Search found 32 matches

by Aditya Sundaram 3D
Fri Feb 19, 2021 5:00 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: q and w for an Isolated System
Replies: 11
Views: 36

Re: q and w for an Isolated System

For isolated systems, delta U is always 0 since heat cannot enter or leave and since its isolated, it doesn't lose or gain energy since nothing can go off to the surroundings
by Aditya Sundaram 3D
Fri Feb 19, 2021 4:59 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Internal Energy of a Closed System
Replies: 5
Views: 32

Re: Internal Energy of a Closed System

Closed system just means the amount of substance can't be changed so everything else still applies as per usual.
by Aditya Sundaram 3D
Fri Feb 19, 2021 4:58 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Q Question
Replies: 6
Views: 33

Re: Q Question

C delta T is for calorimeters but when you find q for substances and reactions still use n/m (mol/grams) appropriately.
by Aditya Sundaram 3D
Fri Feb 19, 2021 4:56 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Homework question 4B.13
Replies: 5
Views: 56

Re: Homework question 4B.13

The solution manual is correct on this one. Something that tripped me up is units and converting between J and kJ in the appropriate places.
by Aditya Sundaram 3D
Fri Feb 19, 2021 4:55 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: R gas constant and kPa or Pa
Replies: 9
Views: 21

Re: R gas constant and kPa or Pa

Yup. Definitely try converting the pressure to atm before you start the problem to make everything more familiar and to make everything more standard.
by Aditya Sundaram 3D
Fri Feb 19, 2021 4:54 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Delta U in different systems
Replies: 4
Views: 25

Re: Delta U in different systems

Hi, so I know in an isolated system, delta U = 0, and in a closed system, delta U = w+q; but would we use delta U = w+q for an open system too? Or would there be other factors we have to take in? I believe we still use the same equation but the thing is the values might look different compared to a...
by Aditya Sundaram 3D
Wed Feb 03, 2021 8:38 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Pressure affects only gas reactions?
Replies: 23
Views: 67

Re: Pressure affects only gas reactions?

Massimo_Capozza_1G wrote:It only affects the gas reaction. Solid and liquids aren't really affected because their volume is independent of pressure, I think.


Yeah, these were my thoughts exactly. Concentration is relative and not based on pressure like gasses are.
by Aditya Sundaram 3D
Wed Feb 03, 2021 8:32 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Definition of an Inert Gas
Replies: 15
Views: 53

Re: Definition of an Inert Gas

In Dr. Lavelle's lecture on Le Chatelier's Principle, he talks about how adding an inert gas to a container does not effect the reaction since there is no change in the concentration of reactants, products, and volume. What is the exact definition of an inert gas and why does adding one to a contai...
by Aditya Sundaram 3D
Wed Feb 03, 2021 8:30 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Pressure affects only gas reactions?
Replies: 23
Views: 67

Re: Pressure affects only gas reactions?

Since we use partial pressures for reactions with gasses, changing pressure would definitely impact that. But when we are using concentrations of liquids and solids, not much really changes.
by Aditya Sundaram 3D
Wed Feb 03, 2021 8:29 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: How Does Temperature Affect the Equilibrium Constant?
Replies: 25
Views: 76

Re: How Does Temperature Affect the Equilibrium Constant?

It depends on if the reaction is endothermic or exothermic. If it is endothermic and absorbs heat, then increasing temperature would be like feeding the flames. If it was exothermic and releases heat, decreasing the temperature allows more heat to escape.
by Aditya Sundaram 3D
Wed Feb 03, 2021 8:27 pm
Forum: Phase Changes & Related Calculations
Topic: Vapor vs gas
Replies: 91
Views: 237

Re: Vapor vs gas

Riddhi Mehta 2C wrote:Does vapor usually refer to water or can it refer to any other element as well?


I think for this class we can say it refers to any element.
by Aditya Sundaram 3D
Wed Feb 03, 2021 8:26 pm
Forum: Phase Changes & Related Calculations
Topic: Vapor vs gas
Replies: 91
Views: 237

Re: Vapor vs gas

Neha Gupta 2A wrote:Is there a difference between vapor and gas or are they the same thing?


Nope. These two are the same thing!
by Aditya Sundaram 3D
Wed Feb 03, 2021 8:25 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: sapling #8 week 3/4
Replies: 3
Views: 22

Re: sapling #8 week 3/4

I keep getting stuck on this part of the problem. Can someone help me? 4C(s)+S8(s)⟶4CS2(l) ΔH=+358.8 kJ Calculate the amount of CS2 produced when 401 kJ of heat is absorbed. and then it asks for the mass So in this one, you can tackle it by multiplying the entire equation by the same multiplier tha...
by Aditya Sundaram 3D
Wed Feb 03, 2021 8:22 pm
Forum: Administrative Questions and Class Announcements
Topic: Grading scale
Replies: 29
Views: 214

Re: Grading scale

Eric Ngo 1F wrote:I think the cut off for A- is 92.9% and above is an A :) I think that goes for the rest of the letter grades too. _2.9% being a - and above being an A.


So does that mean the C- to C+ range is 50-80%?
by Aditya Sundaram 3D
Wed Feb 03, 2021 8:04 pm
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Posts in 14B
Replies: 153
Views: 2280

Re: Chemistry Posts in 14B

Kristine_Aramyan_3K wrote:there will be a zoom link provided for the midterm, correct?


Yup, there is a zoom link to join for proctoring based on your discussion section and TA.
by Aditya Sundaram 3D
Wed Feb 03, 2021 8:03 pm
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Posts in 14B
Replies: 153
Views: 2280

Re: Chemistry Posts in 14B

Kristine_Aramyan_3K wrote:exams are mc right?


Yup, the midterms seem to be multiple choice.
by Aditya Sundaram 3D
Wed Jan 27, 2021 9:30 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Difference between Delta H and Delta H Naught [ENDORSED]
Replies: 3
Views: 13357

Re: Difference between Delta H and Delta H Naught [ENDORSED]

Chem_Mod wrote:just deltaH can refer to the enthalpy of anything, unspecified reaction, temperature, pressure, etc

Naught means standard conditions (1 atm 298 K)


So if we are adding H naughts to calculate enthalpy of a reaction, would it remain H naught or become just delta H?
by Aditya Sundaram 3D
Mon Jan 25, 2021 12:13 pm
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Posts in 14B
Replies: 153
Views: 2280

Re: Chemistry Posts in 14B

Sameer Gupta 2F wrote:We need to have made 50 new posts by the end of the quarter.


Is this dependent on TA or is it not?
by Aditya Sundaram 3D
Mon Jan 25, 2021 10:29 am
Forum: Administrative Questions and Class Announcements
Topic: How to find my posts
Replies: 97
Views: 49793

Re: How to find my posts

Aliya Roserie 3I wrote:I also wanted to know.. How do we check to ensure we have posted 5 times each week?


At the right side of your post/reply, it tells you how many posts you have currently so you can just work around that number.
by Aditya Sundaram 3D
Mon Jan 25, 2021 10:28 am
Forum: Administrative Questions and Class Announcements
Topic: How to find my posts
Replies: 97
Views: 49793

Re: How to find my posts

Massimo_Capozza_1G wrote:Does anyone else have a problem when logging into Chemistry Community where you have to re-register each time you sign-in?


Re-register as in your account wasn't created? Or do you mean your account doesn't exist and you have keep creating a new one?
by Aditya Sundaram 3D
Mon Jan 25, 2021 10:26 am
Forum: Administrative Questions and Class Announcements
Topic: How to find my posts
Replies: 97
Views: 49793

Re: How to find my posts

805432537 wrote:A similar question, how do I find my classmates posts. The wides range of dates are a bit confusing.


You can maybe try typing their name in the search bar if you know who specifically you're looking for?
by Aditya Sundaram 3D
Mon Jan 25, 2021 9:47 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Water
Replies: 7
Views: 17

Re: Water

Sameer Gupta 2F wrote:what does it mean for water to be amphiprotic?

Water can both receive and donate protons.
by Aditya Sundaram 3D
Mon Jan 25, 2021 9:25 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE Chart Question
Replies: 15
Views: 82

Re: ICE Chart Question

Does anyone know why when creating ICE charts, and we have a decrease of "-2x" we still have to include the "2" as an exponent when writing out the constant equation? For example, if my product is -2x, and whenever it's time to calculate either K or for X, we would then do produ...
by Aditya Sundaram 3D
Mon Jan 25, 2021 9:13 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Percent Ionization
Replies: 7
Views: 13

Re: Percent Ionization

It is telling us what percent of the acid is separating into hydronium.
by Aditya Sundaram 3D
Thu Jan 21, 2021 8:02 am
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Posts in 14B
Replies: 153
Views: 2280

Re: Chemistry Posts in 14B

Quick question---is everyone planning on memorizing all the strong acids and bases before the midterm? I am planning to, but just want to know if others already know it or are planning to have it all memorized...let me know please! For 14A, I think we had to memorize them anyway but I had Ow so may...
by Aditya Sundaram 3D
Thu Jan 21, 2021 7:58 am
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Posts in 14B
Replies: 153
Views: 2280

Re: Chemistry Posts in 14B

Something that seems optional but should be mandatory is definitely doing the textbook problems and going to the peer learning sessions. It's fairly hard to retain the information just by taking notes from lecture and doing sapling, so going to the learning sessions help a lot. Thanks for letting m...
by Aditya Sundaram 3D
Thu Jan 21, 2021 7:57 am
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Posts in 14B
Replies: 153
Views: 2280

Re: Chemistry Posts in 14B

Eric Ngo 1F wrote:I did too with Ow, and from what I've heard is reading the textbook and doing the practice problems inside it too REALLY help and are important, not just as supplements to Lavelle's recorded lectures.


Good to know! I'll get started on those and hopefully ace the midterm!
by Aditya Sundaram 3D
Fri Jan 15, 2021 5:18 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pressure vs. concentration
Replies: 9
Views: 37

Re: Pressure vs. concentration

I think the way to go about this is considering the units given. But in most instances, I think the questions will be specific as to what they are searching for.
by Aditya Sundaram 3D
Fri Jan 15, 2021 4:45 am
Forum: Student Social/Study Group
Topic: Study Habits
Replies: 96
Views: 320

Re: Study Habits

Studying with a small group or another person immensely helps. It should enhance what you've learned in the past as you either make mistakes and get taught by someone or you catch a mistake and teach them. Either way, it enriches your understanding by a lot and may even help you make less careless e...
by Aditya Sundaram 3D
Fri Jan 15, 2021 4:42 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: H2O as a Gas
Replies: 69
Views: 453

Re: H2O as a Gas

Water would only be on the table if it was in its gaseous state.
by Aditya Sundaram 3D
Fri Jan 15, 2021 4:39 am
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Posts in 14B
Replies: 153
Views: 2280

Re: Chemistry Posts in 14B

I took 14A over the summer and used a different textbook. As a result, I am rusty and at the same time new to the course style, content, etc. What should I know beforehand about succeeding in this course? What may seem optional but really should be mandatory?
by Aditya Sundaram 3D
Tue Jan 05, 2021 5:43 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 1A module #18
Replies: 5
Views: 52

Re: 1A module #18

Equilibrium concentrations are important since they remain constant over time. Initial concentrations change to soon reflect the equilibrium concentrations making it the logical choice to use equilibrium concentrations.

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