Search found 37 matches
- Thu Mar 07, 2019 11:49 am
- Forum: Second Order Reactions
- Topic: graph for second order
- Replies: 7
- Views: 792
Re: graph for second order
It is a linear line with a positive slope since k is positive.
- Thu Mar 07, 2019 11:48 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Pt
- Replies: 14
- Views: 1364
Re: Pt
If there is no solid present, then you can add in Pt to make the cell diagram.
- Thu Mar 07, 2019 11:47 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Ecell
- Replies: 13
- Views: 1499
Re: Ecell
Use the reduction potential of the Cathode and the Anode.
- Thu Mar 07, 2019 11:46 am
- Forum: Zero Order Reactions
- Topic: zero order rate?
- Replies: 14
- Views: 1604
Re: zero order rate?
Yes, it is independent of concentration.
- Thu Mar 07, 2019 11:46 am
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Study Advice
- Replies: 73
- Views: 7113
Re: Study Advice
One thing I do is that I go on the Syllabus and it lists practice problems for each topic. So i go over those and try to understand them conceptually.
- Thu Mar 07, 2019 11:44 am
- Forum: Experimental Details
- Topic: Final [ENDORSED]
- Replies: 4
- Views: 1496
Re: Final [ENDORSED]
No but it will help to kind of understand it. Just the basics of it
- Thu Mar 07, 2019 11:43 am
- Forum: Second Order Reactions
- Topic: pseudo-first-order reaction
- Replies: 4
- Views: 514
Re: pseudo-first-order reaction
It means that it can be first order with one of the reactants, but the overall order could be second order.
- Thu Mar 07, 2019 11:42 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: the phases in a cell diagram
- Replies: 4
- Views: 455
Re: the phases in a cell diagram
Aqueous in the middle and solids on the outside.
- Thu Mar 07, 2019 11:41 am
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: how is kinetics different?
- Replies: 17
- Views: 1675
Re: how is kinetics different?
Thermo deals with change in energy. Kinetics deals with change in rxn rates
- Thu Mar 07, 2019 11:40 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Galvanic Cells
- Replies: 4
- Views: 417
Re: Galvanic Cells
The reversibility of it makes energy and allows it to do work. If it were not reversible, there would be no production of energy.
- Thu Mar 07, 2019 11:39 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: E cell
- Replies: 5
- Views: 492
Re: E cell
E^o cell is used when under standard conditions. E cell is under "nonstandard" conditions.
- Thu Mar 07, 2019 11:38 am
- Forum: Balancing Redox Reactions
- Topic: Writing half reactions
- Replies: 7
- Views: 653
Re: Writing half reactions
You would put the H+ with the Cr2O7 since the oxygen atoms are balanced with H20, and the H20 is balanced with the H+
- Thu Mar 07, 2019 11:37 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Test 2 Gibbs Free Energy
- Replies: 5
- Views: 708
Re: Test 2 Gibbs Free Energy
Melting ice is a spontaneous reaction, and a negative Gibbs Free Energy indicates a spontaneous reaction.
- Thu Mar 07, 2019 11:36 am
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Units
- Replies: 4
- Views: 451
Re: Units
zero order: M/s
1st order: 1/s
2nd order : 1/(M*s)
1st order: 1/s
2nd order : 1/(M*s)
- Thu Mar 07, 2019 11:34 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst
- Replies: 6
- Views: 570
Re: Nernst
You can use either, but if you are converting between ln and log, use lnx=2.303logx
- Thu Mar 07, 2019 11:33 am
- Forum: Zero Order Reactions
- Topic: zero vs. first vs. second reactions
- Replies: 3
- Views: 336
Re: zero vs. first vs. second reactions
you could also always graph the data and see which one is linear and then compare it to the first and second order rxns
- Thu Mar 07, 2019 11:30 am
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Instantaneous vs Average
- Replies: 11
- Views: 1052
Re: Instantaneous vs Average
The average rate is the rate over a given interval of time. Instantaneous rate is the rate at a given moment in time
- Thu Mar 07, 2019 11:29 am
- Forum: Zero Order Reactions
- Topic: Order Reactions
- Replies: 4
- Views: 441
Re: Order Reactions
Yes. There are 3rd and 4th order reactions, but we don't need them for this class
- Thu Feb 07, 2019 11:51 am
- Forum: Calculating Work of Expansion
- Topic: Pressure Units
- Replies: 7
- Views: 779
Re: Pressure Units
I think as long as you know the conversions between torr, bar, and atm, you'll be fine. Although I am not sure if he will give the values on the test or not.
- Thu Feb 07, 2019 11:50 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Quiz 1 Number 3c
- Replies: 6
- Views: 670
Re: Quiz 1 Number 3c
you could write mol*L^-1 or M or mol/L
- Thu Feb 07, 2019 11:49 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: ΔH and ΔU
- Replies: 6
- Views: 879
Re: ΔH and ΔU
The degree symbolizes that it is occurring at standard conditions of 1atm. There can be instances where there is no degree symbol and that means that there is a change in the standard conditions.
- Thu Feb 07, 2019 11:46 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Adding Inert Gas
- Replies: 10
- Views: 4593
Re: Adding Inert Gas
Adding an inert gas does change the pressure, but since the change in pressure was not caused by a change in volume and since the inert gas does not have any effect on the reaction, there will be no change in equilibrium.
- Thu Feb 07, 2019 11:44 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Open vs Closed System
- Replies: 13
- Views: 4584
Re: Open vs Closed System
In an open system, there is a possibility for matter to exchange with the solution since it is open and matter can be exchanged with the surroundings. However, in a closed system, only energy can be exchanged since the system is closed so no matter can enter or exit.
- Thu Feb 07, 2019 11:43 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle
- Replies: 11
- Views: 1556
Re: Le Chatelier's Principle
If you look at partial pressure as concentrations, if you increase the partial pressure of the reactants, the reaction will favor the products. If you increase the partial pressure of the products, the reaction will favor the reactants.
- Thu Feb 07, 2019 11:41 am
- Forum: Administrative Questions and Class Announcements
- Topic: Week 5 Homework
- Replies: 3
- Views: 357
Re: Week 5 Homework
Yea. As long as we label it as what it is we are doing, it won't matter which ones you do
- Thu Feb 07, 2019 11:39 am
- 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 and Entropy
- Replies: 1
- Views: 254
Degeneracy and Entropy
Hey. I am still confused on the relation between Degeneracy and Entropy. Like if one increases does the other? Or how does the relationship work?
- Thu Feb 07, 2019 11:37 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Le Chateliers Priniciple
- Replies: 9
- Views: 938
Re: Le Chateliers Priniciple
Technically an increase in pressure will favor the side with less moles, but it also depends on other factors such as if it is an inert gas or if there is a change in volume with the reaction.
- Thu Feb 07, 2019 11:36 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Le Chateliers Priniciple
- Replies: 9
- Views: 938
Re: Le Chateliers Priniciple
If you increase the pressure, the reaction will favor the side with less moles.
- Thu Feb 07, 2019 11:31 am
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Negative q
- Replies: 7
- Views: 2778
Re: Negative q
A negative q signifies that the reaction is exothermic and that heat is being released with the reaction.
- Thu Feb 07, 2019 11:29 am
- Forum: Phase Changes & Related Calculations
- Topic: Solids and Liquids
- Replies: 5
- Views: 531
Re: Solids and Liquids
It is because you cannot compress a solid or liquid like you can to a gas. So therefore, the pressure and change in volume are negated since it won't make a difference.
- Sat Feb 02, 2019 5:32 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed vs isolated
- Replies: 14
- Views: 1080
Re: closed vs isolated
With a closed system, there is still an exchange of energy with the surroundings. But, with a sealed system, there is no exchange of energy or matter with the surroundings.
- Sat Feb 02, 2019 5:30 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Test Question
- Replies: 4
- Views: 478
Test Question
Just a quick question, would there be a difference in Kp and Kc if you are dealing with gases. Like, wouldn't both values be the same?
- Sat Feb 02, 2019 5:15 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: 3 methods for enthalpy calculation
- Replies: 10
- Views: 1976
Re: 3 methods for enthalpy calculation
Usually you would want to use either the enthalpy of formation or of combustion methods. These are the most accurate and easiest to use. Using the mean bond enthalpy is less accurate and it can get confusing at times. It really depends on what equations you are given and what values you know. There...
- Fri Feb 01, 2019 1:09 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: 3 methods for enthalpy calculation
- Replies: 10
- Views: 1976
Re: 3 methods for enthalpy calculation
Usually you would want to use either the enthalpy of formation or of combustion methods. These are the most accurate and easiest to use. Using the mean bond enthalpy is less accurate and it can get confusing at times. It really depends on what equations you are given and what values you know. There ...
- Thu Jan 24, 2019 11:33 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pH vs pKa
- Replies: 3
- Views: 375
Re: pH vs pKa
pKa is the -log(Ka value). pH is the -log(H3O+ concentration). If you are given the pH, you can use 10^-(pH value) and find your H3O+ concentration. Then you can set up an ice table and find the values at equilibrium and use those values to find the Ka value and pKa value.
- Thu Jan 24, 2019 11:19 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Composition
- Replies: 2
- Views: 261
Re: Equilibrium Composition
There may also be situations where you could just use the basic outline for a chemical equation (HA, H3O+, OH-) if you know how the reaction proceeds. This could help you save time and make the problem easier instead of spending too much time getting the equation correct.
- Thu Jan 24, 2019 11:15 am
- Forum: Amphoteric Compounds
- Topic: amphoteric v amphiprotic
- Replies: 5
- Views: 1149
Re: amphoteric v amphiprotic
Amphoteric means that the substance can act as either an acid or a base. Amphiprotic means that the the substance can both and accept donate hydrogen ions (aka protons). All amphiprotic substances are also amphoteric (donate hydrogen ions (act as an acid) or accept a hydrogen ion (act as a base)). B...