Search found 30 matches
- Tue Mar 12, 2019 3:12 pm
- Forum: Second Order Reactions
- Topic: amounts of reactant and its affect on rate
- Replies: 6
- Views: 573
Re: amounts of reactant and its affect on rate
yes, and it all comes down the the ^2 in the rate equation of a second order reaction
- Tue Mar 12, 2019 3:10 pm
- Forum: Calculating Work of Expansion
- Topic: Work
- Replies: 8
- Views: 952
Re: Work
most of the equations will be given to us on the equation sheet, and it is important to know which one to use in a given situation
- Tue Mar 12, 2019 3:08 pm
- Forum: General Rate Laws
- Topic: slow step
- Replies: 11
- Views: 1424
Re: slow step
the k value is the rate constant in the rate equation, so if the rate constant is small, then the rate is slow
- Tue Mar 12, 2019 3:07 pm
- Forum: Ideal Gases
- Topic: Approximations for ICE
- Replies: 20
- Views: 1640
Re: Approximations for ICE
when k is less than 10^-3, then we can assume that x is small enough to not have an effect in the math
- Tue Mar 12, 2019 3:05 pm
- Forum: Phase Changes & Related Calculations
- Topic: joules conversion factor
- Replies: 7
- Views: 1061
Re: joules conversion factor
its on the equation sheet. just make sure to leave the answer in whatever unit the question specifies
- Tue Mar 12, 2019 3:04 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: internal energy
- Replies: 3
- Views: 399
Re: internal energy
isothermal reactions have a deltaU of 0. not sure about reversible or irreversible
- Tue Feb 26, 2019 1:15 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Change in enthalpy
- Replies: 2
- Views: 394
Re: Change in enthalpy
it doesn't always favor the reverse reaction. When enthalpy is positive and entropy is negative, then the reaction favors the reverse. However when enthalpy is positive and entropy is also positive, the sign of Delta G depends on the temperature. You would use the equation "DeltaG= DeltaH - T(D...
- Tue Feb 26, 2019 1:11 am
- Forum: Balancing Redox Reactions
- Topic: redox potential
- Replies: 1
- Views: 206
Re: redox potential
when K, the equilibrium constant, is 1
- Tue Feb 26, 2019 1:09 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 2
- Views: 278
Re: Cell Diagrams
they are the same states
- Mon Feb 25, 2019 11:59 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Voltaic vs galvanic cell
- Replies: 2
- Views: 295
Re: Voltaic vs galvanic cell
i'm pretty sure they are interchangeable. not 100% though
- Mon Feb 25, 2019 11:57 pm
- Forum: Balancing Redox Reactions
- Topic: OH or H20
- Replies: 2
- Views: 318
Re: OH or H20
when balancing half reactions, h20 will generally be used to balance oxygen, but when in a basic environment, OH should then be used to balance the excess hydrogen
- Mon Feb 25, 2019 12:46 am
- Forum: Balancing Redox Reactions
- Topic: balancing redox reactions
- Replies: 2
- Views: 348
Re: balancing redox reactions
the important thing is to balance any non hydrogen or oxygen first, and then balance oxygen with H20. Then balance the hydrogen with protons (H+). then balance the charges with electrons. once you add the equations back, you can cancel opposing charges in an acidic environment. There is an extra ste...
- Mon Feb 25, 2019 12:30 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Spontaneous?
- Replies: 13
- Views: 1588
Re: Spontaneous?
with a negative deltaG, it indicates that the second state of the reaction, in other words the products, are favored so therefore the reaction is spontaneous
- Mon Feb 25, 2019 12:20 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: What is E?
- Replies: 4
- Views: 445
Re: What is E?
the standard reaction potentials of say a copper zinc (Cu/Zn) battery can be used to find the voltage of the battery. given the standard reaction potentials of the components of the redox reaction, you would add and subtract based on whether they are products or reactants to find the voltage. A posi...
- Mon Feb 25, 2019 12:15 am
- Forum: Van't Hoff Equation
- Topic: When to apply the Van't Hoff Equation
- Replies: 5
- Views: 747
Re: When to apply the Van't Hoff Equation
the Van't Hoff equation can be used to find the equilibrium constant of the reaction while the gibb's free energy equation can be used to find deltaG, which can then determine if the reaction is spontaneous or not
- Mon Feb 25, 2019 12:12 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Spontaneous and unstable
- Replies: 4
- Views: 1552
Re: Spontaneous and unstable
spontaneous refers to the deltaG being negative in a reaction, which means that the reaction is product favored. not 100% sure how this is any different from an unstable reaction
- Thu Feb 21, 2019 10:33 am
- Forum: Balancing Redox Reactions
- Topic: Week 7 Homework
- Replies: 15
- Views: 1247
Re: Week 7 Homework
gibbs free energy and maybe explore electrochem more
- Thu Feb 21, 2019 10:31 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Pt as an electrode
- Replies: 4
- Views: 635
Re: Pt as an electrode
Platinum is an inert electrode which means it will not interfere or react with the chemical redox reaction and skew results
- Thu Feb 21, 2019 8:25 am
- Forum: Balancing Redox Reactions
- Topic: Weekly Homework
- Replies: 3
- Views: 405
Re: Weekly Homework
on the syllabus there is a list of book problems under the section they correspond with. Each week you have to choose 7 do complete and turn in during your discussion session
- Thu Feb 21, 2019 8:23 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy Meaning
- Replies: 6
- Views: 752
Re: Gibbs Free Energy Meaning
When deltaG is negative, the reaction is spontaneous which means that under the current conditions, the reaction is favorable and will produce the products
- Thu Feb 21, 2019 8:20 am
- Forum: Phase Changes & Related Calculations
- Topic: heat of a phase change
- Replies: 5
- Views: 530
Re: heat of a phase change
Depending on what unit the question is asking for, you can use moles x delta H or mass x delta H.
- Wed Feb 13, 2019 3:25 pm
- Forum: Calculating Work of Expansion
- Topic: Change in moles
- Replies: 3
- Views: 391
Re: Change in moles
yes because delta nRT is an alteration of the ideal gas law
- Wed Feb 13, 2019 3:20 pm
- Forum: Administrative Questions and Class Announcements
- Topic: breakdown of midterm?
- Replies: 4
- Views: 429
Re: breakdown of midterm?
probably gonna be equilibrium and acid/base for about half and thermo for the other half
- Wed Feb 13, 2019 3:18 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Heat and Entropy
- Replies: 3
- Views: 379
Re: Heat and Entropy
multiple steps allow you to figure out the values all components necessary to use the formula
- Wed Feb 13, 2019 3:16 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Ideal Gases
- Replies: 2
- Views: 344
Re: Ideal Gases
ideal gases assume all contact is completely elastic, which in a real gas is not true. This would have a slight effect on pressure so we use ideal gases simply because they are predictable and easy to work with
- Wed Feb 13, 2019 3:14 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Equations
- Replies: 3
- Views: 397
Re: Equations
any equations that involve enthalpy, internal energy, work, entropy, and heat. The ideal gas law as well
- Wed Feb 13, 2019 3:11 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: difference in states
- Replies: 6
- Views: 772
Re: difference in states
yes the different systems affect the temp and volume and the pressure etc.
- Mon Jan 28, 2019 10:45 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 4.C.3
- Replies: 1
- Views: 198
Re: 4.C.3
That is the gas constant for the units given.
- Sun Jan 13, 2019 6:49 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: affect change in pressure has on concentration
- Replies: 2
- Views: 142
Re: affect change in pressure has on concentration
I am not 100% sure what the question is, but i can clear up Le Chatelier's Principle when it comes to volume and pressure's effects on concentration. A change in pressure will not affect the equilibrium constant of the reaction, but it can change the direction that the reaction shifts. The pressure ...
- Sun Jan 13, 2019 6:37 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE Tables
- Replies: 2
- Views: 310
Re: ICE Tables
Often when posed a question where an ICE table is necessary, you will be given initial concentrations for either the reactants or the products. And as for using variables for the change, a reaction in equilibrium allows you to assume the change (lets call it "x") in reactants is the same a...