Search found 180 matches
- Sat Mar 14, 2020 10:27 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Elementary Steps
- Replies: 4
- Views: 377
Re: Elementary Steps
what even are elementary steps
- Sat Mar 14, 2020 10:27 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Activated Complex vs Transition State
- Replies: 5
- Views: 1143
Re: Activated Complex vs Transition State
805307623 wrote:Activated Complex- collection of intermediate molecules that are created as a chemical reaction progresses
Transition state- intermediate of a chemical reaction that makes up the highest potential energy
When do we use these concepts in the material that we have learned and will be tested on?
- Sat Mar 14, 2020 10:25 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalyst's effect on overall reaction
- Replies: 7
- Views: 486
Re: Catalyst's effect on overall reaction
jisulee1C wrote:since the slow step is the rate determining step, changing the activation energy of an already fast step will not change the rate because it is not changing the rate of the slow step
how do you determine the fast and slow step?
- Wed Mar 11, 2020 8:29 pm
- Forum: Administrative Questions and Class Announcements
- Topic: final
- Replies: 14
- Views: 979
Re: final
we're all on standby until he updates us
- Mon Mar 09, 2020 6:07 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts
- Replies: 28
- Views: 1807
Re: Catalysts
AnnaYan_1l wrote:Catalysts reduce the activation energy between reactants to products, meaning it takes less energy to make the forward reaction occur
does this affect the reverse reaction too?
- Mon Mar 09, 2020 6:03 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalyst vs Intermediate
- Replies: 6
- Views: 108967
Re: Catalyst vs Intermediate
Kayla Denton 1A wrote:Catalysts are present as reactants in the very beginning and products at the end. Intermediates, on the other hand, are not present in the initial reaction but are produced within one of the steps and then consumed within another step.
a catalyst is one of the reactants?
- Mon Mar 09, 2020 5:55 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: steady state v preeq
- Replies: 4
- Views: 385
Re: steady state v preeq
Jiyoon_Hwang_2I wrote:For steady state, the first step of the reaction must be slower than the second step. On the other hand, for pre-equilibrium, the first step must be faster than the second step.
how do you know which step is the fast step and which is the slow step
- Mon Mar 09, 2020 5:52 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: k'
- Replies: 6
- Views: 439
Re: k'
Alexis Webb 2B wrote:k' is the rate constant for the reverse reaction.
is this just the reciprocal of the forward reaction?
- Mon Mar 09, 2020 5:51 pm
- Forum: General Rate Laws
- Topic: First vs Second vs Zero Order
- Replies: 7
- Views: 605
Re: First vs Second vs Zero Order
they all have different relationships with time and therefore produce different graphs.
- Mon Mar 09, 2020 5:48 pm
- Forum: General Rate Laws
- Topic: overall order
- Replies: 5
- Views: 462
Re: overall order
the overall order is equal to the sum of all the orders of the reactants. The order of each reactant is the exponential value of the reactant
- Sun Mar 08, 2020 1:12 pm
- Forum: Zero Order Reactions
- Topic: third order
- Replies: 11
- Views: 1226
Re: third order
Gillian Ward 1F wrote:Possibly, it is in the curriculum.
what is the third order?
- Sun Mar 08, 2020 1:10 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Study Advice
- Replies: 73
- Views: 7202
Re: Study Advice
I personally recommend the online sapling learning problems. The review sessions are great but I've noticed the sapling learning problems are more in line with the test material and you can work at your own pace. Also the site provides very in depth explanations about each problem which I find very ...
- Thu Mar 05, 2020 8:58 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: lnQ vs logQ
- Replies: 5
- Views: 395
Re: lnQ vs logQ
When would you use E=E°-(RT/nF)lnQ vs E=E°-(0.05916V/n)logQ ? Also, I understand that you can substitute RT/F for 0.025963 for the ln equation when its under standard condition - 25 degree celsius. Is this correct? Yes, also I use the log one when dealing with H+ or OH- concentration; however, both...
- Mon Mar 02, 2020 10:09 pm
- Forum: Balancing Redox Reactions
- Topic: Acidic vs. Basic Solutions
- Replies: 8
- Views: 671
Re: Acidic vs. Basic Solutions
if it is in acidic solution you use H+ to balance out the equation and if it is in basic solution you use OH-
- Mon Mar 02, 2020 4:47 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: determine n
- Replies: 16
- Views: 1439
Re: determine n
Alison Trinh 1E wrote:n represents the order of the reactant, which in turn gives insight into the mechanism of the reaction.
how do you know what the order is
- Mon Mar 02, 2020 4:47 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: determine n
- Replies: 16
- Views: 1439
Re: determine n
Samantha Silva 1F wrote:The number of moles.
moles of what?
- Mon Mar 02, 2020 4:46 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Order
- Replies: 5
- Views: 489
Re: Order
Vicki Liu 2L wrote:Reaction order is essentially the power to which a reactant concentration is raised in order to give an accurate relationship between it and the rate of the overall reaction.
how do you find this number
- Mon Mar 02, 2020 4:45 pm
- Forum: General Rate Laws
- Topic: Order
- Replies: 5
- Views: 533
Re: Order
You can look at the reactions graph. Which ever graph produces a straight line will give you the reaction order. For zero order the graph would be (A) v time and would give a straight line with a -slope. First order reaction would be ln(A) v time and would give a straight line with a -slope. Second...
- Mon Mar 02, 2020 4:43 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: instantaneous rate
- Replies: 16
- Views: 975
Re: instantaneous rate
Because it gives the exact slope at a specific time rather than an average of slopes over a range of t values
- Sat Feb 29, 2020 12:00 pm
- Forum: Van't Hoff Equation
- Topic: HW 11.83
- Replies: 4
- Views: 1083
Re: HW 11.83
Eesha Chattopadhyay 2K wrote:Can we also use the ln(k2/k1)=-delta H standard/R[1/t1 -1/t2] to solve this problem or do we have to find the separate standard G to find the values of K?
the question says to use data in the appendix so I'd find the standard G to find K values
- Sat Feb 29, 2020 11:57 am
- Forum: Van't Hoff Equation
- Topic: Derive [ENDORSED]
- Replies: 4
- Views: 584
Re: Derive [ENDORSED]
WYacob_2C wrote:How can you derive ln(K1/K2)= -delta H/R (1/T1 - 1/T2) from the Van't Hoff equation given on the formula sheet: lnK=-delta H/RT + delta S/R ? Thank you in advance.
it honestly would probably be easier to just memorize it than try deriving it during the test
- Tue Feb 25, 2020 5:40 pm
- Forum: Van't Hoff Equation
- Topic: Van’t Hoff Equation
- Replies: 11
- Views: 947
Re: Van’t Hoff Equation
kristi le 2F wrote:The vant hoff equation can be used to calculate K at different temperatures if stand enthalpy of real lion is known.
what is real lion
- Tue Feb 25, 2020 5:38 pm
- Forum: Van't Hoff Equation
- Topic: Converting K back to Kc
- Replies: 5
- Views: 504
Re: Converting K back to Kc
kennedyp wrote:What's the equation needed to convert K back to Kc? I assumed you would just rearrange the Kc to K equation, but I wanted to ask just to be sure.
aren't those the same
- Mon Feb 24, 2020 4:19 pm
- Forum: Van't Hoff Equation
- Topic: Van't Hoff Equation
- Replies: 7
- Views: 550
Re: Van't Hoff Equation
TarynD_1I wrote:I think we use Van't Hoff when trying to calculate how K is affected by a change in temperature
yes this is correct as we have a K1 and K2 and a T1 and T2
- Mon Feb 24, 2020 4:18 pm
- Forum: Van't Hoff Equation
- Topic: deltaS/R
- Replies: 7
- Views: 496
Re: deltaS/R
they aren't ignored, the just get cancelled out when deriving the new equation
- Mon Feb 24, 2020 4:10 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Positive and negative standard potential
- Replies: 3
- Views: 184
Re: Positive and negative standard potential
Brian_Ho_2B wrote:Substances with a higher, positive standard reduction potentials are not able to reduce H+ to H2, while substances with lower, negative reduction potentials can reduce H+ to H2.
why would the substance with a higher reduction potential has less potential to reduce H+? Sounds counter intuitive
- Mon Feb 24, 2020 4:07 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst
- Replies: 7
- Views: 551
Re: Nernst
DesireBrown1J wrote:Why is n moles of electrons transferred instead of the number of electrons transferred? How do we convert it into moles if they are electrons?
They are the same. The number of electrons is the moles of electrons.
- Mon Feb 24, 2020 2:37 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Usage for Nernst equation
- Replies: 7
- Views: 659
Re: Usage for Nernst equation
Kate Osborne 1H wrote:standard conditions are a specific ratio of products to reactants and if the ratio is not that then you have to use the nernst equation
are you referring to K? what else would a specific ratio be
- Mon Feb 24, 2020 2:35 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Electrode Potential
- Replies: 4
- Views: 347
Re: Electrode Potential
the reduction potential. Once you determine which half reaction is oxidized, you change the sign of this potential.
- Mon Feb 24, 2020 2:32 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Electromotive Force
- Replies: 3
- Views: 347
Re: Electromotive Force
the electromotive force is Ecell, the max potential when very little current is flowing. When there is no current flowing, that is when the difference is at its maximum. I thought electromotive force was the max potential of the cell before any current flow? How do you determine "little curren...
- Mon Feb 24, 2020 2:27 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt bridge
- Replies: 6
- Views: 449
Re: Salt bridge
charleejohnson1L wrote:The salt bridge keeps the two solutions neutral so the systems can exchange electrons. I hope this helps :)
it allows for the flow of ions as well
- Sun Feb 23, 2020 4:26 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: 6N.3
- Replies: 6
- Views: 499
Re: 6N.3
805291863 wrote:Also, how is the n value determined here?
n value is determined by the moles of electrons in each of the balanced half rxn equations
- Thu Feb 20, 2020 12:53 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Answer is different for 5G.15
- Replies: 5
- Views: 360
Re: Answer is different for 5G.15
KeyaV1C wrote:I got -27 kJ/mol as my answer.
how did you get this??
- Wed Feb 19, 2020 7:42 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Answer is different for 5G.15
- Replies: 5
- Views: 360
Re: Answer is different for 5G.15
I keep getting -2.7 kJ as well. Can someone explain what we are doing wrong?
- Wed Feb 19, 2020 7:12 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: 6N1 part b
- Replies: 1
- Views: 135
6N1 part b
if the reduction half of the rxn goes from In3+ to In2+, why does the answer key say that 2 electrons are added to In3+ to get to In2+. Why is it not 1 electron???
- Tue Feb 18, 2020 6:40 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nerst Equation
- Replies: 10
- Views: 1060
Re: Nerst Equation
What is the nerst equation?
- Tue Feb 18, 2020 6:38 pm
- Forum: Balancing Redox Reactions
- Topic: Understanding Half-Reactions
- Replies: 11
- Views: 723
Re: Understanding Half-Reactions
half reactions let us understand what is happening exactly to the molecule being reduced and same for the molecule being oxidized. Each reaction on their own has cell potential measured in volts; so, by looking at both measures, we can add them together to get the cell potential as a whole. But ove...
- Tue Feb 18, 2020 6:38 pm
- Forum: Balancing Redox Reactions
- Topic: Understanding Half-Reactions
- Replies: 11
- Views: 723
Re: Understanding Half-Reactions
half reactions let us understand what is happening exactly to the molecule being reduced and same for the molecule being oxidized. Each reaction on their own has energy potential measured in volts; so, by looking at both measures, we can add them together to get the energy potential as a whole. But ...
- Tue Feb 18, 2020 6:34 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Electrochemical cell
- Replies: 4
- Views: 307
Re: Electrochemical cell
So this redox reaction occurs within a single cell?
- Tue Feb 18, 2020 6:32 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Ecell
- Replies: 5
- Views: 693
Re: Ecell
what is the difference between Ecell and Eocell?
- Tue Feb 18, 2020 6:30 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n in -nFE
- Replies: 14
- Views: 893
Re: n in -nFE
n represents the number of electrons transferred in this equation!
- Sun Feb 16, 2020 8:24 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation Number
- Replies: 2
- Views: 215
Oxidation Number
How are we supposed to know the oxidation number for each element in a compound?
- Sun Feb 16, 2020 4:45 pm
- Forum: Balancing Redox Reactions
- Topic: oxidation vs reduction
- Replies: 19
- Views: 1028
Re: oxidation vs reduction
if the compound is oxidized, it will lose electrons. And if it is reduced, it will gain electrons. You can determine which process the compound undergoes by looking at its change in charge.
- Sun Feb 16, 2020 4:43 pm
- Forum: Balancing Redox Reactions
- Topic: Electrochemisty
- Replies: 10
- Views: 669
Re: Electrochemisty
it is the study of chemical processes that cause electrons to move, resulting in electricity that is generated by the movements of electrons from one element to another. This reaction is known as a redox reaction and is important because we will be doing many redox reaction problems in electrochemis...
- Tue Feb 11, 2020 9:53 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: degeneracy W
- Replies: 7
- Views: 579
Re: degeneracy W
Ryan Lee 1E wrote:Na is going to be Avogadro's number whereas lowercase n is going to be the number of moles.
When do we use Avogadro's number instead of moles?
- Tue Feb 11, 2020 9:52 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: Residual Entropy
- Replies: 7
- Views: 581
Re: Residual Entropy
DarrenKim_3G wrote:residual entropy is the remaining entropy left in molecules at 0 K
what does that mean? and when will we use this?
- Tue Feb 11, 2020 9:51 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Cv vs. Cp?
- Replies: 3
- Views: 286
Re: Cv vs. Cp?
if there is both a change in volume and temperature you do two separate calculations for each using the proper C respectively and then add the two together
- Tue Feb 11, 2020 9:49 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Delta U
- Replies: 8
- Views: 590
Re: Delta U
this is the internal energy of the system. so w would be the work either done by or on the system and q would be the heat either absorbed or given off by the system. the changes are looked at in the perspective of the system
- Tue Feb 11, 2020 9:47 pm
- Forum: Calculating Work of Expansion
- Topic: Midterm equation sheet
- Replies: 16
- Views: 732
Re: Midterm equation sheet
yes, it is the same one
- Sat Feb 08, 2020 3:40 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Units for heat of reaction
- Replies: 9
- Views: 297
Re: Units for heat of reaction
do you have to explicitly state per mole or is that implied already
- Thu Feb 06, 2020 12:31 pm
- Forum: Phase Changes & Related Calculations
- Topic: about system and surroundings
- Replies: 8
- Views: 379
Re: about system and surroundings
so the surrounding is the universe?
- Tue Feb 04, 2020 1:03 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: negative entropy
- Replies: 4
- Views: 178
Re: negative entropy
Lauren Tanaka 1A wrote:Negative entropy is possible and just means that there is an overall decrease in entropy for the given system.
what does decrease in entropy mean for the system though
- Tue Feb 04, 2020 1:03 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: negative entropy
- Replies: 4
- Views: 178
Re: negative entropy
eduardomorales5 wrote:Negative entropy means there is a decrease in the disorder of the system or increase in the order of the system.
how is it both?
- Tue Feb 04, 2020 1:02 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated systems
- Replies: 4
- Views: 371
Re: Isolated systems
Mitchell Koss 4G wrote:Closed is like a test tube with a cap on it, so solution can be heated or lose heat.
Isolated is behind thick walls like a bomb calorimeter or thermos so no outside interaction can occur.
how do we determine which one it is, or will it be stated?
- Tue Feb 04, 2020 1:01 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: q and w
- Replies: 10
- Views: 583
Re: q and w
Nawal Dandachi 1G wrote:q would be positive if heat is being added to the system and negative if heat is being removed. w would be positive if work is done by the system and negative if work is done on the system.
what is an example of work being done on or to the system?
- Tue Feb 04, 2020 12:59 pm
- Forum: Calculating Work of Expansion
- Topic: when to use...?
- Replies: 4
- Views: 192
Re: when to use...?
ALegala_2I wrote:You use w=-PV when there is an expansion occurring at a constant external pressure. You use the other equation when there is a change in internal and external pressure for expansion work.
what is the other equation?
- Mon Feb 03, 2020 3:37 pm
- Forum: Phase Changes & Related Calculations
- Topic: Calorimeters
- Replies: 8
- Views: 467
Re: Calorimeters
how many types are there?
- Wed Jan 29, 2020 1:02 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: System vs Surroundings
- Replies: 14
- Views: 2138
Re: System vs Surroundings
Yes, the system vs. surrounding should not be something you have to memorize. As mentioned before, the system is simply the situation in question, such as a piston. Since the first law of thermodynamics states the conservation of energy, a change in energy of the system means a resultant change in ...
- Wed Jan 29, 2020 12:56 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Systems at equilibrium
- Replies: 3
- Views: 195
Re: Systems at equilibrium
We will discuss it more when we start talking about thermodynamics. For now, all we need to know is that there is a difference in the amount of work done depending on whether the gaseous system is under pressure or not. what is this difference? Is this just a concept we have to know or are their fo...
- Mon Jan 27, 2020 12:57 pm
- Forum: Phase Changes & Related Calculations
- Topic: ∆H
- Replies: 17
- Views: 681
Re: ∆H
MingdaH 3B wrote:No, you can touch it.
wait what this a serious response lol
- Mon Jan 27, 2020 12:42 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Week 4 Homework
- Replies: 11
- Views: 359
Re: Week 4 Homework
Outline 3 (Thermochemistry)
- Mon Jan 27, 2020 12:41 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Methods to Calculate Enthalpies
- Replies: 6
- Views: 408
Re: Methods to Calculate Enthalpies
Brian J Cheng 1I wrote:Depends on the information given and the setup of the question. For example: if multiple rxn equations are given with their respective enthalpy changes, then you might suspect Hess's Law. If bond energies are given, then you might use bond energies.
what exactly are bond energies?
- Mon Jan 27, 2020 12:39 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: pressure and enthalpy
- Replies: 5
- Views: 257
Re: pressure and enthalpy
Why does enthalpy increase as temperature increases?
- Mon Jan 27, 2020 12:38 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: q=mCdeltaT
- Replies: 15
- Views: 8196
Re: q=mCdeltaT
if the equation uses the g variable then use grams. If it uses the m variable which is usually represented by n, use number of moles.
- Mon Jan 27, 2020 12:33 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: bomb calorimeter
- Replies: 5
- Views: 322
Re: bomb calorimeter
it measures heat of a system with CV (the volume is fixed so pressure is not constant)
- Mon Jan 27, 2020 12:30 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Extensive vs intensive propeties
- Replies: 5
- Views: 375
Re: Extensive vs intensive propeties
well,heat capacity is an extensive property because it depends on the amount of substance. If we divide the heat capacity by the amount of substance, it becomes an intensive property.
- Mon Jan 27, 2020 12:27 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Signs for enthalpy
- Replies: 8
- Views: 518
Re: Signs for enthalpy
the sign of enthalpy indicates if the reaction is endothermic (positive) or exothermic (negative)
- Sun Jan 26, 2020 2:03 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Exothermic reaction
- Replies: 18
- Views: 737
Re: Exothermic reaction
in an exothermic reaction if temp is decreased the rxn will move forward as it is a "product" (is released)
- Thu Jan 23, 2020 12:54 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: H20 in the ICE table
- Replies: 26
- Views: 1516
Re: H20 in the ICE table
you leave out any molecule that is a pure liquid or solid. If H20 is in a gas phase, then it is included
- Wed Jan 22, 2020 12:28 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: pKa and pKb
- Replies: 17
- Views: 931
Re: pKa and pKb
pka and pkb are added together to get 14; so, if you know one, you can subtract it from 14 to get the other
- Wed Jan 22, 2020 12:26 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pressure and volume
- Replies: 3
- Views: 153
Re: pressure and volume
volume and pressure are inversely related. it's easy to answer those questions if you memorize that
- Tue Jan 21, 2020 12:55 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: expanding the volume
- Replies: 3
- Views: 136
Re: expanding the volume
because the pressure is decreased and in order to minimize this change, the reaction reaction move towards the side with more moles so there is more pressure
- Mon Jan 20, 2020 12:30 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pH sig figs
- Replies: 5
- Views: 188
Re: pH sig figs
One of the UAs said that the amount of sig figs in the problem is the amount of sig figs you place after the decimal for pH
- Sun Jan 19, 2020 12:21 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q < K
- Replies: 16
- Views: 850
Re: Q < K
correct that is what that means. forward rxn favors the product
- Sun Jan 19, 2020 12:20 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Test 1
- Replies: 6
- Views: 346
Re: Test 1
just the material from weeks one and two!
- Sun Jan 19, 2020 12:18 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: 5% rule
- Replies: 10
- Views: 500
Re: 5% rule
because the change in x is so small, the original molarity of the molecule being changed by x is a suffice approximation.
- Sun Jan 19, 2020 12:17 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Pressure
- Replies: 5
- Views: 242
Re: Pressure
it goes to the side with less moles.
- Sun Jan 19, 2020 12:16 pm
- Forum: Ideal Gases
- Topic: R Constant
- Replies: 7
- Views: 282
Re: R Constant
Kimberly Koo 2I wrote:R is the universal gas constant, which is 0.082 L.atm/mol.K
there are different R constants for different units though
- Sun Jan 19, 2020 12:14 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE Box
- Replies: 4
- Views: 157
Re: ICE Box
pure liquids and solids are not involved in the ice box so H20 wouldn't be involved in liquid form. However, it is when it is in gas form like the examples in class.
- Sun Jan 19, 2020 12:10 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Different Values for K and Kc?
- Replies: 3
- Views: 302
Re: Different Values for K and Kc?
that is strange. I thought that K and Kc were the same. The only thing I can think of is if K were calculated in Pressure and than converted to Kc but I didn't do the math to test that. I also don't know why it would be calculated differently.
- Thu Jan 16, 2020 1:00 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Autoprolysis
- Replies: 9
- Views: 686
Re: Autoprolysis
Wendy Perez 1E wrote:Adding to this conversation, what does amphiprotic mean again?
can accept or donate a proton
- Thu Jan 16, 2020 12:58 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: How to make ICE box
- Replies: 17
- Views: 1272
Re: How to make ICE box
the moles represent the amount of X that will change. If the molecules go into the eq the change is -, and if the molecules come out of the eq the change is +
- Mon Jan 13, 2020 12:51 pm
- Forum: Ideal Gases
- Topic: Topics for Test 1
- Replies: 17
- Views: 707
Re: Topics for Test 1
The UA's said the material would cover up to this friday's class material so I would focus of the first two weeks of information. The lecture videos that Lavelle posted cover a lot of the information and have great practice problems!
- Mon Jan 13, 2020 12:46 pm
- Forum: Ideal Gases
- Topic: ICE Table
- Replies: 9
- Views: 521
Re: ICE Table
You should calculate Q so you know which direction the reaction is moving and then you can identify if the products or reactants are favored to determine if x is positive or negative for each molecule
- Mon Jan 13, 2020 12:43 pm
- Forum: Ideal Gases
- Topic: R constant
- Replies: 6
- Views: 282
R constant
When do we know when to use which R constant?
What are the two R constants and when are they used?
Is the unit for gas measured in atm pressure or bars?
What are the two R constants and when are they used?
Is the unit for gas measured in atm pressure or bars?
- Mon Jan 13, 2020 12:37 pm
- Forum: Ideal Gases
- Topic: Understanding Q
- Replies: 19
- Views: 756
Re: Understanding Q
To solve for Q we have to be given the values of each product and reactant, correct?
- Mon Jan 13, 2020 12:34 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: What is this?
- Replies: 23
- Views: 1490
Re: What is this?
This principle tries to minimize the effect of change by shifting the direction of the reaction in order to maintain equilibrium
- Mon Jan 13, 2020 12:28 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Reaction shifts right or left?
- Replies: 14
- Views: 1599
Re: Reaction shifts right or left?
Yes, if the reaction is shifted to the left that means that the are more moles on the left side of the reaction which are the reactants. While if the reaction is shifted to the right that means there are more moles on the right side of the reaction which are the products. if there are more moles on...
- Mon Jan 13, 2020 12:24 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q=K
- Replies: 14
- Views: 672
Re: Q=K
Q doesn't have to be strictly not at equilibrium. It can be at any point in the reaction including equilibrium, K.
- Mon Jan 13, 2020 12:21 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: PV=nRT
- Replies: 9
- Views: 414
Re: PV=nRT
have we gone over this in class in an example equation?
- Thu Jan 09, 2020 7:06 pm
- Forum: Ideal Gases
- Topic: Understanding Q
- Replies: 19
- Views: 756
Re: Understanding Q
do you omit pure solids and liquids while solving for K too?
- Thu Jan 09, 2020 6:55 pm
- Forum: Ideal Gases
- Topic: converting Kc to Kp
- Replies: 13
- Views: 464
Re: converting Kc to Kp
the volume is already included in the concentration as it is moles over volume
- Wed Jan 08, 2020 8:17 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Sapling Learning
- Replies: 9
- Views: 535
Sapling Learning
Are the assignments on sapling learning mandatory? And if so, when are they due?
- Wed Jan 08, 2020 7:42 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: HW 5I.5
- Replies: 3
- Views: 175
Re: HW 5I.5
correct it is just a unit
- Wed Jan 08, 2020 1:24 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Effects of Concentration on Equilibrium
- Replies: 6
- Views: 277
Re: Effects of Concentration on Equilibrium
yes it will be temporarily shifted
- Wed Jan 08, 2020 1:19 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K vs Kp vs Kc
- Replies: 9
- Views: 388
Re: K vs Kp vs Kc
K is the general term for equilibrium constant. Kp is for reaction involving gases and Kc is for reactions involving aqueous.
- Tue Jan 07, 2020 6:24 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Expression for K
- Replies: 4
- Views: 189
Expression for K
Why d we have to put P in front of the molecules? for example= (P O2) + (P H4)
- Mon Jan 06, 2020 7:24 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5G.3
- Replies: 8
- Views: 552
Re: 5G.3
partial pressure is used because the reaction only involves gases
- Fri Dec 06, 2019 9:43 pm
- Forum: Identifying Acidic & Basic Salts
- Topic: deciding whether the solution of a salt is basic, acidic, or neutral
- Replies: 5
- Views: 661
Re: deciding whether the solution of a salt is basic, acidic, or neutral
If, in the presence of water, a salt gains an H+ (becoming an acid) and produces OH- ions, the solution will be basic. If, in the presence of water, a salt loses an H+ (becoming a base) and produces H+ ions, the solution will be basic. <- you mean acidic??** ex: C2H3O2 (-) (aq) + H2O (l) ---> HC2H3...
- Fri Dec 06, 2019 9:39 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Weak vs Strong acids and bases
- Replies: 6
- Views: 486
Re: Weak vs Strong acids and bases
a weak base will have a lower pH than a strong base