Search found 127 matches

by Malia Shitabata 1F
Fri Mar 13, 2020 11:40 am
Forum: General Rate Laws
Topic: Average rate vs unique rate
Replies: 4
Views: 33

Average rate vs unique rate

How do you know when to use the average rate vs the unique rate?
by Malia Shitabata 1F
Thu Mar 12, 2020 8:07 pm
Forum: General Rate Laws
Topic: Instantaneous and Average Rate
Replies: 3
Views: 22

Instantaneous and Average Rate

At equilibrium, the instantaneous rate is 0. Does this mean the average rate is also 0 too? Because I know they can be different for [R] and [P].
by Malia Shitabata 1F
Wed Mar 11, 2020 12:59 am
Forum: General Rate Laws
Topic: 7A.3
Replies: 5
Views: 46

7A.3

Ethene is a component of natural gas, and its combustion has been thoroughly studied. At a certain temperature and pressure, the unique rate of the combustion reaction C2H4(g)+3O2(g)->2CO2(g)+2H2O(g) is 0.44 mol/Ls. What is the rate at which oxygen reacts. Why do you multiply 0.44 by 3 instead of le...
by Malia Shitabata 1F
Tue Mar 10, 2020 7:47 pm
Forum: Administrative Questions and Class Announcements
Topic: Class Cancellation
Replies: 3
Views: 102

Class Cancellation

Since classes were canceled, do we still have homework due in discussion? Is homework canceled since we can't go to discussion?
by Malia Shitabata 1F
Tue Mar 10, 2020 5:20 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Angular dependence
Replies: 2
Views: 17

Angular dependence

I wrote in my notes from the temperature and reaction rate section that the stricter the angular dependence, the bigger k is and if angular dependence is lower, A is lower. I'm not sure I wrote that down right. Can someone confirm?
by Malia Shitabata 1F
Tue Mar 10, 2020 5:18 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Pre activation factor
Replies: 1
Views: 12

Pre activation factor

What is the pre activation factor and which equation is it used in?
by Malia Shitabata 1F
Tue Mar 10, 2020 5:15 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Dimer
Replies: 1
Views: 13

Dimer

When we were discussing pre-equilibrium approach in class, the first step was a fast bimolecular dimerization. What is a dimer?
by Malia Shitabata 1F
Fri Mar 06, 2020 2:39 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Forward and reverse reaction rates
Replies: 4
Views: 32

Forward and reverse reaction rates

For A+B->C+D, the forward rate is k[A][B] and for the reverse reaction C+D->A+B, the rate is k'[C][D]. Why is it k' as opposed to just k?
by Malia Shitabata 1F
Fri Mar 06, 2020 2:27 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Molecularity
Replies: 4
Views: 53

Molecularity

If there's just one reactant going to product A->P, it's unimolecular and two reactants is bimolecular. If there are three reactants, it's termolecular so is four reactants tetramolecular or is it just considered termolecular or something completely different altogether like polymolecular?
by Malia Shitabata 1F
Tue Mar 03, 2020 7:51 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: E and Eº
Replies: 1
Views: 26

E and Eº

How are Ecell and Eºcell temperature dependent? Can someone explain this conceptually?
by Malia Shitabata 1F
Tue Mar 03, 2020 6:27 pm
Forum: Balancing Redox Reactions
Topic: 6L.9 part a
Replies: 2
Views: 31

6L.9 part a

Write balanced half reactions for the redox reaction of an acidified solution of potassium permanganate and iron (II) chloride

How do you know which element is going to be in the anode vs cathode?
by Malia Shitabata 1F
Tue Mar 03, 2020 12:09 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6.53
Replies: 2
Views: 37

6.53

If you were to construct a concentration cell in which one half-cell contains 1.0 M CrCl3 (aq) and the other half-cell contains 0.0010 M CrCl3 (aq), and both electrodes were chromium, at which electrode would reduction be spontaneous? Why does the half-cell with the greater concentration get reduced...
by Malia Shitabata 1F
Mon Mar 02, 2020 11:50 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N.13 part a
Replies: 3
Views: 38

6N.13 part a

Calculate the reaction quotient, Q, for the following cell reactions, given the measured values of the cell potential. balance the chemical equations by using the smallest whole number coefficients: Pt(s)|Sn4+(aq), Sn2+(aq)||Pb4+(aq), Pb2+(aq)|C(gr), Ecell=+1.33 Is there a typo in the answer because...
by Malia Shitabata 1F
Sat Feb 29, 2020 10:13 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Phases in cell diagrams
Replies: 1
Views: 12

Phases in cell diagrams

When writing cell diagrams, does it matter the order of two molecules of the same phase? For example does it matter if it's Pt(s)|H2(g)|H+(aq)||Fe3+(aq), Fe2+(aq)|Pt(s) or Pt(s)|H2(g)|H+(aq)||Fe2+(aq), Fe3+(aq)|Pt(s) and I switch the iron ions around?
by Malia Shitabata 1F
Thu Feb 27, 2020 2:30 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.5 part b
Replies: 2
Views: 23

6L.5 part b

Write the half--reactions, the balanced equation for the cell reaction, and the cell diagram fo reach of the following skeletal equations: Ce4+(aq)+I-(aq)->I2(s)+Ce3+(aq) When writing the cell diagram, how do you know when to add Pt because it's not part of the initial equation, but other equations ...
by Malia Shitabata 1F
Thu Feb 27, 2020 2:23 pm
Forum: Balancing Redox Reactions
Topic: 6K.3 part d
Replies: 1
Views: 24

6K.3 part d

Balance each of the following skeletal equations by using oxidation and reduction half-reactions. All the reactions take place in acidic solution. Identify the oxidizing agent and reducing agent in each reaction: Reaction of chlorine in water Cl2(g)->HClO(aq)+Cl2(g) I thought the two reactions (unba...
by Malia Shitabata 1F
Wed Feb 26, 2020 12:15 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.1
Replies: 2
Views: 29

6L.1

Calculate the standard reaction Gibbs free energy for the following cell reaction 2Ce^4+ (aq)+3I-(aq)-->2Ce^3+(aq)+I3-(aq), Ecellº=+1.08 V. I understand you're supposed to use ∆G=-nFE, but how do you know which moles to use? How do you know they come from Ce and not I?
by Malia Shitabata 1F
Tue Feb 25, 2020 11:58 pm
Forum: Balancing Redox Reactions
Topic: Acidic vs basic solution
Replies: 2
Views: 30

Acidic vs basic solution

How can you tell if a reaction is taking place in a basic or acidic solution if the question doesn't tell you?
by Malia Shitabata 1F
Sun Feb 23, 2020 1:02 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: ∆G=-nFE
Replies: 3
Views: 39

∆G=-nFE

Is ∆G=-nFE used when the battery is at equilibrium? I thought Lavelle said something along those lines, but I think I may have misheard.
by Malia Shitabata 1F
Thu Feb 20, 2020 9:06 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Half cells
Replies: 2
Views: 14

Half cells

Do half cells only refer to standard hydrogen electrodes or can they be any electrochemical cell?
by Malia Shitabata 1F
Thu Feb 20, 2020 8:29 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: E cell values
Replies: 3
Views: 22

E cell values

If the E cell value is negative, this means reduction isn't spontaneous. Does this mean that oxidation is spontaneous for a negative value and vice versa for a positive value or does it not work that way?
by Malia Shitabata 1F
Thu Feb 20, 2020 12:19 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Standard hydrogen electrode [ENDORSED]
Replies: 3
Views: 100

Standard hydrogen electrode [ENDORSED]

Why do we compare the electron transfer of all cells to a standard hydrogen electrode as opposed to another element electrode?
by Malia Shitabata 1F
Wed Feb 19, 2020 4:43 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: i
Replies: 1
Views: 26

i

As the limit of i --> 0, the max potential is reached but what does i represent?
by Malia Shitabata 1F
Tue Feb 11, 2020 7:48 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 4.19
Replies: 1
Views: 27

4.19

Calculate the molar kinetic energy (in joules per mole) of Kr(g) at (a) 55.85ºC and (b) 54.85ºC. When using 3/2RT, I used the gas constant 8.314 J/Kmol and T in Kelvin so 333.85 K and 332.85 K respectively for a and b. I didn't get the right J/mol so I'm not sure what I did wrong? For part a, I got ...
by Malia Shitabata 1F
Tue Feb 11, 2020 7:45 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Units for Heat Capacity & Specific Heat Capacity
Replies: 2
Views: 46

Re: Units for Heat Capacity & Specific Heat Capacity

I feel like it's probably just best to leave it in J/ºC especially since the constants we get are usually in that form unless they explicitly ask for another form.
by Malia Shitabata 1F
Tue Feb 11, 2020 6:42 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 4.15
Replies: 1
Views: 50

4.15

Hydrochloric acid oxidizes zinc metal in a reaction that produces hydrogen gas and chloride ions. A piece of zinc metal of mass 8.5 g is dropped into an apparatus containing 800.0 mL of 0.500 M HCl (aq). If the initial temperature of the hydrochloric acid solution is 25ºC, what is the final temperat...
by Malia Shitabata 1F
Mon Feb 10, 2020 10:00 pm
Forum: Calculating Work of Expansion
Topic: 4.7A
Replies: 1
Views: 51

4.7A

Calculate the work that must be done against the atmosphere for the expansion of the gaseous products in the combustion of 1.00 mol C6H6(l) at 25ºC and 1.00 bar. I balanced the equation for 2 moles of C6H6 instead of 1 mole like the solution manual did since the moles of oxygen would be a fraction. ...
by Malia Shitabata 1F
Mon Feb 10, 2020 7:38 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 4D.7
Replies: 1
Views: 18

4D.7

Oxygen difluoride is a colorless, very poisonous gas that reacts rapidly and exothermically with water vapor to produce O2 and HF: OF2(g) + H2O(g) --> O2(g) + 2HF(g) ∆H=-318 kJ What is the change in internal energy for the reaction of 1.00 mol OF2? I understand that for this problem you're supposed ...
by Malia Shitabata 1F
Sat Feb 08, 2020 8:15 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Example 4D.1
Replies: 1
Views: 37

Example 4D.1

For the example in the textbook, when calculating ∆H why do you divide 2 mol by 1.45x10^-3 mol? If there's 2 mol C6H6, shouldn't you multiply 2 by 1.45x10^-3? Can someone explain this please?
by Malia Shitabata 1F
Sat Feb 08, 2020 6:17 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: Molar internal energy (4B.3A) [ENDORSED]
Replies: 1
Views: 68

Molar internal energy (4B.3A) [ENDORSED]

Can someone walk me through this problem? I'm not sure I understand molar internal energy properly because I'm not getting the right answer when I plug it in:

Estimate the contribution of motion to the molar internal energy of water vapor at 25 ºC.
by Malia Shitabata 1F
Fri Feb 07, 2020 3:36 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: ∆S for summation
Replies: 3
Views: 36

∆S for summation

Can someone reexplain what Dr. Lavelle meant by ∆S being unnecessary when he was discussing calculating ∆Gº using standard enthalpy of formation and standard molar entropy values?
∆Sºrxn=∑Sºm(products)-∑Sºm(reactants)
by Malia Shitabata 1F
Thu Feb 06, 2020 9:27 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Positive ∆S
Replies: 5
Views: 40

Positive ∆S

If ∆S>0 can we assume a reaction is spontaneous?
by Malia Shitabata 1F
Wed Feb 05, 2020 5:41 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: qp=nCp∆T
Replies: 1
Views: 22

qp=nCp∆T

For calorimetry at constant pressure, why does pq equal ∆H?
by Malia Shitabata 1F
Wed Feb 05, 2020 5:21 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: Microstates
Replies: 7
Views: 49

Microstates

Can someone explain microstates and degeneracy to me because I'm not understanding it conceptually? Like what would you use it for?
by Malia Shitabata 1F
Wed Feb 05, 2020 5:19 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Increasing entropy
Replies: 1
Views: 16

Increasing entropy

If V2 is greater than V1, can we assume the reaction is spontaneous even without calculating ∆S?
by Malia Shitabata 1F
Sat Feb 01, 2020 11:10 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 4C.9
Replies: 1
Views: 15

4C.9

Calculate the heat that must be supplied to a copper kettle of mass 500.0 g containing 400.0 g of water to raise its temperature from 22.0 ºC to the boiling point of water, 100.0 ºC. What percentage of the heat is used to raise the temperature of the water? I calculated the initial heat that needs t...
by Malia Shitabata 1F
Thu Jan 30, 2020 9:39 pm
Forum: Calculating Work of Expansion
Topic: w=-P∆V
Replies: 2
Views: 30

w=-P∆V

Is w=-P∆V only used for irreversible processes?
by Malia Shitabata 1F
Thu Jan 30, 2020 5:07 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Equipartition Theorem
Replies: 2
Views: 20

Equipartition Theorem

Do we have to understand how to calculate the contributions to internal energy using the equipartition theorem? Because Professor Lavelle didn't go over that, but it's in the textbook focus that we have to read for this section.
by Malia Shitabata 1F
Thu Jan 30, 2020 4:41 pm
Forum: Calculating Work of Expansion
Topic: Reversible Reactions
Replies: 2
Views: 19

Re: Reversible Reactions

Clara Cho 2K wrote:The reaction is at equilibrium.

So how does that work in terms of heat?
by Malia Shitabata 1F
Thu Jan 30, 2020 1:14 pm
Forum: Calculating Work of Expansion
Topic: Reversible Reactions
Replies: 2
Views: 19

Reversible Reactions

What does it mean when a process is reversible?
by Malia Shitabata 1F
Thu Jan 30, 2020 12:52 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Delta X and U
Replies: 1
Views: 21

Delta X and U

What is the difference between X and U because it seems like they're related
by Malia Shitabata 1F
Tue Jan 28, 2020 6:07 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Closed vs isolated systems
Replies: 24
Views: 116

Closed vs isolated systems

Can somebody explain the difference between closed and isolated systems? I don't really understand the difference based off of the textbook definitions.
by Malia Shitabata 1F
Sat Jan 25, 2020 7:08 pm
Forum: Phase Changes & Related Calculations
Topic: Reading?
Replies: 5
Views: 38

Re: Reading?

The syllabus has the focus sections for each topic we are learning, so for "Thermochemistry and the First Law of Thermodynamics," it's 4A-4D.5 and 4E3.
by Malia Shitabata 1F
Sat Jan 25, 2020 7:05 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond enthalpies of diatomic molecules
Replies: 2
Views: 18

Bond enthalpies of diatomic molecules

In class, Dr. Lavelle said bond enthalpies of diatomic molecules are accurate. What is the relevance of this ie where does it come into play when solving equations? I'm confused because he also said calculating reaction enthalpies from the bond enthalpies is also the least accurate method.
by Malia Shitabata 1F
Fri Jan 24, 2020 9:46 pm
Forum: Phase Changes & Related Calculations
Topic: Endothermic values
Replies: 5
Views: 32

Endothermic values

For an endothermic reaction, delta H is positive. Do we have to write the plus sign for the value? Would it be wrong if we just left it out?
by Malia Shitabata 1F
Fri Jan 24, 2020 9:43 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Using different methods
Replies: 4
Views: 31

Using different methods

When do you know when to use certain methods of reaction enthalpies? Because method 2 (bond enthalpies) was the most inaccurate so should we just never use it?
by Malia Shitabata 1F
Fri Jan 24, 2020 9:40 pm
Forum: Phase Changes & Related Calculations
Topic: Heat, energy, and work
Replies: 2
Views: 22

Heat, energy, and work

What's the difference between heat, energy, and work? Because I thought heat was like thermal energy but then work and heat are state properties but energy isn't.
by Malia Shitabata 1F
Sun Jan 19, 2020 3:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6B.11 part a ii
Replies: 1
Views: 19

6B.11 part a ii

A student added solid Na2O to a volumetric flask of volume 200.0 mL which was then filled with water resulting in 200.0 mL of NaOH solution. Then 5.00 mL of the solution was transferred to another volumetric flask and diluted to 500.0 mL. The pH of the diluted solution is 13.25. What is the molar co...
by Malia Shitabata 1F
Sun Jan 19, 2020 3:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Volume and pressure
Replies: 4
Views: 33

Re: Volume and pressure

If you increase the pressure, the volume decreases. You can think about it in terms of the ideal gas law PV=nRT.
by Malia Shitabata 1F
Sat Jan 18, 2020 11:29 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6B.9
Replies: 3
Views: 28

6B.9

For the fill in the table, the first row with 1.50 mol/L given for [H3O+], I got a negative pH when I did pH=-log(1.50) but the solution manual says the pH is positive. Did I do something wrong or is that a typo?
by Malia Shitabata 1F
Sat Jan 18, 2020 1:39 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pH sig figs
Replies: 5
Views: 55

pH sig figs

When you have pOH and you're trying to find the pH should the pH have the same number of decimal places as the pOH? For example, if your pOH is 2.735 would you subtract from 14 or 14.000 or something in between? Because I feel like if you subtract from 14 and round based on decimal places then it ca...
by Malia Shitabata 1F
Tue Jan 14, 2020 2:43 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6D.3
Replies: 1
Views: 41

6D.3

When the pH of 0.10 M HClO2 (aq) was measured, it was found to be 1.2. What are the values of Ka and pKa of chlorous acid? I got the molarity of H3O+ through the pH but the solution manual says [H3O+]=[ClO2-]. If everything is in a 1:1 mole ratio, why isn't [ClO2-] 0.10 M like the HClO2? Also when p...
by Malia Shitabata 1F
Mon Jan 13, 2020 11:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6B.3
Replies: 2
Views: 18

Re: 6B.3

For part a since you're just doing the initial pH it's just based on the molarity so you do -log(0.025). For part b, find the moles using the molarity and the initial volume of 200.0 and then divide by the volume you actually ended up using to find the molarity of the used solution. Then find -log o...
by Malia Shitabata 1F
Mon Jan 13, 2020 7:06 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kw and H3O/OH concentrations
Replies: 5
Views: 26

Kw and H3O/OH concentrations

For water, is [H3O+] always equal to [OH-]? Because in class Professor Lavelle was saying they're both 1.0x10^-7 which is why Kw is 1.0x10^-14, but the book also mentions the see saw behavior when there's more H3O+, OH- concentration will decrease.
by Malia Shitabata 1F
Mon Jan 13, 2020 2:59 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Autoprotolysis
Replies: 6
Views: 31

Autoprotolysis

Does autoprotolysis only happen with water or can it be other molecules as well?
by Malia Shitabata 1F
Thu Jan 09, 2020 6:42 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.17
Replies: 3
Views: 38

Re: 5I.17

I'm not sure how you got x=0.0114, but if you plug in all the values into the K c ratio so that it's 1.00*10 -5 =(2x) 2 /((0.114-x)(0.114-x)) and solve for x using the quadratic formula, you should get x=1.8*10 -4 . I did 1.00x10^-5=(2x)^2/(0.114)^2 instead of (0.114-x)(0.114-x) for the denominator...
by Malia Shitabata 1F
Thu Jan 09, 2020 6:05 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.17
Replies: 3
Views: 38

5I.17

The equilibrium constant Kc for the reaction N2(g) + O2 (g) \rightleftharpoons 2NO (g) at 1200ºC is 1.00x10^-5. Calculate the equilibrium molar concentrations of NO, N2, and O2 in a reaction vessel of volume 1.00 L that initially held 0.114 mol N2 and 0.114 mol O2. I set up the ICE table with all th...
by Malia Shitabata 1F
Thu Jan 09, 2020 12:23 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5I.33
Replies: 2
Views: 41

5I.33

A sample of ammonium carbamate, NH4(NH2CO2) of mass 25.0 g was placed in an evacuated flask of volume 0.250 L and kept at 25ºC. At equilibrium, 17.4 mg of CO2 was present. What is the value of Kc for the decomposition of ammonium carbamate into ammonia and carbon dioxide? The reaction is NH4(NH2CO2)...
by Malia Shitabata 1F
Tue Jan 07, 2020 2:34 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Writing expression for K
Replies: 5
Views: 65

Re: Writing expression for K

You can use partial pressures when all the reactants and products of a reaction are in the gas phase and when the units are in the gas phase (bar, atm, mmHg, Torr, etc). You normally use concentrations when other phases other than the gas phase are involved in the reaction, and you can use PV=nRT t...
by Malia Shitabata 1F
Mon Jan 06, 2020 5:27 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Effect on the equilibrium constant
Replies: 2
Views: 37

Effect on the equilibrium constant

The textbook says the equilibrium constant value is only changed by varying the temperature. How come changing other physical conditions like pressure or volume don't affect the equilibrium constant?
by Malia Shitabata 1F
Mon Jan 06, 2020 5:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Writing expression for K
Replies: 5
Views: 65

Writing expression for K

When a question asks you to write an expression for K, how do you know when to use Px or [X]?
by Malia Shitabata 1F
Sat Dec 07, 2019 5:55 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pKA values
Replies: 4
Views: 55

Re: pKA values

pKa = -log[Ka] and it's the weak acid equilibrium constant. It's important to know so you can determine which acid is stronger/weaker when given its value. Ka and pKa have an inverse relationship. So a strong acid would have a high Ka value but a low pKa value. Conversely, a weak acid would have a l...
by Malia Shitabata 1F
Sat Dec 07, 2019 5:50 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Pka and Ph
Replies: 2
Views: 38

Re: Pka and Ph

pH equals pKa at the equivalence point, but I don't think that necessarily means the solution is neutral. When pH is less than pKa, the conditions are acidic enough for an acid to be protonated as HA.
by Malia Shitabata 1F
Sat Dec 07, 2019 5:30 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka for strong/weak acids
Replies: 2
Views: 30

Ka for strong/weak acids

Is Ka given if it's a strong or a weak acid? Because for some reason on one of my notes I wrote Ka is never given for a weak acid, but on another I wrote if it's given it's for a weak acid and now I'm not sure which one is correct.
by Malia Shitabata 1F
Sat Dec 07, 2019 1:22 pm
Forum: *Stereochemistry
Topic: Various Isomers
Replies: 1
Views: 60

Various Isomers

How do stereoisomers differ from geometrical isomers? The definitions sound very similar.
by Malia Shitabata 1F
Fri Dec 06, 2019 3:42 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Resonance
Replies: 3
Views: 72

Re: Resonance

So does this increase acidity strength or decrease it?
by Malia Shitabata 1F
Fri Dec 06, 2019 3:28 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Resonance
Replies: 3
Views: 72

Resonance

Resonance spreads the delocalized charge over more atoms and increases stability. Does this mean that if a molecule has resonance it's a weaker atom since the bonds will be more stable and take more energy to break?
by Malia Shitabata 1F
Fri Dec 06, 2019 3:11 pm
Forum: Biological Examples
Topic: Porphyrin
Replies: 1
Views: 40

Porphyrin

Porphyrin is characterized by a tentradentate square planar formation of 4 nitrogen atoms. Does the central atom have to be a transition metal or can it be any other element?
by Malia Shitabata 1F
Thu Dec 05, 2019 10:24 pm
Forum: Biological Examples
Topic: Cisplatin bonding in 2 places
Replies: 3
Views: 51

Cisplatin bonding in 2 places

Cisplatin can bond in 2 places because the chlorine atoms are easily displaced. Does this mean it chelates when it bonds with DNA?
by Malia Shitabata 1F
Wed Dec 04, 2019 9:46 pm
Forum: Hybridization
Topic: Pi bonds
Replies: 1
Views: 33

Pi bonds

Can someone explain the relationship between hybridization and pi bonds?
by Malia Shitabata 1F
Wed Dec 04, 2019 9:45 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka and Kb
Replies: 3
Views: 42

Ka and Kb

For polyprotic acids, Ka1 is always greater than Ka2 and the first step is always the stronger acid. Does the same go for Kb? Would Kb1 be greater than Kb2 and the first step indicate the stronger base?
by Malia Shitabata 1F
Wed Dec 04, 2019 9:42 pm
Forum: Naming
Topic: Cation Order
Replies: 1
Views: 26

Cation Order

If we're given the name of a coordination compound and asked to write the formula for it, does it mater what order we write the cations in? Because how would you be able to tell unless we're supposed to write them alphabetically?
by Malia Shitabata 1F
Sat Nov 30, 2019 10:07 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 3
Views: 22

Polydentate

So a ligand is polydentate if it can bond multiple regions to the central atom. So does this mean it's based off of the lone pairs or is it something else?
by Malia Shitabata 1F
Sat Nov 30, 2019 3:26 pm
Forum: Naming
Topic: Iron
Replies: 1
Views: 26

Iron

How do you know when to name a complex with iron in it as iron or ferrate? Because in the toolbox 9C.1 in the textbook, [FeCl(OH2)5]^+ is pentaaquachloridoiron(II) ion while [Fe(CN)6]^4- is hexacyanidoferrate(II) ion but both cases have iron as the central atom.
by Malia Shitabata 1F
Sat Nov 30, 2019 2:10 pm
Forum: Naming
Topic: Water
Replies: 1
Views: 37

Water

When do we use aqua vs dihydrogen/dihydrate when H2O is present in a molecule?
by Malia Shitabata 1F
Sat Nov 30, 2019 1:56 pm
Forum: Naming
Topic: -ate
Replies: 1
Views: 28

-ate

If a complex compound has a negative charge, we are supposed to add ate to the ending of the metal name. Do we do the same if it's a positive charge or do we not add anything?
by Malia Shitabata 1F
Fri Nov 29, 2019 5:12 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: triple equal sign
Replies: 2
Views: 34

triple equal sign

I'm not really sure what to call it but what does the equal sign but with three lines mean? I wrote that pKA=-log[KA] in my notes and that p=-log except that for the p equation the equal sign had 3 lines. Was this just a typo or does it have a significance?
by Malia Shitabata 1F
Fri Nov 22, 2019 12:23 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Transplatin
Replies: 3
Views: 32

Transplatin

I understand why cisplatin is an effective chemotherapy drug, but can someone reexplain why transplatin isn't? I don't think I copied it down correctly in lecture.
by Malia Shitabata 1F
Wed Nov 20, 2019 1:22 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 4
Views: 52

Ligands

Can ligands be a central atom if the central atom has a lone pair or does it always have to be a surrounding atom the central atom is bonded to?
by Malia Shitabata 1F
Wed Nov 20, 2019 1:19 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 4
Views: 61

Re: Cisplatin

So because it is a cis molecule the two chlorine atoms are on the same side of the cisplatin molecule. As a result, when one chlorine bonds the other can be displaced so the compound can be bound in 2 places which makes the bonds stronger. This blocks DNA replication from occurring so cell division ...
by Malia Shitabata 1F
Wed Nov 20, 2019 1:16 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Compound Arrangement
Replies: 2
Views: 32

Compound Arrangement

For the [NiCl2(NH3)4] example from class why are some of the ammonia atoms written backwards how do we know when to write them backwards?
by Malia Shitabata 1F
Tue Nov 19, 2019 1:40 pm
Forum: Hybridization
Topic: Degenerate Orbitals
Replies: 1
Views: 25

Degenerate Orbitals

In the problem that we did in class with methane CH4 the sp^3 hybridization was made using degenerate orbitals. Do we always use degenerate orbitals when doing hybridization?
by Malia Shitabata 1F
Sun Nov 17, 2019 9:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Electronic arrangement vs molecular shape
Replies: 4
Views: 19

Re: Electronic arrangement vs molecular shape

So would the actual bond angle be closer to the shape obtained from the electronic arrangement or the molecular shape?
by Malia Shitabata 1F
Sun Nov 17, 2019 6:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Electronic arrangement vs molecular shape
Replies: 4
Views: 19

Electronic arrangement vs molecular shape

I'm a little confused what the difference between electronic arrangement and molecular shape is since VSEPR rule 3 says only positions of atoms count toward molecular shape. Can someone explain this in simpler terms?
by Malia Shitabata 1F
Sun Nov 17, 2019 5:53 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizable vs polarizing power
Replies: 5
Views: 84

Polarizable vs polarizing power

Is polarizability only used to describe anions and polarizing power only for cations? And if so, does this imply that anions have no polarizing power and cations are not polarizable?
by Malia Shitabata 1F
Sun Nov 17, 2019 5:01 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lewis Structure Representation
Replies: 1
Views: 25

Lewis Structure Representation

For the Lewis structure representation using the dashed and thick lines to indicate which plane each atom is in, is there any way to indicate double and triple bonds or is it only for single bonds? Also is there a name for this model?
by Malia Shitabata 1F
Wed Nov 13, 2019 10:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 2
Views: 34

Bond Angles

For a molecule with a trigonal planar shape, how do we know if it's 120º, less than 120º, or 109.5º?
by Malia Shitabata 1F
Wed Nov 13, 2019 10:06 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E #5
Replies: 4
Views: 53

2E #5

What is the shape of a ClO2+ ion and what is the expected bond angle?

The solution manual says it is trigonal planar, but how come it's not a linear shape if Cl is only bonded to two other atoms? And if it's trigonal planar, why would the bond angles be slightly less than 120º?
by Malia Shitabata 1F
Wed Nov 06, 2019 2:19 pm
Forum: Properties of Light
Topic: Rydberg Equation
Replies: 5
Views: 122

Re: Rydberg Equation

I think we need to know that the energy level starts from n=1 for Lyman series(UV region) and it starts from n=2 for Balmer series(visible region, 700nm-400nm). If a higher frequency is associated with greater energy then why is Balmer n=2 even though visible light has a lower frequency than ultrav...
by Malia Shitabata 1F
Wed Nov 06, 2019 12:16 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 2A #21
Replies: 1
Views: 52

2A #21

Give the ground state electron configuration and number of unpaired electrons expected for each of the following ions: Ag+ The answer in the solutions manual was [Kr]4d^{10} but the answer I got was [Kr]4d^8 because I thought you would subtract the electron since the charge is positive? But the elec...
by Malia Shitabata 1F
Tue Nov 05, 2019 7:35 pm
Forum: Coordinate Covalent Bonds
Topic: Coordinate vs polar covalent
Replies: 6
Views: 117

Coordinate vs polar covalent

How does a coordinate covalent bond differ from a polar covalent bond?
by Malia Shitabata 1F
Tue Nov 05, 2019 7:33 pm
Forum: Properties of Light
Topic: Rydberg Equation
Replies: 5
Views: 122

Rydberg Equation

Do we have to understand the Balmer/Lyman series in relation to n and the Rydberg equation or should we just know which portion of the electromagnetic spectrum it corresponds to?
by Malia Shitabata 1F
Tue Nov 05, 2019 7:30 pm
Forum: Properties of Electrons
Topic: Mass of an electron
Replies: 9
Views: 142

Mass of an electron

Do we have to memorize the mass of an electron since it's a constant or will it be given on the reference sheet?
by Malia Shitabata 1F
Sun Nov 03, 2019 7:07 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Stability
Replies: 3
Views: 52

Re: Formal Charge Stability

Also when assigning formal charge values, if there is a negative value it is most stable if it goes on the more electronegative atom.
by Malia Shitabata 1F
Sat Nov 02, 2019 7:40 pm
Forum: Electronegativity
Topic: Figuring it out without the trend?
Replies: 4
Views: 46

Re: Figuring it out without the trend?

Electronegativity is how likely an atom is to attract an electron into its orbital so you can also think of it in terms of the attractive forces between the protons and electrons and how easy it is for an electron to complete an orbital and make an atom stable.
by Malia Shitabata 1F
Sat Nov 02, 2019 7:36 pm
Forum: Electronegativity
Topic: which bond
Replies: 4
Views: 57

Re: which bond

If we're being super specific, if the electronegativity difference is <2 it is a polar covalent bond and if the electronegativity difference is 0 it is a covalent bond. This designates if it's a bond shared between two of the same element ie C-C (covalent) or different elements ie C-H (polar covalen...
by Malia Shitabata 1F
Sat Nov 02, 2019 2:42 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Degenerate orbitals
Replies: 4
Views: 60

Degenerate orbitals

Can somebody explain what degenerate orbitals are? They mentioned it during the review session yesterday, but I was a little confused
by Malia Shitabata 1F
Tue Oct 29, 2019 10:53 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 2A #5
Replies: 4
Views: 42

Re: 2A #5

Thanks! And do we always write the 3 level before the 4 because I thought it was only for chromium and copper?
by Malia Shitabata 1F
Tue Oct 29, 2019 9:59 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 2A #5
Replies: 4
Views: 42

2A #5

Give the ground state electron configuration for Cu+ ion. The solutions manual says the answer is [Ar]3d^10 but I wrote out the full electron configuration as 1s^22s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{8} which still has the same number of electrons. Am I still right even though they end on two different...

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