Search found 106 matches

by Diana A 2L
Tue Mar 17, 2020 10:45 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: ΔGionization
Replies: 8
Views: 124

Re: ΔGionization

Ellen Amico 2L wrote:Nope! you can use any of the equations for calculating deltaG. I think it's just a way to label it relating to the reaction.


Thank you! I understand now:)
by Diana A 2L
Tue Mar 17, 2020 10:44 pm
Forum: Student Social/Study Group
Topic: Coronavirus Joke
Replies: 14
Views: 528

Re: Coronavirus Joke

005290099 wrote:Got a corona virus pickup line for all you players out there:

You can't spell quarantine without u, r, a, q, t ;)


THIS WAS A GOOD ONE. THANK YOU.
by Diana A 2L
Mon Mar 16, 2020 8:57 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Lewis structures
Replies: 4
Views: 62

Re: Lewis structures

You would calculate the enthalpies of formation of the substances, and then subtract the enthalpy of the reactants from the enthalpy of the products to see if you get a positive or negative value. Negative, it'll be exothermic, positive endothermic.
by Diana A 2L
Mon Mar 16, 2020 8:49 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: reverse half reaction
Replies: 4
Views: 78

Re: reverse half reaction

In that case, does that mean cell potentials are calculated first, only using the standard reduction potentials? Like, you calculate cell potential before flipping the equation that is oxidized? Right?
by Diana A 2L
Mon Mar 16, 2020 8:43 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Concentration Cells
Replies: 8
Views: 98

Re: Concentration Cells

The standard cell potential is dependent on how different the concentrations in each of the half-cells are, as that is what generates the potential difference that allows a reaction to proceed in a certain direction. Standard cell potential is zero when the concentrations are the same because the re...
by Diana A 2L
Mon Mar 16, 2020 8:34 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: Reverse rate Laws
Replies: 3
Views: 51

Re: Reverse rate Laws

^ Yes, also, the overall rate is equal to the forward K / reverse K, so to find the reverse k, you'd have to solve K(reverse)=K(forward)/K(overall).
by Diana A 2L
Mon Mar 16, 2020 8:26 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: ΔGionization
Replies: 8
Views: 124

Re: ΔGionization

Tauhid Islam- 1H wrote:I'm pretty sure all standard state quantities are dependent on time. Gibb's free energy change is a function of temperature so at different temperatures, you would have different energies.


In that case, how would you calculate Gibbs Free Energy at non-standard temperature?
by Diana A 2L
Mon Mar 16, 2020 1:12 am
Forum: Student Social/Study Group
Topic: Mental Health
Replies: 2
Views: 137

Mental Health

Yall please remember to take care of yourselves, as much as physical health is SO important right now with the corona, don't forget to take care of your mental health. If you ever feel stressed and overwhelmed about the chaos that is 2020, just remember, a wise prophet once said: "It really jus...
by Diana A 2L
Mon Mar 16, 2020 1:04 am
Forum: Student Social/Study Group
Topic: Farewell to you all
Replies: 1
Views: 72

Farewell to you all

As the winter quarter comes to a close, I want to congratulate everyone for making it this far. We got through seasonal depression, Kobe's/Gigi's deaths, UCLA's closure and transition to online, and the coronavirus panic over toilet paper. WEVE BEEN THROUGH A LOT THIS YEAR, AND ITS ONLY BEEN 2.5 MON...
by Diana A 2L
Mon Mar 16, 2020 12:48 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Activation Energy
Replies: 3
Views: 57

Re: Activation Energy

Does this mean that free energy of activation measured without the enzyme? Or is it needed in relation to the activation energy with the enzyme? Not exactly. It means that the free energy of activation is the, let's say, "left over" energy of activation in addition to the activation energ...
by Diana A 2L
Mon Mar 16, 2020 12:38 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: ΔGionization
Replies: 8
Views: 124

Re: ΔGionization

Would delta G ionization be the same for other temperatures besides 25 degrees Celsius? Let's say for example you're taking the delta G of ionization for a reaction at 30 degrees Celsius, would you use just the standard equations for delta G? I hope that question makes sense, please someone help I w...
by Diana A 2L
Mon Mar 16, 2020 12:12 am
Forum: Student Social/Study Group
Topic: Coronavirus Joke
Replies: 14
Views: 528

Re: Coronavirus Joke

I'm glad you guys liked the meme!
by Diana A 2L
Mon Mar 16, 2020 12:08 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Delta U
Replies: 4
Views: 79

Re: Delta U

Also, if heat is released, q is negative, and if it's absorbed, q is positive. Then you use the delta U= q+w equation to determine if overall internal energy is positive or negative.
by Diana A 2L
Mon Mar 16, 2020 12:06 am
Forum: Balancing Redox Reactions
Topic: Ecell values
Replies: 12
Views: 132

Re: Ecell values

If you take the reverse of a reaction, does the sign of the Ecell also flip, or does it remain? For example, when constructing redox reactions from redox couples you are given, you determine which couple is at the anode and at the cathode by examining Ecell values. You set up the reaction in a way t...
by Diana A 2L
Fri Mar 13, 2020 7:34 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Activation Energy
Replies: 3
Views: 57

Re: Activation Energy

Free energy of activation is Gibbs free energy. This is referred to in terms of the energy barrier of a chemical reaction. Activation energy is the energy needed to surpass the barrier of the transition steps of a reaction. The energy of activation is also the difference in energy between the (trans...
by Diana A 2L
Fri Mar 13, 2020 7:15 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Pressure, Volume
Replies: 5
Views: 90

Re: Pressure, Volume

well we know the ideal gas law inversely relates pressure with volume, pv=nRT, meaning as one increases the other decreases. I haven't seen it being related to le chateliers principle however. Pressure is literally directly related to Le chateliers. Just like a change in volume or concentration aff...
by Diana A 2L
Fri Mar 13, 2020 6:59 pm
Forum: Student Social/Study Group
Topic: Coronavirus Joke
Replies: 14
Views: 528

Coronavirus Joke

Just to lighten the mood and destress:) This one made me laugh out loud.
by Diana A 2L
Fri Mar 13, 2020 6:43 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: relationship to cell potential
Replies: 2
Views: 55

Re: relationship to cell potential

Kaylee Clarke 1G wrote:how would you explain the relationship between cell potential and work in words? and, for cell potential and free energy?


I actually answered a similar question earlier, here’s the link:

viewtopic.php?f=141&t=62264

Hope that helps!
by Diana A 2L
Fri Mar 13, 2020 6:37 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: electrochemical series
Replies: 4
Views: 71

Re: electrochemical series

The electrochemical series is a table of the relative strengths of oxidizing and reducing agents. It shows the oxidizing and reducing power of redox couples, with the strongest oxidizing agents on the top left and strongest reducing agents at the bottom right. Knowing oxidizing and reducing power he...
by Diana A 2L
Fri Mar 13, 2020 6:20 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Relationship between work, cell potential, and delta G
Replies: 6
Views: 108

Re: Relationship between work, cell potential, and delta G

When delta G is negative, there is energy free to do work. Cell potential wants to go down. IF cell potential goes down there is a release of energy free to do work. I don’t think this is a correct. In the equation delta G= -nFEcell, if cell potential is higher, and more positive, then Gibbs free e...
by Diana A 2L
Fri Mar 13, 2020 5:33 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: relationship between entropy and enthalpy
Replies: 2
Views: 56

Re: relationship between entropy and enthalpy

There isn’t a DIRECT relationship between entropy and enthalpy, BUT Gibbs free energy provides a relationship between both terms in the equation: delta G = delta H — T(delta S). For a system where delta G= 0, then delta S= delta H/ T , in which case there is a direct relationship.
by Diana A 2L
Fri Mar 13, 2020 3:16 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Slow step
Replies: 7
Views: 80

Re: Slow step

Kayla Maldonado 1C wrote:
Abby Soriano 1J wrote:The problem will most likely specify which of the steps is the slow step. You will probably be asked if a proposed mechanism matches the observed rate law, but you won't need to actually calculate a value for the slow step.

If the rate matches the observed rate law is that the slowest step?


Yes.
by Diana A 2L
Fri Mar 13, 2020 3:01 pm
Forum: Balancing Redox Reactions
Topic: redox of chlorine in water 6K.3 d
Replies: 2
Views: 25

Re: redox of chlorine in water 6K.3 d

Cl 2 (g) \rightarrow HClO(aq) + Cl 2 (g). I don't know how to find the reduction half of this problem, it shows Cl going to Cl which isn't a loss or gain of electrons. I do believe that there is a typo in the book. The Cl2(g) on the product side should be Cl- In that case, the reduction would be fr...
by Diana A 2L
Fri Mar 13, 2020 2:51 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Slow step
Replies: 7
Views: 80

Re: Slow step

^^^ Yes. “Slowness” is relative to the reaction mechanism.
by Diana A 2L
Fri Mar 13, 2020 2:40 pm
Forum: Zero Order Reactions
Topic: catalyst
Replies: 5
Views: 75

Re: catalyst

Here’s a link to offer a more detailed explanation!


https://chem.libretexts.org/Core/Physic ... _Reactions
by Diana A 2L
Fri Mar 13, 2020 2:29 pm
Forum: Zero Order Reactions
Topic: catalyst
Replies: 5
Views: 75

Re: catalyst

No, not all zero order reactions is dependent on a catalyst. A zero order reaction could also occur with an enzyme or a surface. It's just that most commonly you would find a catalyst with a zero order reaction. Aren't enzymes just biological catalysts? AHHH yes they are! Let me provide a better an...
by Diana A 2L
Fri Mar 13, 2020 2:08 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Pressure, Volume
Replies: 5
Views: 90

Re: Pressure, Volume

Sorry I meant a pressure change for one of the reactants or products. I can’t think of any case in which this will happen. In order to change the pressure for a SPECIFIC reactant or product without changing the pressure of the whole system, that reactant or product would have to be isolated. And in...
by Diana A 2L
Fri Mar 13, 2020 2:00 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: deltaG at equilibrium
Replies: 8
Views: 131

Re: deltaG at equilibrium

I thought that delta G naught, was just at standard conditions not equilibrium? You’re right the difference is that delta G naught is at standard conditions. Delta G naught is always the same because it is referring to when the reactant/products are at standard conditions. Would that mean standard ...
by Diana A 2L
Fri Mar 13, 2020 1:41 pm
Forum: General Rate Laws
Topic: Determining a rate law graphically
Replies: 1
Views: 26

Re: Determining a rate law graphically

Is it possible to determine a rate law from a tangent line or a secant line of a graph of time in seconds vs concentrations? Essentially you can, but there will be an error bound for the value you find. The only point at which the rate will truly be accurate using a tangent or secant line will be a...
by Diana A 2L
Fri Mar 13, 2020 1:33 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pressure and Molarity
Replies: 3
Views: 74

Re: Pressure and Molarity

You just use the Molarity Values and find K based on concentration. You use whatever you’re given to find K. If given pressure, use pressure. If given concentration, use concentration. Don’t over-complicate it! Good luck!!
by Diana A 2L
Fri Mar 13, 2020 1:31 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Pressure, Volume
Replies: 5
Views: 90

Re: Pressure, Volume

Can someone explain the relationship between pressure, volume, and le chatelier? Like what if both sides of the equation have equal numbers of moles, how will a pressure change affect that? So if the number of moles is the same, a pressure change won’t affect the equilibrium. Since the pressure wil...
by Diana A 2L
Fri Mar 13, 2020 1:27 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: test 2 #6 steps
Replies: 4
Views: 52

Re: test 2 #6 steps

Can someone please explain the math steps involved to get the correct answer for this problem? I understand the set up, just not the steps you need to take to get the right answer of 0.42M. Thank you! Well first you’d multiply both sides by -2/0.0257 ( the reciprocal of the constant on the left sid...
by Diana A 2L
Fri Mar 13, 2020 1:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: equilibrium review
Replies: 1
Views: 81

Re: equilibrium review

Could someone help me with number 4 on the UA first review sheet? I am a bit confused as to where to even start with this problem. Q4. The overall dissociation of oxalic acid, H2C2O4 is represented below. The overall dissociation constant is also indicated. a) What volume of 0.400 M NaOH is require...
by Diana A 2L
Fri Mar 13, 2020 12:53 pm
Forum: Phase Changes & Related Calculations
Topic: Steam vs Boiling water
Replies: 2
Views: 68

Re: Steam vs Boiling water

Why is steam a worse burn? is it because it still has higher energy than boiling water at the same temp? Well, steam has a higher energy at 100°C. Let’s visualize. Energy in boiling water is the energy water gained until heating at 100 degrees Celsius to boil. The energy in steam is the energy it g...
by Diana A 2L
Fri Mar 13, 2020 12:45 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Relationship between work, cell potential, and delta G
Replies: 6
Views: 108

Re: Relationship between work, cell potential, and delta G

Can someone please explain (conceptually, not with equations) the relationship between work, cell potential, and delta G? Like explain why wmax is = to delta G. So when delta G is negative, this implies spontaneity (a reaction natural wants to occur in that direction). This means that the reaction ...
by Diana A 2L
Fri Mar 13, 2020 12:35 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Using kJ/mol vs. kJ
Replies: 2
Views: 63

Re: Using kJ/mol vs. kJ

Do we only use kJ/mol if we have been given the value or calculated a reaction with only one mole of a particular reactant? You use KJ/mol for standard values like standard enthalpy of formation or standard Gibbs free energy because standard conditions are ones for 1 mol of a substance. This is any...
by Diana A 2L
Fri Mar 13, 2020 12:32 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Slow Step Determination
Replies: 5
Views: 48

Re: Slow Step Determination

How do we determine which step is slow? Or will this always be given? It should be given usually, in the case that it’s not (which could happen), you would pretend every step is the slow one and then find the rate law and check if it matches the overall rate law. Whichever one ends up matching, tha...
by Diana A 2L
Fri Mar 13, 2020 12:16 pm
Forum: First Order Reactions
Topic: 7A.7bc
Replies: 1
Views: 20

Re: 7A.7bc

7A.7 Express the units for rate constants when the concentrations are in moles per liter and time is in seconds for (a) zeroth-order reactions; (b) first-order reactions; (c) second-order reactions. Why do you divide by mol/L for first and second order reactions? The rate of a reaction is usually g...
by Diana A 2L
Fri Mar 13, 2020 12:09 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: A- pre-exponential factor
Replies: 2
Views: 29

Re: A- pre-exponential factor

Using the Arrenhius equation, take the natural log. Then you get ln k =-Ea/R (1/T) + ln A. From here, exponentiate, then divide to solve for A. You get A= k/ (e^-Ea/RT), Now to calculate A, you need to know R, T, Ea, and k. We know R, we probably know T, and k, even if it’s not already given, you ca...
by Diana A 2L
Fri Mar 13, 2020 12:00 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Reaction Rate
Replies: 2
Views: 19

Re: Reaction Rate

Are reaction rates only determined by the reactants of the slow step? The reaction rate is determined by the RATE of the slow step, not its reactants. And not all reactions have rate-determining steps. Also, reaction rates are determined by the rate of the slow step only for reaction mechanisms I b...
by Diana A 2L
Fri Mar 13, 2020 11:54 am
Forum: General Rate Laws
Topic: Average rate vs unique rate
Replies: 4
Views: 45

Re: Average rate vs unique rate

How do you know when to use the average rate vs the unique rate? Unique rates are used when you’re referring to a specific reactant or product, and it’s the rate of disappearance or appearance of a substance divided by the stoichiometric coefficient, which is why it’s so specific. When you calculat...
by Diana A 2L
Fri Mar 13, 2020 11:40 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Arrhenius equation
Replies: 1
Views: 23

Re: Arrhenius equation

When you're modeling a reaction using the Arrhenius theory, why will the plot be linear? This is because taking the natural log of the Arrhenius equation yields: ln k = ln A - Ea/R(1/T). Then rearranging that gives: ln k = -Ea/R(1/T) + ln A. This equation has the linear form of y=Mx +b. When a reac...
by Diana A 2L
Fri Mar 13, 2020 11:20 am
Forum: General Rate Laws
Topic: Temperature and kinetics
Replies: 5
Views: 43

Re: Temperature and kinetics

Yes. At higher temperatures, molecules move faster and bump into each other more, so essentially kinetic energy will be higher.
by Diana A 2L
Fri Mar 13, 2020 11:18 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: deltaG at equilibrium
Replies: 8
Views: 131

Re: deltaG at equilibrium

Yes, because of the equation: delta(G) = delta(G0) + RTln(Q) and since we are at equilibrium, Q=K as well as delta(G0) = -RTln(K). So if you plug things back in, you get delta(G) = -RTln(K) + RTln(K) which equals 0 I thought that delta G naught, was just at standard conditions not equilibrium? You’...
by Diana A 2L
Thu Mar 12, 2020 9:46 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Review Problem for Week 10 #5
Replies: 3
Views: 69

Re: Review Problem for Week 10 #5

You should generally know the molecules for which delta G of formation is zero (the same molecules for which delta H of formation is zero at their standard states).
by Diana A 2L
Thu Mar 12, 2020 9:04 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Topics
Replies: 10
Views: 85

Re: Final Topics

Will concepts of electrolysis (6O) and the process of the corrosion of iron (6N.4) need to be known for the exam?
by Diana A 2L
Thu Mar 12, 2020 8:30 pm
Forum: General Rate Laws
Topic: Instantaneous and Average Rate
Replies: 3
Views: 28

Re: Instantaneous and Average Rate

Will average rate and instantaneous rate be the same for a reaction already at equilibrium?
by Diana A 2L
Tue Feb 11, 2020 3:34 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Test Material [ENDORSED]
Replies: 1
Views: 56

Test Material [ENDORSED]

For the midterm, do we have to know the equipartition theorem and the contribution to internal energy by translational and rotational energies of particles? This is topic 4B.3, which was in the list of readings for the chapter. Not specified if we must know this or not. Thank you.
by Diana A 2L
Mon Feb 03, 2020 12:03 am
Forum: Calculating Work of Expansion
Topic: Midterm Question Involving Integrals
Replies: 3
Views: 37

Midterm Question Involving Integrals

Is it likely that we will receive an exam question that will require us to actually integrate or apply legitimate math concepts? Is it viable to just memorize the regular and integrated form of the expansion equations, and use appropriate cases? Also, will the work of expansion equations with the in...
by Diana A 2L
Mon Feb 03, 2020 12:00 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Work done BY vs work done ON
Replies: 9
Views: 75

Re: Work done BY vs work done ON

For the thermodynamic equations used in this class, aren’t most of them constructed in a way that regards work being done BY a system? For example, there’s a negative sign on the work equation to make sure the work value ends up negative since energy is lost from a system when work is done by it. I ...
by Diana A 2L
Sun Feb 02, 2020 11:58 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible Reactions
Replies: 5
Views: 40

Re: Reversible Reactions

I have a question related to lecture material. Are systems at constant pressure synonymous to systems to which energy changes occur that are reversible? In lecture, there was some sort of association drawn between constant pressure and reversible reactions and I want to confirm if I understood it co...
by Diana A 2L
Sun Feb 02, 2020 11:53 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Extensive vs. intensive property
Replies: 3
Views: 32

Re: Extensive vs. intensive property

How relevant is this terminology for the exams in this class? What I mean is, will we have to specifically distinguish between what’s extensive or intensive, or is it just to conceptual understanding? It seems unlikely that an exam midterm would be about whether a property is extensive or intensive,...
by Diana A 2L
Sun Feb 02, 2020 11:48 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated system
Replies: 10
Views: 93

Re: Isolated system

In terms of work and heat equations for energy exchanges between systems and their surroundings, do the equations we went over in Wednesday’s lecture apply to isolated systems? Or do we just not consider energy exchanges for isolated systems at all? IN OTHER WORDS, will we have any isolated system q...
by Diana A 2L
Thu Jan 23, 2020 12:14 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Converting from Kp to Kc
Replies: 4
Views: 36

Converting from Kp to Kc

For the sake of this course, do we have to know the convention equation from Kp to Kc? And if we do, will it be on Test 1? And if it is, will the equation for it be on the equation sheet? Thank you.
by Diana A 2L
Thu Jan 23, 2020 12:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Test 1 Material
Replies: 3
Views: 31

Test 1 Material

In term of understanding the equilibrium constant K, do we have to know the thermodynamic interpretations of it? As in understanding how it relates to Gibbs Free Energy, considering we haven’t really covered Gibbs Free Energy yet.
by Diana A 2L
Mon Jan 20, 2020 12:02 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatliers Principle In relation to pressure
Replies: 6
Views: 46

Re: Le Chatliers Principle In relation to pressure

In lecture Professor Lavelle said that you can increase pressure by decreasing volume, but then he also said you can increase pressure in some other way. How else can you increase pressure in a system? Would increasing concentration achieve that based on the comments in this post. Thank you.
by Diana A 2L
Mon Jan 20, 2020 12:00 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Adding Inert Gas
Replies: 9
Views: 69

Re: Adding Inert Gas

What is considered an inert gas? Do we have to remember a list of them or is there a way to tell if a gas is inert?
by Diana A 2L
Sun Jan 19, 2020 11:56 pm
Forum: Ideal Gases
Topic: Ideal Gas meaning
Replies: 7
Views: 67

Re: Ideal Gas meaning

I have a question about the conditions required for an “ideal gas”. When something is at standard STATE conditions, which is considered 25 degrees Celsius and 1 atm, does the Ideal Gas Equation apply?
by Diana A 2L
Sun Jan 19, 2020 11:54 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Effect of Increasing Temperature on an Equilibrium System
Replies: 4
Views: 36

Effect of Increasing Temperature on an Equilibrium System

When you increase the temperature of an exothermic reaction, it is known to shift left. I understand this fact, but have trouble conceptualizing it and understanding precisely WHY. Why wouldn’t an exothermic reaction with added heat shift right since its inclined to release heat?
by Diana A 2L
Sun Jan 19, 2020 11:47 pm
Forum: Ideal Gases
Topic: When does the Ideal Gas Law Fail?
Replies: 7
Views: 54

Re: When does the Ideal Gas Law Fail?

Does the Ideal Gas Law only apply to scenarios in Standard Temperature and Pressure? (STP) Or can approximations still be made using the Ideal Gas Law Equation with other temperatures within a close range?
by Diana A 2L
Mon Dec 09, 2019 1:47 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: Hydrogen Bonding and Dipole-Dipole
Replies: 1
Views: 101

Hydrogen Bonding and Dipole-Dipole

Are hydrogen bonds a type of dipole-dipole interaction? Lets say for example you're asked to list the types of intermolecular forces a molecule exhibits. If you list hydrogen bonds as one, would you also list dipole-dipole interactions as another?
by Diana A 2L
Mon Dec 09, 2019 1:34 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: H bonding
Replies: 4
Views: 126

Re: H bonding

Why are hydrogen atoms bound to Carbon atoms not considered in determining hydrogen binding sites?
by Diana A 2L
Sat Dec 07, 2019 1:11 pm
Forum: Hybridization
Topic: Question 2F.3
Replies: 1
Views: 33

Question 2F.3

In this question, it asked to state how many Sigma and Pi bonds are in SO2. The best Lewis structure with the most balanced formal charges has 2 sigma and 2 pi bonds, but there is also a less dominant resonant structure that has 2 sigma and 1 pi bond. In this case, which would be the correct answer?...
by Diana A 2L
Mon Nov 25, 2019 12:00 am
Forum: Electronegativity
Topic: ionic character
Replies: 9
Views: 170

Re: ionic character

If a molecule has more ionic character, is it soluble in water? Even if its a covalent bond?
by Diana A 2L
Sun Nov 24, 2019 11:59 pm
Forum: Resonance Structures
Topic: Resonance
Replies: 5
Views: 158

Resonance

When writing a resonance structure, do we do the resonance of the Lewis structure with the best balance of formal charges, or are the structures with imbalanced formal charges that are still correct also count as resonance?
by Diana A 2L
Sun Nov 24, 2019 11:56 pm
Forum: Octet Exceptions
Topic: expanded octet
Replies: 7
Views: 185

Re: expanded octet

Why do P, S, and Cl have expanded octets if they don't have d-orbitals? It doesn't make much sense.
by Diana A 2L
Sun Nov 24, 2019 11:55 pm
Forum: Bond Lengths & Energies
Topic: Hydrogen Bonding and Dispersion
Replies: 5
Views: 142

Hydrogen Bonding and Dispersion

I'm a bit confused between the concepts of hydrogen bonding and dispersion. Can someone clarify the difference between the two?
by Diana A 2L
Sun Nov 24, 2019 11:50 pm
Forum: Sigma & Pi Bonds
Topic: Pi Bonding
Replies: 6
Views: 87

Pi Bonding

Do pi bonds also occur in higher level subshells like the f-subshell? Or is there a different type of bond beyond that?
by Diana A 2L
Wed Nov 20, 2019 10:29 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lewis Structures
Replies: 3
Views: 39

Re: Lewis Structures

Thank you!
by Diana A 2L
Sun Nov 17, 2019 11:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lewis Structures
Replies: 3
Views: 39

Lewis Structures

I have a question relating VSEPR models with Lewis structures. Knowing what we now know about bonding angles, do we draw Lewis structures also according to bond angles, or does it not matter?
by Diana A 2L
Sun Nov 17, 2019 11:56 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: bond order calculations
Replies: 4
Views: 61

Re: bond order calculations

Am I understanding this right: the bond order of a compound is the average of all the different bonds present between the individual atoms in the compound. For example, if there's a compound consisting of three atoms bonded by one single and one double bond, you'd take the average bond energy from c...
by Diana A 2L
Sun Nov 17, 2019 11:53 pm
Forum: Hybridization
Topic: Pi and Sigma Bonds
Replies: 17
Views: 407

Re: Pi and Sigma Bonds

Basically, pi and sigma bonds give you an idea of how electrons from different orbitals are shared within atoms in 3D space. That's really the only significance, and I believe that may be beyond the scope of this chemistry course.
by Diana A 2L
Sun Nov 17, 2019 11:52 pm
Forum: Hybridization
Topic: Pi and Sigma Bonds
Replies: 17
Views: 407

Re: Pi and Sigma Bonds

why do we need to give bonds a secondary name? what do the names mean? Yeah, why does it matter? It feels like they have no other significance other than giving bonds a new name. the significance of sigma and pi bonds are that they indicate the angles and axis upon which the covalent bonds between ...
by Diana A 2L
Sun Nov 17, 2019 11:46 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 9
Views: 77

Re: Bond Angles

So for the sake of the Test 2, will we be expected to list the bond angles if we're asked to identify a shape?
by Diana A 2L
Sun Nov 17, 2019 11:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Study Group
Replies: 2
Views: 52

Re: Study Group

Hey, I am down for a study group. If anyone wants to form one, email me at dmarut20@gmail.com
And then I'll give you my number:)
by Diana A 2L
Mon Nov 04, 2019 12:10 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Electron Configurations
Replies: 2
Views: 122

Electron Configurations

When we do electron configurations for elements, lets say we get an element like nitrogen with 3p^3 at the end. On the midterm, should we write it as 3p^3 or as px, py, pz?
by Diana A 2L
Sun Nov 03, 2019 11:58 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 9
Views: 176

Re: Atomic Radius

I still don't fully understand. If you're going horizontally across a row does atomic radius increase or decrease? And how about going down a column?
by Diana A 2L
Sun Nov 03, 2019 11:54 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Drawing Orbitals
Replies: 3
Views: 122

Drawing Orbitals

Will we be expected to know the shapes and models of orbitals for the midterm? Will a general understanding suffice? I still have trouble envisioning orbital structures in a 3D space just because I've never dealt with the Z-axis before.
by Diana A 2L
Sun Nov 03, 2019 11:52 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 9
Views: 176

Atomic Radius

I don't exactly understand an aspect of the atomic radius trend. Does the atomic radius increase across a row as you keep adding more electrons to the same shell? I know there would be more electron repulsion with lets say flourine rather than boron, so does that cause a radius increase?
by Diana A 2L
Sun Nov 03, 2019 11:49 pm
Forum: Trends in The Periodic Table
Topic: Electronegativity
Replies: 7
Views: 171

Electronegativity

Will we have to know general electronegativity trends for this upcoming midterm? I haven't fully solidified my concept of it yet and was wondering how much of it will be necessary for the midterm.
by Diana A 2L
Sun Nov 03, 2019 11:47 pm
Forum: *Shrodinger Equation
Topic: wavefunctions & orbitals relationship?
Replies: 5
Views: 171

Re: wavefunctions & orbitals relationship?

I like to think of it as the probability of a particles quantum state being dependent on the descriptions of each quantum number. A wavefunction is like the possible position, momentum, and spin of an electron combined. It basically defines an orbital of an electron.
by Diana A 2L
Sun Nov 03, 2019 11:37 pm
Forum: *Shrodinger Equation
Topic: Hamiltonian
Replies: 3
Views: 132

Re: Hamiltonian

In terms of the Hamiltonian in the context of the midterm, the variable itself is given on the formula sheet I believe, so for the purpose of the midterm, all you really have to know is the basic format of the Schroedinger equation: H(wavefunction)=E(wavefunction) and then just plug in the variable ...
by Diana A 2L
Sun Oct 27, 2019 11:57 pm
Forum: Ionic & Covalent Bonds
Topic: Polarity
Replies: 6
Views: 54

Polarity

Are covalent bonds polar or nonpolar? And is there a relation between electronegativity and polarity? I partially forgot my high school chemistry and don't exactly remember what electronegavity is a measure of.
by Diana A 2L
Sun Oct 27, 2019 11:53 pm
Forum: Dipole Moments
Topic: Atom Shapes
Replies: 2
Views: 31

Atom Shapes

Are we going to go over Vespr diagrams and have to learn the different atomic shapes and angles for this class and the final? I am asking because it seems like its going to go hand in had with the bonding properties and resonance stuff we are learning now.
by Diana A 2L
Sun Oct 27, 2019 11:50 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: S and D Oribitals
Replies: 1
Views: 47

S and D Oribitals

Why is it that with some atoms with electrons in the D-orbitals, the S-orbitals will have more energy than the D-orbitals. For example, why would a 4s1 electorn have more energy than a 3d5 electron?
by Diana A 2L
Sun Oct 27, 2019 11:46 pm
Forum: Trends in The Periodic Table
Topic: Shielding and Electron Replusion
Replies: 3
Views: 59

Shielding and Electron Replusion

Are the shielding effect and electron repulsion synonymous? Does electron repulsion occur as a result of shielding, or are they different concepts?
by Diana A 2L
Sun Oct 27, 2019 11:45 pm
Forum: Trends in The Periodic Table
Topic: Nuclear Charge
Replies: 2
Views: 35

Nuclear Charge

Is there a more significant decrease in nuclear charge as more electrons are being added to the same shell, or as there are more electrons but in energy levels that are further from the nucleus? Basically, I'm asking what the trends in the periodic table are for nuclear charge.
by Diana A 2L
Mon Oct 21, 2019 12:02 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Wave Function and Uncertainty
Replies: 3
Views: 53

Re: Wave Function and Uncertainty

Okay that makes sense. But what do you mean by location? Location in terms of which orbital?
by Diana A 2L
Sun Oct 20, 2019 11:58 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Orbitals and Energy Levels
Replies: 2
Views: 43

Orbitals and Energy Levels

Are orbitals different from energy levels? The relationship between the two is unclear to me. Are there orbitals within different energy levels? Is whether an electron is located in a certain energy level unrelated to what orbital it is in, or is there a connection between the two?
by Diana A 2L
Sun Oct 20, 2019 11:52 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Nodal Planes
Replies: 2
Views: 39

Nodal Planes

From my understanding, a nodal plane is an area where two or more lobes of a certain type of orbital meet? Is this a valid understanding of it, and also, what is the significance of nodal planes in quantum theory? Is it just to determine the structure of an atom's orbital?
by Diana A 2L
Sun Oct 20, 2019 11:45 pm
Forum: Quantum Numbers and The H-Atom
Topic: Quantum Numbers and Energy Levels
Replies: 2
Views: 54

Quantum Numbers and Energy Levels

Why do energy levels become closer together as the quantum number, n, increases? Why is there such a large gap between the first and second energy levels?
by Diana A 2L
Sun Oct 20, 2019 11:41 pm
Forum: Quantum Numbers and The H-Atom
Topic: Quantum Mechanics and Computers
Replies: 1
Views: 42

Quantum Mechanics and Computers

This question is quite off topic, but, I was curious, how are the concepts of quantum mechanics are applied to computers? Do the ideas behind quantum-computing originate from the fundamental concepts of the Quantum Theory in H-atoms? Does it go as far back to the basics as that?
by Diana A 2L
Sun Oct 20, 2019 11:35 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Wave Function and Uncertainty
Replies: 3
Views: 53

Wave Function and Uncertainty

This is more of a bigger question, conceptual question, but am I understanding this right? Basically, the uncertainty principle and the wave function are both different methods to finding out the locations of electrons in an atom and their distance from the nucleus (or which energy level they are lo...
by Diana A 2L
Mon Oct 14, 2019 12:06 am
Forum: Properties of Light
Topic: Combining Different Equations
Replies: 8
Views: 104

Re: Combining Different Equations

Also, when showing work, do we have to show the work with the overall equations combined, or can we show our work in more of a step by step process? Here's an example: Theres E=hv and C=(lambda)v Here, you can either plug in values individually to derive an answer, or you can combine the equations t...
by Diana A 2L
Sun Oct 13, 2019 11:58 pm
Forum: Properties of Light
Topic: What is Threshold Energy?
Replies: 9
Views: 92

Re: What is Threshold Energy?

Do ionization energy and threshold energy have the same numerical values? And what is the difference between the two?
by Diana A 2L
Sun Oct 13, 2019 11:57 pm
Forum: Properties of Light
Topic: Quantum Levels
Replies: 1
Views: 31

Quantum Levels

This is a conceptual question, but is it possible ever to have a frequency of electrons emitted that is different from the values defined by each energy level (n1, n2, etc.), and if it ism in what situation would that happen?
by Diana A 2L
Sun Oct 13, 2019 11:55 pm
Forum: Properties of Light
Topic: Homework
Replies: 11
Views: 83

Homework

For the five homework problems that are due each week for credit, will we receive full credit if we do the five problems all from the same section/topic?
by Diana A 2L
Sun Oct 13, 2019 11:51 pm
Forum: Properties of Light
Topic: MidTerms and Finals
Replies: 11
Views: 128

MidTerms and Finals

Will the midterms and final exams for this class be administered in the discussion period also?
by Diana A 2L
Sun Oct 13, 2019 11:47 pm
Forum: Properties of Light
Topic: Wave Frequency
Replies: 9
Views: 97

Wave Frequency

I have a conceptual question. For the frequency of a wave, is the frequency a total sum of all of the individual photons of that wave, or is the frequency the amount of energy present in each individual photon?

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