helps!
- Wed Nov 11, 2020 12:55 pm
- Forum: Electronegativity
- Topic: Determining Permanent Dipole
- Replies: 3
- Views: 675
Re: Determining Permanent Dipole
Hello! An induced dipole induced dipole interaction only happens when there is a non polar interaction, meaning that the atoms are the same (e.g I^2, Cl^2...etc). A dipole -dipole interaction occurs when there is an unequal share of electrons (but it is not an ionic interaction). Hope this helps!
- Wed Nov 11, 2020 12:51 pm
- Forum: Lewis Structures
- Topic: Hydrogen in Lewis Structures
- Replies: 5
- Views: 239
Re: Hydrogen in Lewis Structures
Hi! Hydrogen can only have 2 electrons, this is because it is in the first orbital 1s, and you can have two electrons in it. Hope this helps!
- Tue Nov 10, 2020 11:10 am
- Forum: Bond Lengths & Energies
- Topic: Dipole
- Replies: 7
- Views: 128
Re: Dipole
I would say Dipole means an unequal sharing of electrons, which would imply that partial charge exists. Hope this helps!
- Tue Nov 10, 2020 11:07 am
- Forum: Lewis Acids & Bases
- Topic: Determining Lewis Acids and Lewis Bases
- Replies: 5
- Views: 178
Re: Determining Lewis Acids and Lewis Bases
Hi! I would recommend drawing out the Lewis Structure. Lewis acids accept electrons and Lewis bases donate electrons. Hope this helps!
- Mon Nov 09, 2020 12:16 pm
- Forum: Bond Lengths & Energies
- Topic: bond lengths
- Replies: 9
- Views: 429
Re: bond lengths
Bond lengths are sometimes also determined by size. For example, the bigger the atom, the larger the distance, so the longer the bond length. Hope this helps!
- Mon Nov 09, 2020 12:12 pm
- Forum: Ionic & Covalent Bonds
- Topic: Hydrogen Bonds [ENDORSED]
- Replies: 9
- Views: 502
Re: Hydrogen Bonds [ENDORSED]
Hi! Water molecules do have a dipole moment so an interaction between water molecules are in fact dipole dipole interactions. Yet, the interaction between water molecules is big that they start to form a strong bond (hydrogen bond), although not as strong as covalent bonds. Hope this helps!
- Fri Nov 06, 2020 12:17 pm
- Forum: Lewis Structures
- Topic: Simplifying Formal Charge?
- Replies: 3
- Views: 135
Re: Simplifying Formal Charge?
The formal charge you want to get is 0, since the molecules will be more stable in this state. So perhaps that is what simplifying formal charge may imply. Hope this helps!
- Fri Nov 06, 2020 12:15 pm
- Forum: Student Social/Study Group
- Topic: Syllabus
- Replies: 13
- Views: 614
Re: Syllabus
Hi! If you need any sort of clarification I can help!
- Fri Nov 06, 2020 12:14 pm
- Forum: Octet Exceptions
- Topic: Group 13 Elements
- Replies: 13
- Views: 450
Re: Group 13 Elements
Hello! It is all of group 13 elements that are an exception to the octet rule. Hope this helps!
- Thu Nov 05, 2020 11:01 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Lewis structures and formal charge
- Replies: 4
- Views: 122
Re: Lewis structures and formal charge
Could someone explain a bit more on why atoms with high electron affinities would be more stable with a negative formal charge and vice versa? Thanks! I can try to explain. See, if an atom has high electron affinity (meaning it wants another electron "very badly") then it is unstable with...
- Thu Nov 05, 2020 10:56 am
- Forum: Properties of Light
- Topic: Wavelength
- Replies: 26
- Views: 1204
Re: Wavelength
Wavelength should be written in meters, since it that is the correct si units. It just happens that sometimes we get an answer like with x10^-9 meters, and that is the same thing as nanometers. So, it may just be easier to refer to our answer in nanometers. And visible light is mainly all x10^-9 so ...
- Wed Nov 04, 2020 11:39 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Are there subshells past f?
- Replies: 28
- Views: 1033
Re: Are there subshells past f?
Hello! There are subshells past f, but we do not need to know them for this class. Hope this answers your question!
- Wed Nov 04, 2020 4:25 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Scores
- Replies: 28
- Views: 1123
Re: Midterm Scores
Our midterm, chemistry community, and homework points will all be release tomorrow (Thursday) afternoon. Hope this helps!
- Tue Nov 03, 2020 4:01 pm
- Forum: Trends in The Periodic Table
- Topic: Noble Gas Electron Affinity
- Replies: 6
- Views: 367
Re: Noble Gas Electron Affinity
Hi! Noble gasses don't just have a low affinity, they have 0 affinity. Hope this helps!
- Mon Nov 02, 2020 6:54 pm
- Forum: *Shrodinger Equation
- Topic: Midterm Scores
- Replies: 30
- Views: 1190
Re: Midterm Scores
The scores will be released on Thursday. Hope this helps!
- Mon Nov 02, 2020 6:48 pm
- Forum: Student Social/Study Group
- Topic: Midterm 2
- Replies: 31
- Views: 1167
Re: Midterm 2
I believe the last eight bulletin points will be tested on the second midterm. The second midterm is supposed be on week 7. Hope this helps!
- Sat Oct 31, 2020 12:56 am
- Forum: Student Social/Study Group
- Topic: How to relax
- Replies: 168
- Views: 21125
Re: How to relax
I often watch my favorite shows and play with my dog.
- Thu Oct 29, 2020 6:39 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem 14A Website
- Replies: 5
- Views: 309
Re: Chem 14A Website
I can confirm that's the correct password to the website.
- Thu Oct 29, 2020 6:37 pm
- Forum: Properties of Light
- Topic: Midterm
- Replies: 42
- Views: 1388
Re: Midterm
Hello! So we take the midterm during discussion section. It will be multiple choice and must be completed in 50 min (with an extra 6 min given to us. Hope this helps!
- Wed Oct 28, 2020 12:07 am
- Forum: Photoelectric Effect
- Topic: Work function or incoming light
- Replies: 6
- Views: 166
Re: Work function or incoming light
When the problem is asking for the energy to remove it is talking about the threshold energy. Hope this helps!
- Mon Oct 26, 2020 11:56 pm
- Forum: Properties of Light
- Topic: increasing intensity
- Replies: 5
- Views: 212
Re: increasing intensity
Increasing intensity of light does not increase energy, it increases the photons per energy. I always remember this concept by thinking about the cross country analogy. Hope this helps!
- Fri Oct 23, 2020 3:56 pm
- Forum: Significant Figures
- Topic: Quick Sig Fig Question with Addition/Subtraction
- Replies: 7
- Views: 435
Re: Quick Sig Fig Question with Addition/Subtraction
Hi! I usually round at the end. Hope this helps!
- Thu Oct 22, 2020 12:37 pm
- Forum: DeBroglie Equation
- Topic: De Brogile Wavelength Car Ex. from Lecture 8
- Replies: 7
- Views: 325
Re: De Brogile Wavelength Car Ex. from Lecture 8
Hi! So Professor Lavelle said that the detectable wavelength is x10^-15 or greater. Hope this helps!
- Wed Oct 21, 2020 11:01 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Exam
- Replies: 7
- Views: 289
Re: Exam
Hi! Based on the email we received today, we will be able to use a scientific calculator, and we should print the periodic table before the exam to have it at hand. Hope this helps!
- Tue Oct 20, 2020 8:40 pm
- Forum: Balancing Chemical Reactions
- Topic: H7
- Replies: 4
- Views: 218
Re: H7
Hi! I am not very sure if we are expected to memorize compound names, but just to be safe I would say to memorize the common ones. Hope this helps!
- Mon Oct 19, 2020 7:28 pm
- Forum: SI Units, Unit Conversions
- Topic: SI units
- Replies: 9
- Views: 192
Re: SI units
Hi! Wavelengths are supposed to be measured in meters (because of SI units), but Dr. Lavelle often writes it out in nm since it is just "easier" to say it than having to write x10-^9 m every time. Hope this helps!
- Fri Oct 16, 2020 5:32 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Sapling HW Grade [ENDORSED]
- Replies: 10
- Views: 932
Re: Sapling HW Grade [ENDORSED]
You will not lose points if you use the hints
- Fri Oct 16, 2020 12:07 am
- Forum: Properties of Light
- Topic: intensity, photons, and frequency
- Replies: 7
- Views: 232
Re: intensity, photons, and frequency
Hi! Increasing the intensity of light increases the number of photons, but does not increase the energy per photons, meaning the frequency will not increase. Hope this helps!
- Wed Oct 14, 2020 11:20 pm
- Forum: General Science Questions
- Topic: Balancing equations
- Replies: 19
- Views: 2488
Re: Balancing equations
Hi! There are different approaches to balancing an equation, but there should only be one answer. Hope this helps!
- Wed Oct 14, 2020 11:17 pm
- Forum: Significant Figures
- Topic: SI UNITS
- Replies: 12
- Views: 468
Re: SI UNITS
There are rules to determine how many significant figures you should be using. It will always depend on the problem. There are rules available on his website. Hope this helps!
- Tue Oct 13, 2020 7:37 pm
- Forum: Empirical & Molecular Formulas
- Topic: Compounds can Have the Same Molecular Formulas
- Replies: 4
- Views: 242
Re: Compounds can Have the Same Molecular Formulas
Hi! It is possible if they are isomers, meaning they have same number of atoms but are arranged differently.
- Tue Oct 13, 2020 12:30 am
- Forum: Significant Figures
- Topic: What is the purpose of significant figures?
- Replies: 17
- Views: 1088
Re: What is the purpose of significant figures?
The purpose of scientific figures is to help you get a more precise answer. Hope this helps!
- Fri Oct 09, 2020 4:12 pm
- Forum: Balancing Chemical Reactions
- Topic: State of matter in reaction
- Replies: 9
- Views: 245
Re: State of matter in reaction
No, the state of matter shouldn’t affect the way you balance the chemical equations. But you should note the state of matter to get full credit.
- Thu Oct 08, 2020 10:07 pm
- Forum: Balancing Chemical Reactions
- Topic: Periodic Table
- Replies: 66
- Views: 4671
Re: Periodic Table
Hi! I believe the periodic table will be given to us during tests. Hope this helps!
- Wed Oct 07, 2020 6:24 pm
- Forum: Balancing Chemical Reactions
- Topic: Fractions
- Replies: 34
- Views: 1345
Re: Fractions
Hello! I think it is preferred to have stoichiometric coefficients as whole numbers, since Dr. Lavelle mentioned how to do it.
- Tue Oct 06, 2020 8:52 pm
- Forum: Empirical & Molecular Formulas
- Topic: Emprical Formulas Ever Larger than Molecular? [ENDORSED]
- Replies: 26
- Views: 1844
Re: Emprical Formulas Ever Larger than Molecular? [ENDORSED]
Empirical formulas are never larger than their molecular formulas since empirical formulas are the smallest ratio (simplification) of the molecular formulas. For example, imagine 5/10 being the molecular formula and its simplification would be 1/2 (suppose this is the empirical formula), the simplif...
- Mon Oct 05, 2020 1:51 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Units for Dilution Equation [ENDORSED]
- Replies: 23
- Views: 2212
Re: Units for Dilution Equation [ENDORSED]
You should use Litters because molarity's units are in fact mol.L^-1.