Search found 88 matches
- Wed Jul 24, 2019 11:58 am
- Forum: Octet Exceptions
- Topic: Lewis Acids and Bases
- Replies: 10
- Views: 1377
Re: Lewis Acids and Bases
Lewis acids accept a pair of electrons and Lewis bases donate a pair of electrons. So an example would be BF3 and NH3. Where NH3 can form a bond with BF3 by donating its electron pair to boron. In this example BF3 is a Lewis acid and NH3 is a Lewis acid.
- Wed Jul 24, 2019 11:48 am
- Forum: *Molecular Orbital Theory Applied To Transition Metals
- Topic: prefix
- Replies: 3
- Views: 1257
Re: prefix
Greek prefixes are used to designate the number of each type of ligand in the complex ion, e.g. di-, tri- and tetra-. If the ligand already contains a Greek prefix (e.g. ethylenediamine) or if it is polydentate ligands (ie. can attach at more than one binding site) the prefixes bis-, tris-, tetrakis...
- Wed Jul 24, 2019 11:24 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Rotations and Shape
- Replies: 4
- Views: 705
Re: Rotations and Shape
No we won’t have to know how many rotations but it is an important concept in my opinion because if a question asks how many places a ligand can bind you would have to draw the molecule out and then see how many lone pairs it has to donate to figure out if it’s monodentate, bidentate and etc.
- Wed Jul 24, 2019 11:03 am
- Forum: *Molecular Orbital Theory Applied To Transition Metals
- Topic: definition
- Replies: 4
- Views: 1364
Re: definition
Ligands are ions or neutral molecules that bond to a central metal atom or ion. Ligands act as Lewis bases (electron pair donors), and the central atom acts as a Lewis acid (electron pair acceptor). Ligands have at least one donor atom with an electron pair used to form covalent bonds with the centr...
- Wed Jul 24, 2019 10:59 am
- Forum: *Molecular Orbital Theory Applied To Transition Metals
- Topic: coordination compound
- Replies: 2
- Views: 1088
Re: coordination compound
A coordination complex is the product of a Lewis acid-base reaction in which neutral molecules or anions (called ligands) bond to a central metal atom (or ion) by coordinate covalent bonds. The coordination sphere of a coordination compound or complex consists of the central metal atom/ion plus its ...
- Wed Jul 24, 2019 10:55 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Why is AX3E2 linear?
- Replies: 8
- Views: 1476
Re: Why is AX3E2 linear?
AX3E2. From this we can see that the central atom has 5 areas of electron density so the shape is trigonal bipyramidal. Now when it comes to naming the shape only the molecules connected to it count towards its name and we can see that only 3 molecules are attached. Now for a trigonal bipyramidal wh...
- Wed Jul 17, 2019 10:36 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Which do you prioritize first
- Replies: 10
- Views: 1218
Re: Which do you prioritize first
Prioritize the valence electron/octet guideline and then the charges. For charges you want the lowest charges possible and the separation of charges.
- Wed Jul 17, 2019 10:30 am
- Forum: Ionic & Covalent Bonds
- Topic: Inter and Intra
- Replies: 8
- Views: 2603
Re: Inter and Intra
I don’t know if this will help you remember the definition but the prefix intra means within,inside, on the inside and the prefix inter means between. So using that logic intermolecular forces would be forces between molecules and intramolecular forces would mean forces inside the molecule like cova...
- Wed Jul 17, 2019 10:23 am
- Forum: Ionic & Covalent Bonds
- Topic: Order of electron loss in ion formation
- Replies: 4
- Views: 746
Re: Order of electron loss in ion formation
The highest energy level electron would be lost first. For elements in the 4th row it’s important to note that the 4s is a higher energy level than 3d so if the configuration only has 3d and 4s orbitals then 4s would be lost first.
- Wed Jul 17, 2019 10:04 am
- Forum: Ionic & Covalent Bonds
- Topic: Intermolecular farces
- Replies: 2
- Views: 621
Re: Intermolecular farces
dipole moment would be calculated by the electronegativity difference between the atoms then you use that to figure out the intermolecular force. The dipole moment cancels in CO2 due to the shape. N2 has no dipole moment because there is no electronegativity difference. So the only forces would Lond...
- Wed Jul 17, 2019 10:01 am
- Forum: Lewis Structures
- Topic: Molecule Formulas
- Replies: 5
- Views: 800
Re: Molecule Formulas
Yes we will be given the molecular formula unless it’s a question that wants us to find it like in test 1. The reason the textbook doesn’t write it out is because you have access to the book and can look it up in the book( or that is what I am assuming).
- Wed Jul 17, 2019 9:57 am
- Forum: Ionic & Covalent Bonds
- Topic: Dipoles
- Replies: 7
- Views: 1199
Re: Dipoles
I am not going to repeat what hanna said, but to answer your question about hydrogen bonds. Hydrogen bonds only occur with N, O, F that is attached to a hydrogen and it is a type of dipole dipole interaction.
- Thu Jul 11, 2019 4:43 pm
- Forum: Photoelectric Effect
- Topic: Which Equation Do I Use?
- Replies: 4
- Views: 931
Re: Which Equation Do I Use?
I would also like to note that if they don’t directly give you the energy of the photon, but give you frequency or wavelength then you will have to use the equations c=λν and E=hν to find the energy of the photon then plug it into the equation E(Photon) = Work function/threshold energy - Kinetic ene...
- Thu Jul 11, 2019 4:34 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ground State
- Replies: 13
- Views: 1479
Re: Ground State
So the ground state for the neutral copper is [Ar] 3d^(10) 4s^(1) and remember that if it is an ion like Cu+ you would have to remove the highest charged electron because it is easier to remove than a lower charge and in the configuration the highest in energy is 4s so it will be the easiest to remo...
- Thu Jul 11, 2019 4:32 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: ION WITH +1
- Replies: 4
- Views: 678
Re: ION WITH +1
If the question asks you to find the configuration of an ion you would have to first find the configuration of the neutral atom and then account for the charge of that ion. For example if it is a - charge you add an electron and if its + you remove an electron.
- Thu Jul 11, 2019 4:29 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration for 1st row transition metals
- Replies: 6
- Views: 1128
Re: Electron Configuration for 1st row transition metals
For the purposes of this course you only need to know Cu and Cr, but all the elements in those rows show the same pattern because it is more stable for the elements to be either have all the d orbital filled with electrons or half filled.
- Thu Jul 11, 2019 4:26 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Valence electrons
- Replies: 4
- Views: 677
Re: Valence electrons
Mn would have 7 valence electrons. If you look at the configuration which is [Ar] 3d^5 4s^2. You can see that there is 7 electrons which could possibly be used to bond and since its in the 4th period. Since argon is a Nobel gas the electrons in those states/orbitals will not bond because it is alrea...
- Thu Jul 11, 2019 4:21 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron configuration
- Replies: 3
- Views: 684
Re: Electron configuration
It depends on the question if they ask for the ‘full ground state’ then you cant use the short hand, but if they don’t then you could write it as [Ar] to represent that it lost the 2 electrons from the +2 charge. If the question states you can use the abbreviation then yes, if not then no.
- Wed Jul 03, 2019 11:18 am
- Forum: Photoelectric Effect
- Topic: work function
- Replies: 4
- Views: 892
Re: work function
This would be a multi step problem. First to use the equations E=hν and C=λν , if they gave you the frequency of the photon. Then once you have that information you could solve for the work function if they provided you with the kinetic energy of the ejected electron. Then you could use all the know...
- Wed Jul 03, 2019 11:07 am
- Forum: DeBroglie Equation
- Topic: Calculating Velocity
- Replies: 9
- Views: 1604
Re: Calculating Velocity
Depends on the know information you have. If you know the kinetic energy of an electron then you could use 1/2mv^2 or if you know the momentum of the electron then you could use p=mv. Also the units for momentum would be kg.m.s^-1.
- Wed Jul 03, 2019 11:03 am
- Forum: Administrative Questions and Class Announcements
- Topic: Solutions Manual for the 6th Edition of the Textbook
- Replies: 3
- Views: 9798
Re: Solutions Manual for the 6th Edition of the Textbook
You can try http://gen.lib.rus.ec/
Library genesis might have the pdf version or not I’m not too sure. Also you can download the pdf version of your books if your taking other classes at UCLA. It’s definitely a useful resource.
Library genesis might have the pdf version or not I’m not too sure. Also you can download the pdf version of your books if your taking other classes at UCLA. It’s definitely a useful resource.
- Wed Jul 03, 2019 10:56 am
- Forum: Balancing Chemical Reactions
- Topic: Elemental states [ENDORSED]
- Replies: 6
- Views: 892
Re: Elemental states [ENDORSED]
For the exams will the states always be given or would we have to extrapolate that information?
- Wed Jul 03, 2019 10:52 am
- Forum: Photoelectric Effect
- Topic: kinetic energy of electron
- Replies: 8
- Views: 1169
Re: kinetic energy of electron
When the energy of light(photon) is equal to the work function(threshold energy). For me it’s easier to think of it in terms of the law of conservation of energy and the equation: energy of light(photon) = threshold energy(work function) + kinetic energy of electron(excess energy in the form of kine...
- Wed Jul 03, 2019 10:39 am
- Forum: Einstein Equation
- Topic: Energy of photon [ENDORSED]
- Replies: 12
- Views: 1875
Re: Energy of photon [ENDORSED]
Like everyone stated before you would use both the equations C=λv and E=hv. It’s important to note that the equation with speed of light is only applicable to problems dealing with light. You can then reconfigure the equations to solve for the variable you are looking for.
- Wed Jul 03, 2019 10:33 am
- Forum: Photoelectric Effect
- Topic: Metals and Electrons
- Replies: 3
- Views: 583
Re: Metals and Electrons
Other than the metal becoming a cation are there any other structural changes in the metal? Like would the electron orbital be closer to the nucleus because of the loss of the electron?
- Fri Jun 28, 2019 11:22 am
- Forum: Molarity, Solutions, Dilutions
- Topic: the mole
- Replies: 4
- Views: 580
Re: the mole
Density is the ratio of mass to volume, mass/volume(either in liters or meters cubed). DENSITY is a physical property of matter, as each element and compound has a unique density associated with it. Density defined in a qualitative manner as the measure of the relative "heaviness" of objec...
- Fri Jun 28, 2019 10:58 am
- Forum: SI Units, Unit Conversions
- Topic: Use of Kelvin
- Replies: 6
- Views: 889
Re: Use of Kelvin
0 kelvin is the lowest possible temperature. Absolute zero is defined as 0 kelvin, which is the lowest possible temperature. Also it may be easier to remember that kelvin is a absolute Temperature scale so absolute 0 logically would mean 0 K.
- Fri Jun 28, 2019 10:47 am
- Forum: Empirical & Molecular Formulas
- Topic: Molar Mass vs. Atomic Weight
- Replies: 7
- Views: 1366
Re: Molar Mass vs. Atomic Weight
Atomic mass is related to a single element while molar mass is the total mass of the compound. So you would need to sum the atomic masses of the compound(molecular formula) to get the molar mass of the compound. It’s important to note that atomic mass and molar mass is g/mol.
- Fri Jun 28, 2019 10:33 am
- Forum: Empirical & Molecular Formulas
- Topic: Formulas
- Replies: 10
- Views: 2345
Re: Formulas
As previously stated the molecular formula can not be solved without knowing what the molar mass is. If you have the molar mass then you can divide the molar mass by the molar mass of the empirical formula, if you calculated the empirical formula. Now if you have the molar mass of the molecule and t...
- Fri Jun 28, 2019 10:04 am
- Forum: SI Units, Unit Conversions
- Topic: Limiting Reactants
- Replies: 5
- Views: 728
Re: Limiting Reactants
For the examples you provided Professor lavelle does not expect us to know the molecular formula, but for common things like diatomic molecules and water and carbon dioxide we may need to know what they are.
- Wed Jun 26, 2019 11:06 am
- Forum: Balancing Chemical Reactions
- Topic: Why do we balance chemical equations?
- Replies: 13
- Views: 8514
Re: Why do we balance chemical equations?
It is because of the concept of conservation of mass which states that in an isolated system mass can not be created nor destroyed by chemical reactions or physical transformations. Since the chemical reaction can not destroy or create mass the number of elements from the reactants must equal the nu...
- Sat Mar 16, 2019 1:13 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Lyndon's Review Sheets
- Replies: 9
- Views: 1363
Re: Lyndon's Review Sheets
He will be posting the working sheet which is already up. Just need to search up Pork Ramen and also he will not be posting the answer key.
- Sat Mar 16, 2019 1:11 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Yekan Final review slides and solutions 0312
- Replies: 8
- Views: 1256
Re: Yekan Final review slides and solutions 0312
Thank you for posting this! It was helpful with my studying!
- Sat Mar 16, 2019 1:09 pm
- Forum: Administrative Questions and Class Announcements
- Topic: LYNDON'S PORK RAMEN REVIEW
- Replies: 37
- Views: 7653
Re: LYNDON'S PORK RAMEN REVIEW
Thank you Lyndon for the help this quarter!
- Sat Mar 09, 2019 8:57 pm
- Forum: Second Order Reactions
- Topic: deriving the integrated rate laws
- Replies: 2
- Views: 344
Re: deriving the integrated rate laws
Also wanted to note that the rate laws on the constants and equation sheet will not be labeled which order it is for. So I would recommend getting familiar with the different formulas for zero, first and second order formulas and how to use them. As Saman has sated it may be helpful to know how to d...
- Sat Mar 09, 2019 8:47 pm
- Forum: First Order Reactions
- Topic: Pseudo-First-Order Reaction
- Replies: 5
- Views: 550
Re: Pseudo-First-Order Reaction
A reaction which is not first-order reaction naturally but made first order by increasing or decreasing the concentration of one or the other reactant is known as Pseudo first order reaction. In pseudo-first order reactions, we are basically isolating a reactant by increasing the concentration of th...
- Sat Mar 09, 2019 8:36 pm
- Forum: Student Social/Study Group
- Topic: Note Taking
- Replies: 145
- Views: 19066
Re: Note Taking
I use an iPad Pro with notability for hand written notes as well as recording the lectures. After the lecture I take some time to review the notes and periodically try to retrieve the information that he covered in lecture and concepts throughout the week to refresh my memory and using my notes as a...
- Sat Mar 09, 2019 8:29 pm
- Forum: Student Social/Study Group
- Topic: Final
- Replies: 24
- Views: 2255
Re: Final
Review sessions information is now posted on his website. Started today and there are review sessions until the Saturday before the exam.
- Sat Mar 09, 2019 8:10 pm
- Forum: General Rate Laws
- Topic: Rate Laws
- Replies: 8
- Views: 725
Re: Rate Laws
The rate laws will be given but will not be labeled which order it is. I recommend familiarizing yourself with the derivative and integrTed rate laws so you can recognize which is for which order of reaction.
- Sat Mar 09, 2019 7:53 pm
- Forum: General Rate Laws
- Topic: Overall sum
- Replies: 7
- Views: 799
Re: Overall sum
The overall reaction would be the sum of all the exponents in the rate law for that reaction.
- Sat Mar 09, 2019 10:55 am
- Forum: General Rate Laws
- Topic: Mechanisms?
- Replies: 3
- Views: 407
Re: Mechanisms?
A reaction mechanism is the step by step sequence of elementary reactions by which overall chemical change occurs. A chemical mechanism is a theoretical conjecture that tries to describe in detail what takes place at each stage of an overall chemical reaction.
- Tue Feb 26, 2019 12:21 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Moles in -nFEcell
- Replies: 5
- Views: 654
Re: Moles in -nFEcell
As everyone stated before n represents the moles of electrons. To figure it out you could do the reduction and oxidation half-reactions for the reaction to calculate it. Balance the reactions so there are equal number of electrons for both the oxidation and reduction half reactions. I just want to n...
- Tue Feb 26, 2019 12:06 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell diagram help.
- Replies: 2
- Views: 305
Cell diagram help.
I had a question about the cell diagram. If the anode or cathode has elements that do not go under a phase change we annotate it as Fe3+(aq),Fe2+(Aq)ΙPt(s) right? Also when there is no phase change and no metal we add a inert metal to the cell diagram right??
- Tue Feb 26, 2019 11:41 am
- Forum: Balancing Redox Reactions
- Topic: OH or H20
- Replies: 2
- Views: 328
Re: OH or H20
When balancing half reactions first balance the Oxygens with H2O then depending on the type of solution it is you either add H+ to balance the hydrogens from H20 (in an acidic solution, usually the question will explicitly state it) or OH to balance the H from H20 (basic solution).
- Sun Feb 17, 2019 1:09 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Heat and Entropy
- Replies: 3
- Views: 384
Re: Heat and Entropy
It is a multi-step process where first you use q=nCΔt and rearrange the equation to solve for the specific heat because the specific heat is needed to solve for ΔS=nCln(T2/T1).
- Sun Feb 17, 2019 1:05 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: adding entropy
- Replies: 5
- Views: 653
Re: adding entropy
If you are referring to the changes in entropy due to changes in temperature and volume then yes. Since entropy is a state function. You can add the entropy values due to changes in volume and temperature.
- Sun Feb 17, 2019 12:54 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Adding reaction entropies
- Replies: 8
- Views: 900
Re: Adding reaction entropies
Entropy is a STATE FUNCTION. So therefore entropy is path independant meaning that you only need the final and initial values to calculate the entropy.
- Mon Feb 11, 2019 2:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Thermochemistry Review Packet
- Replies: 4
- Views: 636
Re: Thermochemistry Review Packet
Thank you for the review session! I also thank you for posting these notes to help supplement my own notes and conceptual understanding of the material!
- Fri Feb 08, 2019 4:56 pm
- Forum: Ideal Gases
- Topic: atm vs. bar?
- Replies: 25
- Views: 2996
Re: atm vs. bar?
I think the most important part for atm and bar is to be consistent with the units throughout the calculations so you don’t get points deducted. I would really pay attention to the wording of the problem if they give you atm then just use atm throughout your calculations. Consistency is important, t...
- Fri Feb 08, 2019 4:50 pm
- Forum: Ideal Gases
- Topic: Lyndon's review session
- Replies: 7
- Views: 840
Re: Lyndon's review session
Lyndon is a very busy man... he hasn’t made the worksheets yet but he will over the weekend from what he told me. I believe it will be named hotdog because Dr.lavelle made a joke about naming it that and ... maybe just maybe it will be named HOTDOG! But don’t quote me on that. Also the time is at 7p...
- Fri Feb 08, 2019 4:45 pm
- Forum: Ideal Gases
- Topic: Reading the textbook
- Replies: 262
- Views: 156005
Re: Reading the textbook
I read the textbook but in a very organized way. Since there is a lot of information in the textbook which can sometimes make it confusing and hinders your comprehension. I use the outlines for each section and cater my reading to focus on the things that were on the outline. For example I would rea...
- Fri Feb 08, 2019 4:26 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Useful Summary of Thermodynamic Definitions
- Replies: 55
- Views: 18725
Re: Useful Summary of Thermodynamic Definitions
Just asking for clarification but for an Adiabatic isolated system as dr.lavelle stated that there can be exchange or more specificly loss of internal energy as work correct? So compared to an isolated system where there is no exchange of matter or energy because there is no surroundings therefore m...
- Fri Feb 08, 2019 4:17 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Adiabatic isolated system vs isolated system.
- Replies: 1
- Views: 295
Adiabatic isolated system vs isolated system.
Could anyone help me with these two terms. I know that a adiabatic isolated system is one with adiabatic boundaries where energy can leave as work and there is no exchange in matter or energy. An isolated system is one where there is no exchange of energy and matter. I am having difficulty understan...
- Wed Jan 30, 2019 4:32 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Best Method
- Replies: 7
- Views: 826
Re: Best Method
Methods one and three are more accurate than method 2. The reason is because for the bond enthalpy chart, it has the average values of the bond enthalpies and doesn’t take into consideration the reaction. Methods 1 and 3 should yield similar results that are more accurate than method 2. It really de...
- Wed Jan 30, 2019 4:19 pm
- Forum: Phase Changes & Related Calculations
- Topic: Standard State
- Replies: 6
- Views: 1866
Re: Standard State
Two elements are liquid in their standard state: mercury and bromine. Eleven elements are gas in their standard state. All of the noble gases (He, Ne, Ar, Kr, Xe, Rn) as well the halogens flourine and chlorine. Hydrogen, oxygen and nitrogen are the others. All other elements are solid in their stand...
- Wed Jan 30, 2019 4:15 pm
- Forum: Phase Changes & Related Calculations
- Topic: Standard entalpy of formation
- Replies: 6
- Views: 1057
Re: Standard entalpy of formation
Molecules in their standard state (most stable) have an standard enthalpy formation of zero. It is important to note “Standard” which refers to a specific pressure which is 1 atm and a specific heat which is 25 degrees celcius. If a molecule is in its most stable state at 1 atm and 25 degrees celciu...
- Thu Jan 17, 2019 10:59 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Acid and Base Equilibria
- Replies: 7
- Views: 692
Re: Acid and Base Equilibria
I also wanted to input that pH is also related to the concentration of Hydronium ions (H3O+). For example if you have a pH of 1 to convert that into concentration you would take the antilog of -1 (The reason you take the antilog is because pH=-log[H3O+] and we know that the ph is 1 so we solve for t...
- Thu Jan 17, 2019 10:27 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: sig figs
- Replies: 4
- Views: 526
Re: sig figs
I posted a photo further specifying significant figures for logs. But as it states on dr Lavelles PDF of “More on Significant figures” how ever many significant figures in the number your calculating is how ever many significant figures you have after the calculation.
- Thu Jan 17, 2019 10:19 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: 6A.23
- Replies: 2
- Views: 226
Re: 6A.23
Sorry could you specify what question it is? Also there is a solution manual errors pdf on Dr.Lavelles website (Chemistry Community). All solution manual errors would be on that pdf. If its not on there then you could always back track to see if there were any errors calculating.
- Fri Jan 11, 2019 2:47 pm
- Forum: Ideal Gases
- Topic: Use of the Ideal Gas law vs Combined Gas Law
- Replies: 2
- Views: 320
Re: Use of the Ideal Gas law vs Combined Gas Law
Thank You for the clarification! So, can I assume that if Professor Lavelle asks a question pertaining to finding Pressure, Temperature, Moles, or Volume to use the Ideal gas constant to calculate it, if I am given the other variables?
- Fri Jan 11, 2019 10:45 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Homework 11.39 Edition 6
- Replies: 4
- Views: 454
Re: Homework 11.39 Edition 6
We multiple it because we want to find the K(constant) for the given equation: 2BrCl(g) + H2(g) =(this is suppose to be the forward and reverse reaction) Br2(g) + 2 HCl(g). If you derive the Equilibrium constant for this equation it gives you: ([HCl]^2 [Br]^2)\([Brcl]^2 [H2]) If you add the equation...
- Fri Jan 11, 2019 10:33 am
- Forum: Ideal Gases
- Topic: Use of the Ideal Gas law vs Combined Gas Law
- Replies: 2
- Views: 320
Use of the Ideal Gas law vs Combined Gas Law
I am confused of when to use the Combined Gas Law. I know that if I am give moles and other information that I can calculate for Pressure, Temperature, or Volume, but when would I have to use the Combined Gas Law? If they change the variable and ask a question where the volume and temperature change...
- Thu Jan 10, 2019 10:49 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Homework 11.39 Edition 6
- Replies: 4
- Views: 454
Re: Homework 11.39 Edition 6
If I am not mistaken it is because when you multiple K1 and K2 (the equilibrium constant equation for both of the given chemical reactions) you the equilibrium constant for the given equation after you do the algebra and cancel out the Cl2. It makes more sense when you write out the Equilibrium cons...
- Fri Dec 07, 2018 12:54 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Calculate the strength of an acid?
- Replies: 3
- Views: 424
Re: Calculate the strength of an acid?
I don’t think we have to since it wasn’t really covered in lecture from what i remember, but i would remember the how to calculate pH and pOh which is -log[H] and -log[OH].
- Fri Dec 07, 2018 12:52 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Final Exam
- Replies: 3
- Views: 416
Final Exam
What exactly do we need to know from this section for the final exam?
- Fri Dec 07, 2018 12:45 pm
- Forum: Trends in The Periodic Table
- Topic: Ionization Energy and Electron Affinity Trend Exceptions
- Replies: 2
- Views: 712
Re: Ionization Energy and Electron Affinity Trend Exceptions
Also wanted to stated that the trend also applies to electronegativity as well.
Decreases down a column and increases acreage the row.
Decreases down a column and increases acreage the row.
- Sun Nov 25, 2018 9:32 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: How to state bond angles.
- Replies: 7
- Views: 779
Re: How to state bond angles.
Answering with slightly less than 109.5 is what Lavelle probably expects. From speaking with friends that took this course previously that would suffice for an answer.
- Sun Nov 25, 2018 9:06 am
- Forum: Bond Lengths & Energies
- Topic: Single, Double, Triple Bond Lengths
- Replies: 5
- Views: 1628
Re: Single, Double, Triple Bond Lengths
Single > double > triple bonds. My thought process is that since double and triple bonds have pi bonds, which are overlap/side-to-side orbital interactions the bonds have to be closer than a single.
- Sun Nov 25, 2018 8:54 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Linear structure with lone pairs
- Replies: 6
- Views: 665
Re: Linear structure with lone pairs
AX2, AXE, AXE2, and AX2E3 are the only linear structures.
- Sat Nov 03, 2018 10:25 pm
- Forum: Trends in The Periodic Table
- Topic: Periodic trends
- Replies: 4
- Views: 517
Re: Periodic trends
Thank you guys for posting this. Missed some lectures due to a concussion and you guys just saved my life.
- Sat Nov 03, 2018 10:17 pm
- Forum: *Particle in a Box
- Topic: Midterm
- Replies: 17
- Views: 4289
Re: Midterm
Sorry I cant find the midterms from last year would the person that found it be so kind enough to elaborate so use laymen can find it to practice?
- Sat Nov 03, 2018 10:10 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Cheat sheet or open notes? [ENDORSED]
- Replies: 2
- Views: 539
Re: Cheat sheet or open notes? [ENDORSED]
No cheat sheets sorry. I asked people that previously took this course and nope there will not be any cheet sheets or open notes allowed. The periodic table and list of constants and equations will be given unless things have changed like the last 2-3 quarters.
- Sat Nov 03, 2018 10:06 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Layout
- Replies: 3
- Views: 387
Re: Midterm Layout
Its completely free response.
- Sat Nov 03, 2018 9:52 pm
- Forum: DeBroglie Equation
- Topic: Momentum
- Replies: 10
- Views: 1473
Re: Momentum
I would recommend using a systematic approach to these kinds of problems. Just write the equation that you need to use to find the answer and if you don’t have all relevant information for that equation them most likely you would have to use another equation like de Broglie to get that information a...
- Sat Nov 03, 2018 9:28 pm
- Forum: Coordinate Covalent Bonds
- Topic: Coordinate Covalent Bond Definition
- Replies: 14
- Views: 1880
Re: Coordinate Covalent Bond Definition
Thanks for clarifying!
- Sat Nov 03, 2018 9:26 pm
- Forum: Resonance Structures
- Topic: Determine Number of Resonance Structures
- Replies: 2
- Views: 1628
Re: Determine Number of Resonance Structures
I don’t think knowing the possible resonance structures would be important. Working through some of the practice exams I got didn’t see any questions where they asked to draw all resonance structures or asking how many possible ones there are. So far I have been drawing the most stable Lewis structu...
- Sat Nov 03, 2018 8:53 pm
- Forum: Photoelectric Effect
- Topic: Question on kinetic energy
- Replies: 5
- Views: 742
Re: Question on kinetic energy
Thank you for the clarification.
- Sat Nov 03, 2018 8:51 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Exceptions to the Octet Rule
- Replies: 2
- Views: 258
Re: Exceptions to the Octet Rule
Thank you for these explanations. Y’all are my heroes.
- Sat Nov 03, 2018 8:45 pm
- Forum: Trends in The Periodic Table
- Topic: Ionic Radius
- Replies: 2
- Views: 314
Re: Ionic Radius
From my limited understanding Protons are what you should be mainly concerned about because the protons are what gives a positive charge for the electrons to be attracted to. Therefor the more protons the higher the positive charge and therefor electrons will be closer to the nucleus.
- Sat Nov 03, 2018 8:37 pm
- Forum: Photoelectric Effect
- Topic: Kinetic energy
- Replies: 11
- Views: 3343
Re: Kinetic energy
As stated before the Formula is used only to find the Kinetic energy but if you don’t have all the requested information I’m pretty sure you can also use de Broglie equation to help you find that portion. Since the equation is KE= 1/2 MV^2 and you don’t have velocity you can use de Broglie’s equatio...
- Sat Nov 03, 2018 8:31 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic vs Covalent Bonds
- Replies: 18
- Views: 1819
Re: Ionic vs Covalent Bonds
I just had a question. For Ionic and Covalent bonds would it be specifically one or would it be more accurate to say its one a spectrum? For example a Bond would have more ionic properties than covalent?
- Sat Nov 03, 2018 8:27 pm
- Forum: Lewis Structures
- Topic: Memorizing chemical formulas from their names?
- Replies: 3
- Views: 375
Re: Memorizing chemical formulas from their names?
From what my TA said there will be a few common ions that we will have to remember. Didn’t really specify which ones so I understand your pain. Just to be safe though I am remembering all the common ions that Lavelle posted on his site. But I think as long as you know the suffix and prefixes for ion...
- Sat Nov 03, 2018 1:09 pm
- Forum: Administrative Questions and Class Announcements
- Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
- Replies: 121
- Views: 22129
- Fri Oct 12, 2018 10:04 am
- Forum: General Science Questions
- Topic: Exams.
- Replies: 2
- Views: 337
Exams.
Will the formulas and constants always be given on the exams? I’m asking because for test 1 will we always be given them? Or will we have to memorize them as we go like for the midterms and finals?
- Fri Oct 12, 2018 9:59 am
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student [ENDORSED]
- Replies: 297
- Views: 452918
Re: Advice from a Medical Student [ENDORSED]
Thank you for the advice its very helpful since I will be taking the mcat sometime next year.
- Fri Oct 12, 2018 9:51 am
- Forum: Administrative Questions and Class Announcements
- Topic: Audio-Visual Assignments
- Replies: 4
- Views: 279
Re: Audio-Visual Assignments
No its not part of our grade. Looking at the syllabus it says nothing about the audio visual assignments. I believe its there to help the students that are rusty with chem topics before taking this like such as myself ...
- Fri Oct 12, 2018 9:46 am
- Forum: Student Social/Study Group
- Topic: Step-up program
- Replies: 1
- Views: 367
Step-up program
Does anyone know if the step up program covers material that the professor covere that week or if they also help with previous weeks materials if we are still struggling even after the practice questions/homework??
- Fri Oct 12, 2018 9:39 am
- Forum: Empirical & Molecular Formulas
- Topic: Empirical & Molecular Formulas
- Replies: 11
- Views: 1575
Re: Empirical & Molecular Formulas
Yes the molecular and empirical formulas can be the same. Just remember to calculate the molar mass of said compound. Since the empirical formula is the ratio of atoms in relation to the element with the lowest moles.