Search found 15 matches
- Wed Mar 14, 2018 1:32 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Minimum for a B-?
- Replies: 3
- Views: 281
Re: Minimum for a B-?
Is it though? Because on the syllabus it states that a C- = 50% (250pts), where as based on your calculations a C- = 350 pts which is why I’m confused...
- Tue Mar 13, 2018 6:59 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Minimum for a B-?
- Replies: 3
- Views: 281
Minimum for a B-?
Does anyone know the exact number of pts out of 500pts one needs to be able to get a B-?
- Tue Mar 13, 2018 6:31 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test Grading
- Replies: 4
- Views: 379
Test Grading
Quick question, did Lavelle say something about dropping our lowest Quiz score and replacing it with our highest as part of the grading or am I going crazy??? I swear I thought that he said something about that and now I have reread the syllabus like 5 times to try and see it in writing and I can't ...
- Sun Feb 18, 2018 8:27 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing
- Replies: 3
- Views: 230
Balancing
Just for reassurance, we DO have to use H2O to balance out the Oxygen in a reaction right? Then H+ for acidic solutions and OH- for basic right?
- Sun Feb 18, 2018 8:24 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing
- Replies: 3
- Views: 162
Re: Balancing
To add to the previous answer, let's say you have Ti^(+2) and its reduced to just Ti. The oxidation number in the first one is +2 and the oxidation number of the second one is 0, thus to balance there must be an addition of 2 electrons. So to visualize it: Ti^(+2) ------> Ti (our half reaction) +2 -...
- Sun Feb 18, 2018 8:14 pm
- Forum: Balancing Redox Reactions
- Topic: Addition of H3O+ or OH-
- Replies: 4
- Views: 239
Re: Addition of H3O+ or OH-
I think you might be confusing what to add at what point. You add H2O in order to balance out the number of O in a reaction and you either add H+ or OH- depending on what type of solution you're working with and as previously mentioned you do H for acidic solutions and OH of basic ones.
- Sat Feb 03, 2018 2:30 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Internal Energy in a Vacuum [ENDORSED]
- Replies: 5
- Views: 258
Re: Internal Energy in a Vacuum [ENDORSED]
Same applies if say a question was to mention something happening in space as well.
- Sat Feb 03, 2018 2:21 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Reversible systems
- Replies: 7
- Views: 334
Re: Reversible systems
Yep, you would find deltaS for the volume change, then the deltaS for the pressure change then add these values up to find deltaS total.
- Sat Feb 03, 2018 2:13 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Isobaric [ENDORSED]
- Replies: 3
- Views: 187
Re: Isobaric [ENDORSED]
So a friend mentioned a neat little way to remember the difference between isobaric, isometric/isochoric, and isothermal. For isobaric, focus on the 'baric' part. Think about 'bar' which is a unit of pressure. So when isobaric you know that the constant variable is pressure. For isometric, focus on ...
- Sat Jan 20, 2018 9:21 pm
- Forum: Calculating Work of Expansion
- Topic: Work done on / work done by system
- Replies: 5
- Views: 221
Re: Work done on / work done by system
When work is done BY the system, then w(work) = some NEG value.
When work is done TO the system, then w = some POS value.
When work is done TO the system, then w = some POS value.
- Fri Jan 19, 2018 8:12 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Difference between Closed and Isolated
- Replies: 10
- Views: 843
Re: Difference between Closed and Isolated
The way that I learned the differences is with examples, so: A Lithium battery is a closed system. At first, I thought it was going to be an isolated because it was sealed off and the internal matter of the battery can't be affected (unless the battery explodes) but I wasn't taking into account the ...
- Fri Jan 19, 2018 7:58 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Adiabatic [ENDORSED]
- Replies: 8
- Views: 407
Re: Adiabatic [ENDORSED]
Adiabatic is used to describe a system, where there is no heat transferred, and when no heat is transferred the total change in internal energy is equal to the work performed (U=w). It would also be a good idea to get familiar with Isobaric and Isometric, which are also other ways systems could be d...
- Fri Jan 19, 2018 7:47 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Calorimeter
- Replies: 10
- Views: 486
Re: Calorimeter
I think (pls don't kill me if I'm wrong, but please correct me if I am) that when we are told that a calorimeter is involved, it will tell us the eternal conditions and tell us what kind of system it is. So a 'bomb calorimeter' is a closed system and a 'coffee calorimeter' is an open system that usu...
- Fri Jan 19, 2018 7:33 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Open systems
- Replies: 6
- Views: 282
Re: Open systems
Usually (I think) we are going to be looking more into closed systems, just because they're all easier to monitor but like Anna said we are still going to look at plain open systems too.
- Fri Jan 19, 2018 7:23 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated system
- Replies: 3
- Views: 217
Re: Isolated system
The definition of an isolated system is "a system where neither mass nor energy can be exchanged with the surroundings". So (internal) heat, can't really be changed because if the heat could be changed then the system couldn't be considered isolated. Usually, these isolated systems are hig...