Because the first step is fast there will be a build up of products that eventually o back to being reactants in a reversible chem equation. The process will be assumed to be at equilibrium in the forward and reverse processes:)
hope this helps!
Search found 100 matches
- Wed Mar 10, 2021 12:36 pm
- Forum: Experimental Details
- Topic: Fast step at equilibrium [ENDORSED]
- Replies: 4
- Views: 458
- Wed Mar 10, 2021 12:34 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts in the Slow Step
- Replies: 17
- Views: 836
Re: Catalysts in the Slow Step
A catalyst will not appear in the overall reactions as it is not really apart of the process, but it an additive just meant to increase the rate:)
hope this helps!
hope this helps!
- Wed Mar 10, 2021 12:28 pm
- Forum: *Enzyme Kinetics
- Topic: catalyst vs intermediate
- Replies: 13
- Views: 835
Re: catalyst vs intermediate
Catalysts usually show up in the reactants of the first step, and intermediates are usually produced in the first step:) as well as intermediates become later reactants
hope this helps:)
hope this helps:)
- Wed Mar 10, 2021 12:25 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Pre-equilibrium approach [ENDORSED]
- Replies: 3
- Views: 218
Re: Pre-equilibrium approach [ENDORSED]
The pre-equilibrium approach is used wen we want to get rid of an intermediate as they are not included in the rate law:) if the first step was the slow then we would not need to continue the approx.
hope this helps:)
hope this helps:)
- Wed Mar 10, 2021 12:23 pm
- Forum: General Rate Laws
- Topic: Rate Law
- Replies: 6
- Views: 376
Re: Rate Law
The 1/2 is from the form 1/a where a is the coefficient of the reactant:) and the rest is just the differential of the reactant over time
hope this helps:)
hope this helps:)
- Thu Mar 04, 2021 8:25 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: first order of rxns
- Replies: 14
- Views: 701
Re: first order of rxns
Yes:) I would assume that n=1 for first order reactions, and similarly n=0 for zero order
hope this helps:)
hope this helps:)
- Thu Mar 04, 2021 8:22 pm
- Forum: Zero Order Reactions
- Topic: Half life
- Replies: 20
- Views: 893
Re: Half life
To calc the half life use the equation t1/2=[A]0/2k. but you must know the INITIAL concentration:) hope this helps!
- Thu Mar 04, 2021 8:21 pm
- Forum: *Organic Reaction Mechanisms in General
- Topic: K meaning
- Replies: 29
- Views: 2016
Re: K meaning
K is just the Boltzmann constant:) nothing too special as far as I know lol!
- Thu Mar 04, 2021 8:19 pm
- Forum: General Rate Laws
- Topic: Number of Reactants
- Replies: 26
- Views: 992
Re: Number of Reactants
I think that it is definitely possible to have more than 3, but for this class I'm pretty sure Lavelle will only focus on a max of 3 reactants:) hope this helps!
- Thu Mar 04, 2021 8:17 pm
- Forum: First Order Reactions
- Topic: 1st Order Reactions
- Replies: 29
- Views: 1747
Re: 1st Order Reactions
The ln[a] graph will be negatively linear whereas the [a] graph will be exponentially decreasing. Both graphs represent the first order, but it is only the y-axis value that is different
Hope this helps:)
Hope this helps:)
- Thu Feb 25, 2021 9:27 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cathode vs. Anode
- Replies: 8
- Views: 635
Re: Cathode vs. Anode
I would just look at the flow of the electrons!
Anodes are oxidized and cathodes are reduced:)
Hope this helps!
Anodes are oxidized and cathodes are reduced:)
Hope this helps!
- Thu Feb 25, 2021 9:17 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n in NFE
- Replies: 64
- Views: 2687
Re: n in NFE
The value of n is going to be the amount of electrons transferred:) you can find this out by doing the redox half reactions!
Hope this helps!
Hope this helps!
- Thu Feb 25, 2021 9:11 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: dilutions and Ecell
- Replies: 16
- Views: 3086
Re: dilutions and Ecell
Ecell= Ecathode-Eanode
So if there is a greater difference between the two chambers than the cell potential would increase. So it depends on which side the dilution is occurring on.
Hope this helps:)
So if there is a greater difference between the two chambers than the cell potential would increase. So it depends on which side the dilution is occurring on.
Hope this helps:)
- Thu Feb 25, 2021 9:05 pm
- Forum: Balancing Redox Reactions
- Topic: E naught
- Replies: 15
- Views: 854
Re: E naught
I just like to think of E naught as a constant that does not change for a reaction. And like others have said, it is an intensive property:)
Hope this helps!
Hope this helps!
- Thu Feb 25, 2021 9:00 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridge
- Replies: 30
- Views: 1263
Re: Salt Bridge
Hi:)
The salt bridge helps keep electrical neutrality! The positive and negative ions can evenly distribute between the anode and cathode sides.
The salt bridge helps keep electrical neutrality! The positive and negative ions can evenly distribute between the anode and cathode sides.
- Tue Feb 16, 2021 10:22 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy density
- Replies: 2
- Views: 194
Re: Enthalpy density
I would also ignore the sign in this case. The question is more so pertaining to the overall value as opposed to the sign of change(+/-)
Hope this helps:)
Hope this helps:)
- Tue Feb 16, 2021 10:20 am
- Forum: Calculating Work of Expansion
- Topic: Work and Delta V
- Replies: 20
- Views: 2363
Re: Work and Delta V
Yes you are correct!:) is there is not delta V then the work would equal zero as work is dependent on the volume of a system changing!
- Tue Feb 16, 2021 10:19 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Delta U
- Replies: 3
- Views: 202
Re: Delta U
Hi:)
delta H is apart of delta U. delta U is the entire change of internal energy of a system/ heat transfer of the system whereas delta H represents the change in enthalpy. Delta U is more overarching of the WHOLE system
delta H is apart of delta U. delta U is the entire change of internal energy of a system/ heat transfer of the system whereas delta H represents the change in enthalpy. Delta U is more overarching of the WHOLE system
- Tue Feb 16, 2021 10:09 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Values for Cv and Cp
- Replies: 3
- Views: 209
Re: Values for Cv and Cp
I do not think that you will be expected to memorize those values, but with anything it wouldn't hurt to know! Cv is usually given from my experience:)
- Tue Feb 16, 2021 10:04 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneity of a System
- Replies: 38
- Views: 2641
Re: Spontaneity of a System
https://courses.lumenlearning.com/suny-introductory-chemistry/chapter/spontaneity-free-energy-and-temperature/
This chart really helped me understand:) the big picture is just understanding when the gibbs free energy will be negative(neg=spontaneous)
This chart really helped me understand:) the big picture is just understanding when the gibbs free energy will be negative(neg=spontaneous)
- Thu Feb 11, 2021 6:02 pm
- Forum: Calculating Work of Expansion
- Topic: How to know which equations to use?
- Replies: 11
- Views: 721
Re: How to know which equations to use?
I would first look at what you've been given in the question, what are their units, and what units you need for the answer.
Once you've looked at what you have, try to determine what equations could apply(look at their constants and units necessary)
Hope this helps:)
Once you've looked at what you have, try to determine what equations could apply(look at their constants and units necessary)
Hope this helps:)
- Thu Feb 11, 2021 5:51 pm
- Forum: Calculating Work of Expansion
- Topic: Work
- Replies: 6
- Views: 332
Re: Work
I would just try to remember that work for REVERSIBLE>>>> work IRREVERSIBLE. But while irreversible is faster, it is also less efficient.
Hope this helps:)
Hope this helps:)
- Thu Feb 11, 2021 5:42 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Cv and Cp
- Replies: 2
- Views: 179
Re: Cv and Cp
Use the equation: Cp-Cv=R
hope this helps:)
hope this helps:)
- Thu Feb 11, 2021 5:41 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: deltaS equations
- Replies: 8
- Views: 310
Re: deltaS equations
deltaS = q/T for when there is a constant temperature
deltaS = nR*ln(V2/V1) for when there is a change in volume
deltaS = nC*ln(T2/T1) for when there is a change in temp
and remember that Cp-Cv= R
this basically summarizes the last two comments, hopefully this helps:)
deltaS = nR*ln(V2/V1) for when there is a change in volume
deltaS = nC*ln(T2/T1) for when there is a change in temp
and remember that Cp-Cv= R
this basically summarizes the last two comments, hopefully this helps:)
- Thu Feb 11, 2021 5:30 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Sapling #3 weeks 5/6
- Replies: 3
- Views: 172
Re: Sapling #3 weeks 5/6
For changes in entropy think about how much space the molecules will occupy after the phase change compared to the original phase.
For changes in enthalpy think about whether the reaction occurs spontaneously or requires heat to occur.
Hope this helps:)
For changes in enthalpy think about whether the reaction occurs spontaneously or requires heat to occur.
Hope this helps:)
- Thu Feb 04, 2021 5:05 pm
- Forum: Calculating Work of Expansion
- Topic: Work on surrounding
- Replies: 12
- Views: 391
Re: Work on surrounding
Just look at the GAS molecules when considering the work for this problem:) if there is a net increase of moles of gas on the product side then work is done on the surroundings.
- Thu Feb 04, 2021 5:02 pm
- Forum: Calculating Work of Expansion
- Topic: Work notation
- Replies: 10
- Views: 382
Re: Work notation
I denote work as a lowercase "w" :)
- Thu Feb 04, 2021 5:01 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: W
- Replies: 14
- Views: 492
Re: W
The "n" represents the 2 state system, and there are 4 molecules of CO... so you will have N^4 :)
- Thu Feb 04, 2021 4:56 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Strong acids/bases
- Replies: 10
- Views: 513
Re: Strong acids/bases
I just know the one for acids:
so - sulfuric acid
I - HI
brought -HBr
no - nitric acid
clean - HCl
clothes- perchloric acid
and that, like summer said, the group 1 and 2 elements form strong bases:)
so - sulfuric acid
I - HI
brought -HBr
no - nitric acid
clean - HCl
clothes- perchloric acid
and that, like summer said, the group 1 and 2 elements form strong bases:)
- Thu Feb 04, 2021 4:52 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Work
- Replies: 39
- Views: 1356
Re: Work
If the system does work than the work is negative, but if work is done on the system than that work is positive:) so if there is a larger negative kJ then that system did a larger amount of work .
- Thu Jan 28, 2021 6:16 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Polyprotic acids and bases
- Replies: 2
- Views: 187
Re: Polyprotic acids and bases
As Hila said above, Lavelle should let us know when KA2 is significant. Otherwise I would assume that only one deprotonization is significant:)
- Thu Jan 28, 2021 6:14 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Problem 6C.7 Help
- Replies: 3
- Views: 81
Re: Problem 6C.7 Help
When you are unable to find a molecule on the KA chart, start to look for its conjugate base in the KB chart and from there remember that KW=KAxKB. Hope this helps:)
- Thu Jan 28, 2021 6:13 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Textbook Problem 4E.9
- Replies: 3
- Views: 187
Re: Textbook Problem 4E.9
Look at the difference in bond stability for the resonance structures(eg double bond kj vs single bond kj):) the structure with the smallest energy I would assume to be the more stable structure!
- Thu Jan 28, 2021 6:10 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Significant Figures when Doing Ice Table Problems
- Replies: 3
- Views: 139
Re: Significant Figures when Doing Ice Table Problems
I wouldn't worry about sig figs too much:) with the test being multiple choice and Lavelle never putting any emphasis on sig figs I would just round as you normally do and if you did the calculations correctly there should be an answer very similar if not the same available:)
- Thu Jan 28, 2021 6:08 pm
- Forum: Phase Changes & Related Calculations
- Topic: reaction shifts
- Replies: 18
- Views: 608
Re: reaction shifts
In exothermic reactions, when heat is added the reactants will be favored just because the reaction releases energy when products are formed, so it doesn't need more heat. In endothermic reactions, an increase in heat will favor the products bc these reactions require heat as an energy source, so mo...
- Thu Jan 21, 2021 7:46 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Ka correlation to strength of an acid
- Replies: 30
- Views: 2047
Re: Ka correlation to strength of an acid
The larger the Ka the stronger the acid, and conversely, the larger the pKa the weaker the acid:)
- Thu Jan 21, 2021 7:43 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Equilibrium Adjustments
- Replies: 10
- Views: 386
Re: Equilibrium Adjustments
When a system is disturbed, it will do whatever possible to bring it back to equilibrium whether that be favoring the products or reactants etc. Basically the reaction wants to be balanced again:)
- Thu Jan 21, 2021 7:15 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5.I.35
- Replies: 2
- Views: 161
Re: 5.I.35
The first thing I always do when I see partial pressure is attempt to make an ICE box:) so set it up with:
1 0 0
-2p +p +p
1-2p p p
and then put products over reactants:
(p^2)/(1-2p)^2
Hopefully this is helpful!
1 0 0
-2p +p +p
1-2p p p
and then put products over reactants:
(p^2)/(1-2p)^2
Hopefully this is helpful!
- Thu Jan 21, 2021 7:09 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: textbook 6.A.19
- Replies: 4
- Views: 210
Re: textbook 6.A.19
I would plug it into the KW=[H30+][OH-] equation, but I am not exactly sure if this equation is relevant just because I believe the solution has to be water during the ionization:) let me know how it goes!!
- Thu Jan 21, 2021 7:03 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Percent protonated vs percent ionization
- Replies: 6
- Views: 238
Re: Percent protonated vs percent ionization
I would assume that the calculations would be the same but it is just whether the chemical equation is talking about a acid(ionization) or a base(protonation) as the reactant:)
- Thu Jan 14, 2021 8:20 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Neglecting Water
- Replies: 20
- Views: 957
Re: Neglecting Water
I was confused by this at first too! Basically it is just that because there is so much water as the solvent the concentration of the water barely changes, enough to ignore it! So that is why we consider this change of [H2O] as negligible:)
- Thu Jan 14, 2021 7:57 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: adding heat
- Replies: 15
- Views: 458
Re: adding heat
Endothermic reactions require heat to occur so if you makes the surrounding environment hotter, the reaction will become favored and create more product:)
- Thu Jan 14, 2021 7:34 pm
- Forum: General Science Questions
- Topic: Charge sign in front of molecular formula meaning?
- Replies: 4
- Views: 259
Re: Charge sign in front of molecular formula meaning?
That is a really good question... hmm I'm either thinking that is represents the formal charge on the whole molecule or the charge on the element it is directly next to(ex "N").
- Thu Jan 14, 2021 7:19 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Difference between kA and kB
- Replies: 8
- Views: 283
Re: Difference between kA and kB
Hi:) to determine the difference you need to be able to identify the reactant as either an acid or base. If the reactant is an acid use Ka and if it is a base use Kb. Hope this is helpful:)
- Thu Jan 14, 2021 7:07 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pKa and pH
- Replies: 10
- Views: 532
Re: pKa and pH
I can totally see how they can seem very similar! But to think about their difference just remember that pH refers to the -log[H3O+] and pKA refers to the -log [H3O+][conj base]/[acid]. So basically pH is just taking into account the hydronium concentration.
- Fri Jan 08, 2021 11:20 pm
- Forum: Ideal Gases
- Topic: Ideal Gas Definition
- Replies: 10
- Views: 584
Re: Ideal Gas Definition
I wouldn't worry too much about the differences between ideal and non-ideal gases because I think in this class we are going to assume all gases we use in calculations will be relevant to PV=nRT. But this seems like a great video if you are looking for a deep explanation: https://www.khanacademy.org...
- Fri Jan 08, 2021 11:16 pm
- Forum: Ideal Gases
- Topic: Kc vs Kp
- Replies: 109
- Views: 4274
Re: Kc vs Kp
To me Kc makes the most sense so I would tend to use it, but when a problem dealing with gases explicitly gives you partial pressures(atm) us Kp:)
- Fri Jan 08, 2021 10:47 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Increasing the Volume
- Replies: 5
- Views: 138
Re: Increasing the Volume
Yes you are exactly correct:) reversing the situation(increasing the volume and decreasing the pressure) would turn the reaction to favors the side with a high mole count to balance back out!
- Fri Jan 08, 2021 10:41 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Confusion with terms
- Replies: 9
- Views: 325
Re: Confusion with terms
I would definitely try to use the term favors instead of shifting because it can get a little bit confusing in term of us explaining an equilibrium. And remember as well that when Q<K the products are favored and when Q>K the reactants are favored:)
- Fri Jan 08, 2021 10:39 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Calculator Trick for ICEbox Calculations
- Replies: 13
- Views: 684
Re: Calculator Trick for ICEbox Calculations
This is a great way to find the y intercepts of the found quadratic equation! Thank you so much! And remember to use the POSITIVE x intercept because concentration is always positive:)
- Fri Dec 11, 2020 9:32 am
- Forum: Properties of Light
- Topic: What are the ranges of wavelength for each type of electromagnetic radiation?
- Replies: 5
- Views: 365
Re: What are the ranges of wavelength for each type of electromagnetic radiation?
For the final I would recommend knowing the order on the spectrum and that visible is light is 400-700nm. and know that the lyman series is apart of the UV spectrum and the balmer series is apart of the visible light spectrum:)
- Fri Dec 11, 2020 9:28 am
- Forum: Resonance Structures
- Topic: Resonance Hyrbid
- Replies: 11
- Views: 493
Re: Resonance Hyrbid
this is a bit of a dumb question but what exactly do we mean when we say something is delocalized? i've seen it in a couple of posts and im a bit confused as to what that exactly means When we are talking about delocalization, we are talking about the electrons being free to roam and not stuck on j...
- Fri Dec 11, 2020 9:16 am
- Forum: Polyprotic Acids & Bases
- Topic: Calculating Ka
- Replies: 9
- Views: 825
Re: Calculating Ka
You would use the molarities of the products and the reactants so to calculate KA you need to know the concentrations:)
- Fri Dec 11, 2020 9:12 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Calculating H+
- Replies: 17
- Views: 796
Re: Calculating H+
[H+] = 10^-pH and then once you have the pH, 14-pH=poH
Hope this helps:)
Hope this helps:)
- Fri Dec 11, 2020 9:10 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: H3O+ versus H+
- Replies: 19
- Views: 5086
Re: H3O+ versus H+
Dr. Lavelle suggests that we treat them both as the same thing:) so [H+] and [H30+] are the same!
- Sat Dec 05, 2020 7:12 pm
- Forum: Lewis Acids & Bases
- Topic: Bronsted vs. Lewis bases
- Replies: 11
- Views: 326
Re: Bronsted vs. Lewis bases
Yes! We look at bronsted and lewis bases in the same way but it is just the way they are described that differs. Lewis bases are describes in how they donate electrons and bronsted bases receive protons:)
- Sat Dec 05, 2020 7:10 pm
- Forum: Lewis Structures
- Topic: Most Stable Structure
- Replies: 23
- Views: 3361
Re: Most Stable Structure
The most stable/favorable structures are those with the lowest formal charge and can be found out by drawing the lewis structure:)
- Sat Dec 05, 2020 6:48 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: ligands
- Replies: 11
- Views: 431
Re: ligands
NH3 is a neutral molecule so it is in turn a neutral ligand. When in doubt draw the lewis structure and calculate the formal charges:)
- Sat Dec 05, 2020 6:44 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: pH Chart
- Replies: 16
- Views: 565
Re: pH Chart
I don't think that we have to remember the exact values for common compounds, but I would definitely not at least that water has a pH level of 7(neutral) and that acids are less than 7 and bases are above 7:)
- Sat Dec 05, 2020 6:40 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Tetrahedral v Square Planar
- Replies: 6
- Views: 277
Re: Tetrahedral v Square Planar
I would still go for either square planar or tetrahedral. We haven't really covered the extent to which to determine between them as far as I'm concerned so I wouldn't worry too much as of now:)
- Sun Nov 29, 2020 6:01 pm
- Forum: Ionic & Covalent Bonds
- Topic: Lewis structure
- Replies: 13
- Views: 588
Re: Lewis structure
The way I typically tell is by looking at the molecule and comparing the distance of the two atoms connected on the periodic table. Atoms close together on the periodic table are typically ionic, and those far away are typically covalent:)
- Sun Nov 29, 2020 5:45 pm
- Forum: Sigma & Pi Bonds
- Topic: pi bonds
- Replies: 16
- Views: 1007
Re: pi bonds
Pi bonds are formed laterally so that the molecules cannot rotate. Sigma bonds are formed at the tip so that rotation is allowed. Basically pi bonds make the molecules stuck in position:)
- Sun Nov 29, 2020 4:36 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Axial vs Equatorial Bonds
- Replies: 11
- Views: 2943
Re: Axial vs Equatorial Bonds
In terms of placements, axial bonds are in the vertical plane and equatorial bonds are on the lateral plane. Structures are most favorable when atoms/bonds are farthest away, so I would assume that bonds on the axial plane are preferential because the bond angle is 180 degrees(farthest possible).
- Sun Nov 29, 2020 3:29 pm
- Forum: Hybridization
- Topic: delocalized pi bonds
- Replies: 15
- Views: 519
Re: delocalized pi bonds
I would definitely recommend drawing out the lewis structure to see if there are possible resonance structures. If there are then you will have delocalized pi bonds. Better to be safe than sorry:)
- Sun Nov 29, 2020 3:27 pm
- Forum: Hybridization
- Topic: hybridization orbitals
- Replies: 5
- Views: 218
Re: hybridization orbitals
I first count the number of regions of electron density there are, and then pick the hybridization orbital with that corresponding number of regions. Because sp3 has 4 regions, it is the hybridization for an atom with 4 regions of electron density. And sp had 2 regions, so it must be from an atom wi...
- Sat Nov 21, 2020 3:53 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Importance of anions and cations
- Replies: 15
- Views: 1030
Re: Importance of anions and cations
I would for sure remember the difference between cations and anions. Cations are positively charged molecules/atoms and anions are negatively charged atoms/molecules. As well as most cations are lewis acids because they are likely to accept electrons and anions are likely lewis bases.
- Sat Nov 21, 2020 3:49 pm
- Forum: Lewis Structures
- Topic: Expanded Valence
- Replies: 6
- Views: 393
Re: Expanded Valence
To count the number of valence electrons, you would create the lewis structure for the molecule and count how many electrons are attached to the central atom:)
- Sat Nov 21, 2020 3:36 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent Character
- Replies: 14
- Views: 2179
Re: Covalent Character
To determine the extent of a molecules covalent character, we look at the atoms difference in electronegativities. If molecules have a very close electronegativity then they have a high covalent character. Difference in electronegativity<1.5= covalent.
- Sat Nov 21, 2020 3:29 pm
- Forum: Ionic & Covalent Bonds
- Topic: Molecule size and ionic character
- Replies: 13
- Views: 1274
Re: Molecule size and ionic character
To determine the ionic characterization of a molecule we look at the electronegativity between the atoms. The molecules with the highest electronegativity are those at the top right and lowest and the bottom left. So I would assume that the larger the size difference of the molecules, the more ionic.
- Sat Nov 21, 2020 3:22 pm
- Forum: Lewis Structures
- Topic: Identifying Lewis Acids and Bases
- Replies: 8
- Views: 406
Re: Identifying Lewis Acids and Bases
Lewis acids accept electrons and bases donate electrons. So when you so a molecules lewis structure and see it has lone pairs, it will likely be a base because it has donate them. Also the formal charge helps me decipher(negative=base, positive=acid).
- Sun Nov 15, 2020 2:15 pm
- Forum: Dipole Moments
- Topic: Electric Dipole Moment
- Replies: 3
- Views: 159
Re: Electric Dipole Moment
As far as the dipole moment, it is the measure of the electric polarity of charges in a molecule(the uneven distribution of charges among elements in a molecule). I am not sure how to calculate the magnitude of each charge, but if you know each charge you can multiply them and then divide by the dis...
- Sun Nov 15, 2020 2:09 pm
- Forum: Dipole Moments
- Topic: hydrogen bonding and ice
- Replies: 4
- Views: 153
Re: hydrogen bonding and ice
In ice, the water molecules stay together, and their bonds are then larger than those of the liquid water molecule(broken and unbroken simultaneously. So with the increased distance between molecules, the density is less causing it to float:)
- Sun Nov 15, 2020 2:07 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Writing Electron Configurations
- Replies: 9
- Views: 797
Re: Writing Electron Configurations
5s is the outermost shell in this situation and going to be the shell that the first couple electrons are going to be taken out of despite being first in the periodic table. In general, the NS2 shell electrons will be taken before the ND10.
- Sun Nov 15, 2020 1:59 pm
- Forum: Bond Lengths & Energies
- Topic: boiling point and IMS
- Replies: 5
- Views: 304
Re: boiling point and IMS
If a molecule has extremely strong intermolecular forces than it must have a high boiling point. The stronger the forces, the more energy needed to break apart the molecule(higher heat=higher energy).
- Sun Nov 15, 2020 1:56 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Strengths
- Replies: 10
- Views: 430
Re: Bond Strengths
I would agree with the others in that bond length plays a major role in determining the bond strength. In the same molecule, a single bond is less strong than a double, and a double weaker than a triple. Atom size also plays a prevalent role in that as atomic radius increases so does the ionization ...
- Thu Nov 05, 2020 11:43 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: ml and number of possible electrons
- Replies: 6
- Views: 185
Re: ml and number of possible electrons
Yes! If ml is specified but not ms that is because ms just refers to the spin of the electrons in a subshell. The spin can either be up or down so there are only two options for ms:)
- Thu Nov 05, 2020 11:40 pm
- Forum: Student Social/Study Group
- Topic: Studying Tips
- Replies: 23
- Views: 785
Re: Studying Tips
I definitely think just doing review problems is the best way to use your time! Getting your mind in the right "chemistry mode" is really helpful to me because honestly sometimes my brain can get pretty overwhelmed, but just taking my time through problems helps me find good strategies of ...
- Thu Nov 05, 2020 11:28 pm
- Forum: Lewis Structures
- Topic: Formal Charge
- Replies: 5
- Views: 136
Re: Formal Charge
The closer the formal charge to 0, the more stable. If the formal charge has a high negativity than the molecule is highly reactive.
- Thu Nov 05, 2020 11:15 pm
- Forum: Trends in The Periodic Table
- Topic: # of electrons
- Replies: 23
- Views: 606
Re: # of electrons
To find the number of electrons in an atom just look at its atomic number:) because the number of protons in an atom matches the number of electrons. To find the number of valence electrons in an atom just count across the period on the period table!
- Thu Nov 05, 2020 11:09 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Scores
- Replies: 28
- Views: 1077
Re: Midterm Scores
The midterm was posted today with our scores on CCLE in the grades section on the left hand side:) I was not able to look at the problems I missed but hopefully we will be able to whether that be in discussion or if Professor Lavelle releases the test.
- Thu Oct 29, 2020 9:22 pm
- Forum: Student Social/Study Group
- Topic: How to relax
- Replies: 168
- Views: 20344
Re: How to relax
oh my gosh thank you for putting up this question! It's so important to remember to relax and enjoy the journey however corny it sounds:) To relax I love going outside and backpacking. Even its just for a single overnighter trip, it lets me forget about all my stress and honestly just reminds me tha...
- Thu Oct 29, 2020 9:04 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic Radius
- Replies: 30
- Views: 2858
Re: Atomic Radius
The atomic radii will increase as you move down the group because electrons are being added to other shells, and the radii will decrease across a period as an increase in electrons will result in a higher nuclear charge pulling the electrons tighter towards the nucleus. Hope this helps:)
- Thu Oct 29, 2020 8:47 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: position units
- Replies: 19
- Views: 1272
Re: position units
I would for sure convert nm to m whenever you have to plug in values to equations. Because meters is an SI unit you must use it in equations to make sure of unit consistency:)
- Thu Oct 29, 2020 8:26 pm
- Forum: Properties of Light
- Topic: Is c always the speed of light?
- Replies: 92
- Views: 4750
Re: Is c always the speed of light?
C is a constant in the equation such as "h"=6.626*10^-34. So I would continue using the constant as 3*10^8 for the purposes of our use. But as far as momentum equation(p=mv) the velocity changes.
- Thu Oct 29, 2020 8:15 pm
- Forum: Student Social/Study Group
- Topic: Midterm Grades
- Replies: 5
- Views: 276
Re: Midterm Grades
Once the last discussion section has completed it the scores will be released I think:) hopefully after we will discuss the questions and get a better understanding of them too!
- Thu Oct 22, 2020 10:23 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: textbook 1A.3
- Replies: 4
- Views: 194
Re: textbook 1A.3
I am not sure if my answer is correct but I am leaning toward "A". Because frequency("v") is related to the speed("c") in the equation c=h*v a decrease in the frequency would result in a decrease in the speed of the radiation. But I am not 100% so if someone could doubl...
- Thu Oct 22, 2020 10:20 am
- Forum: Administrative Questions and Class Announcements
- Topic: Scratch Paper for Midterm
- Replies: 2
- Views: 179
Re: Scratch Paper for Midterm
My TA said that we would be able to use our calculators, formula sheet, periodic table, and scratch paper so I'm assuming that we can get an additional piece of paper. But I'm thinking that they may want to check the front and back of our own scratch paper before we start the exam. Hopefully this is...
- Thu Oct 22, 2020 10:18 am
- Forum: Balancing Chemical Reactions
- Topic: Formula Unit vs. Molecules
- Replies: 3
- Views: 1077
Re: Formula Unit vs. Molecules
I think that NaOH is referred to as a formula unit because of its type of bonding(ionic), and similarly H2O is referred to as a molecule because of its molecular bonds. Hope this is helpful:)
- Thu Oct 22, 2020 10:16 am
- Forum: Properties of Electrons
- Topic: intensity vs energy
- Replies: 29
- Views: 3115
Re: intensity vs energy
This statement is FALSE. An increase in intensity will lead to an increase in the number of photons emitted and therefore an increase in the number of electrons affected(1 photon: 1 electron). But the number of electrons affected will not contribute to the total amount of energy, as frequency is the...
- Thu Oct 22, 2020 10:11 am
- Forum: Properties of Light
- Topic: Frequency and Wavelength on Light Spectrum
- Replies: 5
- Views: 237
Re: Frequency and Wavelength on Light Spectrum
My TA was telling us that learning too much about the electromagnetic spectrum would definitely be better than the alternative. We won't be given a guide to the EM spectrum so at look getting a rough idea of wavelength and their corresponding regions would be really beneficial. And knowing the wavel...
- Wed Oct 14, 2020 10:40 pm
- Forum: Einstein Equation
- Topic: m vs nm
- Replies: 66
- Views: 3210
Re: m vs nm
The SI unit for length is meters so when in doubt I would go with that! But in an example problem during lecture, Professor said that both meters and nanometers are acceptable. Unless explicitly specified or needed for specific conversion factors both should work:)
- Wed Oct 14, 2020 10:34 pm
- Forum: Properties of Light
- Topic: Amplitude and Energy
- Replies: 6
- Views: 200
Re: Amplitude and Energy
Yes amplitude is related to the intensity of the light/photons. The higher the intensity, the more photons affected! But in terms of creating energy to release electrons in the photoelectric effect, increasing amplitude does not increase the likelihood of release:) hope this helps!
- Wed Oct 14, 2020 10:32 pm
- Forum: Photoelectric Effect
- Topic: Excess energy
- Replies: 20
- Views: 537
Re: Excess energy
1/2 mv^2 is the kinetic energy/excess energy of the electron. If the energy to release an electron is less than the energy of the photon, you will be left with kinetic energy that can be calculated with the speed of the electron giving off:)
- Wed Oct 14, 2020 10:30 pm
- Forum: Photoelectric Effect
- Topic: Amplitude and Intensity
- Replies: 6
- Views: 237
Re: Amplitude and Intensity
Yep you got it! Like professor was talking about, if you increase the number of runners but no one has enough energy to get over the hurdles you will not get anywhere. If you want a photon/runner to get over the hurdle/release an electron you must increase the frequency not the wavelength:)
- Wed Oct 14, 2020 10:24 pm
- Forum: Properties of Light
- Topic: Balmer vs Lyman
- Replies: 12
- Views: 395
Re: Balmer vs Lyman
Most electrons in the Balmer series start at n=3 and go to n=2. The most important aspect of the Lyman series is that there is a much greater energy release as the electron goes from n=2 to n=1, and the "jump" is much larger than from 3 to 2. As the electron levels go higher, the levels be...
- Tue Oct 06, 2020 9:17 pm
- Forum: Student Social/Study Group
- Topic: Zoom Lectures
- Replies: 11
- Views: 296
Re: Zoom Lectures
I asked my TA today that same question, and as far as she knows the lectures will continue to be asynchronous unless explicitly expressed otherwise. But the discussions and office hours will offer the live interaction if you want it!
- Tue Oct 06, 2020 9:08 pm
- Forum: Balancing Chemical Reactions
- Topic: Week 1 Sapling #10 Balancing Reaction
- Replies: 7
- Views: 186
Re: Week 1 Sapling #10 Balancing Reaction
I just completed that question! For this one assume that the equation is balanced and the ratio of the molecules is 1:1. No balancing needed:)
- Tue Oct 06, 2020 9:05 pm
- Forum: Limiting Reactant Calculations
- Topic: maximum amount of products
- Replies: 4
- Views: 974
Re: maximum amount of products
If only 1 mole of A is present than you know that the product will have half of the moles it would if you had the 2 moles requires(you only have 1/2 moles of A-> .5). And because you need the same number of moles on the left side(3 moles if you were to have the 1 mole of b and 2 of a), you take half...
- Tue Oct 06, 2020 8:59 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Moles produced
- Replies: 3
- Views: 119
Re: Moles produced
To start this problem I would calculate how many moles of CaCO3 are produced from the 1 Kg. And knowing that the ratio of CO2 to CaCO3 is 1:1 you know that the moles will be the same for both molecules. Hopefully this is right and helps you out:)
- Tue Oct 06, 2020 8:52 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Avogadro's #
- Replies: 33
- Views: 3860
Re: Avogadro's #
The most common times I've used Avogadro's number is when I am finding the number of molecules and converting molecules of elements to moles. In one mole there are 6.022e23 particles/molecules so if you know how many moles of an element there are, then you can determine the number of particles. ex: ...