CHEMISTRY COMMUNITY

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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...

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Does anyone know the exact number of pts out of 500pts one needs to be able to get a B-?

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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 ...

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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?

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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 -...

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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.

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Same applies if say a question was to mention something happening in space as well.

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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.

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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 ...

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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.

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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 ...

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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...

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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...

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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.

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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...

CHEMISTRY COMMUNITY

Search found 15 matches

Re: Minimum for a B-?

Minimum for a B-?

Test Grading

Balancing

Re: Balancing

Re: Addition of H3O+ or OH-

Re: Internal Energy in a Vacuum [ENDORSED]

Re: Reversible systems

Re: Isobaric [ENDORSED]

Re: Work done on / work done by system

Re: Difference between Closed and Isolated

Re: Adiabatic [ENDORSED]

Re: Calorimeter

Re: Open systems

Re: Isolated system