CHEMISTRY COMMUNITY

Jane_S 2C

Hello!
The equation for work will always be w= -P(delta)V . Your work will end up being positive if the change in V is negative (compressed) which makes sense because then work will be done on the system. It will be the opposite for negative work.

Jane_S 2C

Hello! I often get confused about which equation to use when calculating work. I know isothermal, reversible work requires one equation and other work is another, but how can you remember which equation to use when?

Jane_S 2C

It can be hard to tell what units you need to use when dealing with temperature. My go-to rule is to look at the units we are going to be using in the problem. If you are using the ideal gas constant, you would put temp. in K because there is K in the units of the constant R. In other cases, you can...

Jane_S 2C

It can be confusing at times, but I like to remember it by the (n) in anode being negative, meaning it wants to give its electrons away, and the (t) in cathode looking like a plus sign, ready to accept electrons. It also moves from left to right, which makes sense of anode (negative) going to cathod...

Jane_S 2C

It is important to pay attention to the sign of w when determining if work is being done on the system or surroundings. When work is being done on the system, work is +. You can remember this by thinking that the system is happy (positive) that work is being done on it. When work is being done on th...

Jane_S 2C

Dr. Lavelle, Thank you for being the best chemistry teacher I've ever had. I have had such a hard time learning chemistry, but you make it fun and enjoyable. I find working through problems exciting and rewarding once you get them right. You make class so fun by starting it out DJing and provide use...

Jane_S 2C

Hello! I'm having some trouble with this question.

Calculate the cell potential for the reaction as written at 25.00 °C, given that
[Zn2+]=0.823 M
and [Sn2+]=0.0190 M

Use the standard reduction potentials in the table.

Zn(s)+Sn2+(aq)↽−−⇀ Zn2+(aq)+Sn(s)

Can anyone guide me through the steps?

Jane_S 2C

Hello! I was wondering if anyone has found any redox reaction review videos they find helpful. I haven't taken chem since my sophomore year of high school and could use some good reviews if anyone has them!

Jane_S 2C

When finding Q, we do not add solids or liquids because Q is looking at the concentration of gases only.

Jane_S 2C

K and Kc can be used interchangeably if you are only given the concentrations of reactants and products in the problem.

Jane_S 2C

The standard enthalpy of formation is referring to the amount of heat used/ released in just the formation of products or reactants. The standard enthalpy of the reaction is the amount of heat used/ released in the reaction as a whole.

Jane_S 2C

If we respond to someone's post by clicking the "quotation button" do we still get points for it?

Jane_S 2C

State functions are super important to know because they will tell you have equations to use. For example, in class today Prof. Lavelle showed us an equation that had to have a path function to be able to use it.

Jane_S 2C

Does anyone know how many posts we should be at this week?

Jane_S 2C

I loved Avatar so much I almost wanted to name my dog Zuko! Him or Uncle Iro were my favorite characters.

Jane_S 2C

My all-time favorite TV show is Brooklyn 99. I also really like New GIrl (it is SOO chaotic) and Jane the Virgin. As a kid, I loved anything Disney especially Hannah Montana, probably because we have the same first name and that was the coolest thing ever to me. I have actually never seen New Girl!...

Jane_S 2C

Grey's Anatomy never fails to be super entertaining! Also fun because its very medicine based :)

Jane_S 2C

Maggie Clark wrote:kerckhoff! Im not sure if you consider The Study a coffee place, but that is hands down the best study spot!

The study is so great because you can go into the fish bowl and its noise canceling! Great for studying for long periods of time.

Jane_S 2C

I've tried most of the coffee shops in Westwood, and my favorites (for both coffee and ambiance) have been Profeta and Ministry of Coffee. Both have a good amount of seating and there's usually other people working on assignments too. Warning for Profeta--they don't have any outlets that are availa...

Jane_S 2C

One of my favorite places is Bluestone Lane. Although its expensive, the wifi always works, and the coffee and breakfast burritos are delicious!

Jane_S 2C

I am just a little nervous because I know I got a couple wrong and that makes me feel my grade will suffer a lot as it was only 15 questions and no partial credit! I also think it was pretty nerve-wracking having to think about every question so carefully because every question wrong would lower yo...

Jane_S 2C

Hey!! Honestly feeling pretty good after the midterm. I did every practice problem listed and made sure to review all concepts we covered which really helped. For the next midterm, I'm gonna also go over the achieve problems again.

Jane_S 2C

Anyone have any interesting articles about the newest applications of stem cell research?

Jane_S 2C

Here's another article! http://www.forbes.com/sites/carmendrahl/2017/01/13/chemists-have-braided-molecules-to-make-the-tightest-knot-ever/#7e9b6fa63bf7 Chemists have made the tightest knot! It's a short, fun read. It's pretty "tight." Just read this one!! Super cool and interesting. Makes...

Jane_S 2C

Cp = Cv + R. This is very simple to remember because Cp (constant pressure) is equal to Cv (constant volume) plus the ideal gas constant, R.

Jane_S 2C

A conjugate acid is basically a base that dissociates and gives away a (+ )and therefore becomes an acid anion (-).

Jane_S 2C

I think of it as a backwards scale. Strong acids dissociate fully, which means they release more H+ ions, leading to a lower pH.

Jane_S 2C

K is an umbrella term for all equilibrium constants, where Kc refers to equilibrium in terms of concentration. You can also use Kp to refer to equilibrium in terms of pressure :)

Jane_S 2C

Emily Lam 2H wrote:Does anyone know if we have to memorize strong acids and bases or will it be provided for us?

My TA said we will have to just know most of the acids and bases and if they are strong or weak. However, in practice problems it usually clarifies.

Jane_S 2C

In the equation where it says that pKw = pH + pOH = 14 at 25(degrees c) what does the p mean in the pKw section? And just to clarify the Kw refers to the equilibrium constant when water is involved right? p means 'taking the negative log' of something. For example, pH= p[H3O+] and therefore pH = -l...

Jane_S 2C

Arya Bhalla 1H wrote:Is there a section for Acids and Bases on the 14B Chemistry Community section?

Hello! Yes we are currently on the thread for Acids and Bases on the 14B section. All Acids and Bases material should be here

Jane_S 2C

Hello! While it is recommended to add your discussion section to the username, it is not necessary. It will just make it a lot easier for your TA :)

Jane_S 2C

K and Kc are basically synonymous. K is the overall term to define an equilibrium constant. Kc refers to the equilibrium constant in terms of concentrations, therefore all your units should be in mol/L. Another example is Kp which refers to equilibrium in terms of partial pressures.

Jane_S 2C

Hey! That is so amazing that you're in medical school and on the same path a lot of us students are! I was wondering if you had any advice for someone looking to specialize in ophthalmology. Is it a part of the surgical rotation or something different?

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