Search found 30 matches
- Sun Mar 18, 2018 3:14 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capacity of Water
- Replies: 4
- Views: 778
Re: Heat Capacity of Water
the hydrogen bonds are very difficult to break so therefore it has a high heat capacity because it reuqires a lot of energy to break these bonds
- Sun Mar 18, 2018 3:12 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Is enthalpy a state function?
- Replies: 12
- Views: 2228
Re: Is enthalpy a state function?
yes it is
- Sun Mar 18, 2018 3:12 pm
- Forum: Phase Changes & Related Calculations
- Topic: Steam
- Replies: 7
- Views: 1229
Re: Steam
water is at a higher temp when it is steam, so therefore it would cause a more severe burn
- Sun Mar 11, 2018 10:39 pm
- Forum: Balancing Redox Reactions
- Topic: Test #2
- Replies: 4
- Views: 764
Re: Test #2
K>1 means its spotaneous, essentially its the opposite of delta g.
- Sun Mar 11, 2018 10:38 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation Number
- Replies: 4
- Views: 542
Re: Oxidation Number
finding the oxidation of a molecule that isn't standard depends entirely upon the the oxidation number of the molecule with standard oxidation values, like O and H. they usually have to equal each other, so just make sure the charges cancel out. hope that makes sense
- Sun Mar 11, 2018 10:36 pm
- Forum: Balancing Redox Reactions
- Topic: Ranking elements
- Replies: 8
- Views: 1185
Re: Ranking elements
the more negative the number, the higher reducing potential that element has. You would be given the values and just rank them from that.
- Sat Mar 03, 2018 11:55 pm
- Forum: Second Order Reactions
- Topic: Half-life of Second-Order
- Replies: 2
- Views: 1693
Re: Half-life of Second-Order
it is definitely correct and useable, so I'm not really sure why it would say don't use it. Maybe we won't be asked this question often.
- Sat Mar 03, 2018 11:53 pm
- Forum: First Order Reactions
- Topic: Naming Orders
- Replies: 3
- Views: 563
Re: Naming Orders
I think individually the orders are first, and together they form a second order reaction.
- Sat Mar 03, 2018 11:51 pm
- Forum: First Order Reactions
- Topic: k
- Replies: 16
- Views: 1650
Re: k
The units of k are completely dependent on what order you are dealing with. Zero order is M/s, first order is in s^-1, and second order is L/mol●s
- Mon Feb 26, 2018 9:39 am
- Forum: General Rate Laws
- Topic: Rate of Reaction
- Replies: 4
- Views: 560
Re: Rate of Reaction
you just need to pay attention to the coefficients, and since o2 is half, theres half as much made
- Mon Feb 26, 2018 9:38 am
- Forum: General Rate Laws
- Topic: Reaction Rates [ENDORSED]
- Replies: 2
- Views: 360
Re: Reaction Rates [ENDORSED]
I think that since its moving forward creating products, is why its positive.
- Mon Feb 26, 2018 9:36 am
- Forum: General Rate Laws
- Topic: rate constants
- Replies: 7
- Views: 904
Re: rate constants
I'm also a little confused on the concept of K. In our notes it says K is dependent on temperature and activation energy. So if it's dependent, how is it a constant?
- Fri Feb 16, 2018 2:30 pm
- Forum: Balancing Redox Reactions
- Topic: Salt Bridge Versus Pourous Disk
- Replies: 6
- Views: 814
Salt Bridge Versus Pourous Disk
I was wondering if using a porous disk or a salt bridge made the reaction different, and what that difference is. Thank you!
- Fri Feb 16, 2018 2:27 pm
- Forum: Balancing Redox Reactions
- Topic: Salt Bridges
- Replies: 14
- Views: 1349
Re: Salt Bridges
Salt bridges are used to transfer electrons that have already passed from the anode, to the cathode, back to the anode. This maintains equilibrium in the battery and allows it to not “die” as fast.
- Fri Feb 16, 2018 2:25 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell diagram acidic/basic
- Replies: 3
- Views: 425
Re: Cell diagram acidic/basic
Yes because since you are using both those specific methods, you have to add either OH or H+ to signify that.
- Mon Feb 12, 2018 2:13 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Delta S total [ENDORSED]
- Replies: 2
- Views: 443
Re: Delta S total [ENDORSED]
ΔSsys+Δsurroundings =Δtotal, so when ΔS total=0, you just move either ΔS sys or ΔSsurr to the other side, making one negative. It doesn't matter which one
- Mon Feb 12, 2018 2:05 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Cp v. Cv!
- Replies: 5
- Views: 825
Re: Cp v. Cv!
You use Cp when there is constant pressure and Cv when you are delaing with constant volume
- Mon Feb 12, 2018 12:52 pm
- Forum: Phase Changes & Related Calculations
- Topic: Reversible
- Replies: 5
- Views: 1125
Reversible
Can someone please explain to me the difference between what reversible and irreversible and how it’s improtnst to understanding a question! Thanks!
- Sun Feb 04, 2018 11:01 pm
- Forum: Phase Changes & Related Calculations
- Topic: enthalpy and entropy when it comes to spontaneous reactions
- Replies: 6
- Views: 774
Re: enthalpy and entropy when it comes to spontaneous reactions
the value of temperature plays a great deal into the spontaneity of the reaction. The sign of the delta H and the delta also influences the ultimate sign of delta G, so it is somewhat a case to case basis. Neither one over the other influences it more.
- Sun Feb 04, 2018 10:52 pm
- Forum: Phase Changes & Related Calculations
- Topic: Degeneracy
- Replies: 4
- Views: 637
Re: Degeneracy
these are all correct, but the way that I find it easiest to remember it is basically the different ways we can arrange particles
- Sun Feb 04, 2018 10:47 pm
- Forum: Phase Changes & Related Calculations
- Topic: The universe
- Replies: 9
- Views: 1112
Re: The universe
The universe is isolated because we consider it to be everything in existence, therefore it cannot lose energy or matter to anything else.
- Sun Jan 28, 2018 10:22 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond Enthalpies
- Replies: 7
- Views: 830
Re: Bond Enthalpies
The stronger the bonds, the more energy it takes to require to break the bonds, therefore having a higher bond enthalpy.
- Sun Jan 28, 2018 10:19 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Question regarding 8.39 homework question
- Replies: 5
- Views: 623
Re: Question regarding 8.39 homework question
The way I like to think of it is that you want to use the specific heat of the phase that it is changing into, as long as you're temperature threshold does not cross between two phases. This would do this if the problem would have started with -1 degree celsius. Hope that helps!
- Sun Jan 28, 2018 10:16 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Question 8.31
- Replies: 7
- Views: 1042
Re: Question 8.31
Since you add 273 to both values, it would not interfere with the delta T value.
- Sun Jan 21, 2018 5:13 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: 8.67
- Replies: 3
- Views: 370
Re: 8.67
For this, I'm also confused how you are supposed to combine the use of bond enthapies and also the enthalpy of formations.
- Sun Jan 21, 2018 5:08 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: delta U and delta h
- Replies: 1
- Views: 363
delta U and delta h
I'm confused how delta U is related to delta H, also if this will be on the upcoming test. Thanks!
- Sun Jan 21, 2018 5:05 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Heat versus work
- Replies: 6
- Views: 826
Heat versus work
I'm confused on what I need to know, relevently, about the difference between work and heat. I know that heat is the energy associated with the random motion of particles, and work is energy of ordered motion in one direction, but I'm still confused as to what that really means. Thanks in advance!
- Sun Jan 14, 2018 12:08 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Calorimeter
- Replies: 10
- Views: 1071
Calorimeter
Can someone explain to me the importance and function of a calorimeter? Is this something that will be a big topic in our upcoming problems?
- Sun Jan 14, 2018 12:06 pm
- Forum: Phase Changes & Related Calculations
- Topic: Why can state properties be added?
- Replies: 11
- Views: 1302
Re: Why can state properties be added?
As stated before, state properties do not depend on the path taken, and therefore because they’re independent of this, we can add them together.
- Sat Jan 13, 2018 8:30 pm
- Forum: Calculating Work of Expansion
- Topic: Work (in general) [ENDORSED]
- Replies: 4
- Views: 456
Work (in general) [ENDORSED]
How do you know which work equation to use?