CHEMISTRY COMMUNITY

Shana Patel 1C

Just finished Bridgerton.

Shana Patel 1C

You need a 50% to pass with a C-, which is equal to 200/400 points.

Shana Patel 1C

I think if you have 50 points you should be fine. This is for those who missed a couple of points during the quarter.

Shana Patel 1C

You can memorize or calculate it.
Rate = k a to a power. So Zero is m/s. One is 1/s and second is 1/sm.

Shana Patel 1C

To get the overall order of the reactions, you need to add the orders together.

Shana Patel 1C

The slow step should have the highest activation energy.
You would also find the products of the slow step in the final reaction.

Shana Patel 1C

Thank you so much for all the help!!

Shana Patel 1C

The reaction is not complete until that slow step is fulfilled. Therefore the slow step determines the rate of the whole reaction.

Shana Patel 1C

Personally, I enjoyed Chemical equilibrium.

Shana Patel 1C

J/mol or kJ/mol

Shana Patel 1C

It is possible for there to be more than 3 reactant, however, I doubt Dr. Lavelle would address these instances in class.

Shana Patel 1C

Yes, unless the question says that phases are optional.
Usually you should just include the states of matter.

Shana Patel 1C

Example of zero reaction - Photochemical reaction between hydrogen and chlorine.
Example of first reaction - the hydrolysis of aspirin.
Example of second reaction - basic hydrolysis of an ester.

Shana Patel 1C

In first and zero order reactions, the slope is -k.
In second order reactions, the slope is +k

Shana Patel 1C

Most of the time they ask about half-life in relation to the order reactions. For example, they can just give you a description for you to calculate half-life on its own, or ask what order a reaction is based on its half-life.

Shana Patel 1C

What do you do when a chemist dies?
You Barium.

Shana Patel 1C

You dont need to memorize any of them but with practice you kind of start to remember them automatically. It isnt difficult to understand how it works, making it easier to memorize.

Shana Patel 1C

The oxidizing agent is being reduced and the reducing agent is being oxidized. To remember, its the opposite.

Shana Patel 1C

A salt bridge is a laboratory device used to connect the oxidation and reduction half-cells of a galvanic cell, a type of electrochemical cell. It maintains electrical neutrality within the internal circuit.

Shana Patel 1C

The anode is always on the left and the cathode is always on the right.

Shana Patel 1C

E cell naught is the cell potential at standard conditions while E cell can be at any random conditions.
The equation that shows the realtionship between the two is:
E cell = E cell naught - (RT/nF)lnQ

Shana Patel 1C

Do you have 11 protons?
Cause you sodium fine!!

Shana Patel 1C

Thank you so much for sharing this, it will help me a lot. I always confuse the two.

Shana Patel 1C

Le Chatelier's Principle only applies to gases. However this does not affect the solid and pure liquid systems since their active masses are always taken as unity.

Shana Patel 1C

Congratulations to everyone!! We only have a few more weeks left.

Shana Patel 1C

You need to get atleast 50% in the class to get a C- and pass the class. If not, then you will need to repeat the class. That is 200/400 points

Shana Patel 1C

Why is the pH of Youtube so stable?
Because it constantly buffers.

Shana Patel 1C

I am not sure if I should take chem14BL and chem14C or only chem14BL. I do not know if the workload will be too much.

Shana Patel 1C

In order to get the right answer with the right units, convert kPa to atm. It makes it easier.

Shana Patel 1C

ΔG⁰ refers to free energy in standard states, whereas ΔG refers to free energy in any state.

Shana Patel 1C

I think you are panicking when you study because of your midterm grade.You need to relax when doing this type of work. Use your tectbook and go througheach topic at your own pace, and answer the questions that come after. If you get stuck on anything, use chemistry community. The UA sessions help a ...

Shana Patel 1C

These tips are so helpful! I think it is important to practice these techniques to improve our learning methods.

Shana Patel 1C

The units usually depend on the problem being solved, and the other units given in the question. The units are usually given on the exam sheet, so we just need to know how to apply everything.

Shana Patel 1C

I thought it was the same thing, and I am assumung that we do not need to know the difference between the two for the class. However I found that vapour phase consists of a phase with two different substances at room temperature, whereas a gas phase consists of a single substance at a defined thermo...

Shana Patel 1C

I think the textbook helps a lot if you study each topic and do the recommended questions that come with it. Doing the homework Sapling questions also work well to make you understand the syllabus better. Lavelle's lectures are extremely helpful, therefore I would just recommend making short notes f...

Shana Patel 1C

A neutron walks into a bar. He asks the bartender, "How much for a beer?"
Bartender gives a smile and says, "for you, no charge!"

Shana Patel 1C

Are you full of beryllium, gold, and titanium?
-> Because you are Be-Au-Ti-full

Shana Patel 1C

A phase change is when the state of matter of an substance changes between solid, liquid, or gas.

Shana Patel 1C

Exothermic reactions will always be negative because the total energy of the products is less than that of the reactants which is why energy gets released.

Shana Patel 1C

The calculations involve delta T, you do not convert the temperature units as Kelvin and Celsius have the same increments between each unit of measure.

Shana Patel 1C

What happens to K when you reverse a reaction?

Shana Patel 1C

X stands for the C row - the change in equilibrium. This figure will be multiplied by the stoichiometric coefficient. This is all found in the ICE table.

Shana Patel 1C

Taking the -log[H+] will give you the pH. After finding the pH, subtract the number from 14 to give you pOH.
pH + pOH = 14

Shana Patel 1C

What do you call an acid with an attitude?
-> A-mean-oh acid

Shana Patel 1C

Thank you so much!! It really helped.

Shana Patel 1C

I think doing questions from the textbook will allow you to find the exact topic you are not comfortable with. After finding this out, it will be easier to study because you will know the topics you have to work on. Completing the sapling homework will also help a lot. If you have any questions, ask...

Shana Patel 1C

A sample of an ideal gas in a cylinder of volume 3.04 L at 298 K and 2.62 atm expands to 8.40 L by two different pathways. Path A is an isothermal, reversible expansion. Path B has two steps. In the first step, the gas is cooled at constant volume to 1.36 atm. In the second step, the gas is heated a...

Shana Patel 1C

Zoe FC 1C wrote:Ok, thank you! And we just have to memorize the strong acids and bases right? I took 14A over the summer so I'm a little rusty on acids and bases.

Yeah! For Chem14a our professor said we should memorize the strong acids and strong bases because there are only a few compared to the weak ones.

Shana Patel 1C

This only applies to gases because they can be compressed. However, liquids and solids cannot be compressed therefore could not work.

Shana Patel 1C

Yes! Ka and Kb is essentially the same when it comes to calculations, but different only for naming purposes.

Shana Patel 1C

You talk funny when you breathe helium!
He He He

Shana Patel 1C

A 0.305 mol sample of Xe(g), initially at 298 K and 1.00 atm, is held at constant pressure while enough heat is applied to raise the temperature of the gas by 19.3 K. Calculate the amount of heat q required to bring about this temperature change, and find the corresponding total change in the intern...

Shana Patel 1C

What did one atom say to the other on their first date?
--> I think we bonded.

Shana Patel 1C

KTran 1I wrote:Are there a lot of topics in the book that are not covered during lecture that show up on tests?

I would advise just checking which topics are repetitive in the textbook and in the syllabus. The textbook gives a lot of detailed questions, so I usually just go through all the topics.

Shana Patel 1C

On Chemistry Community you have to log in using your UID, then find CHEM 14B. All the topics are posted there, including questions related to the topic. You can post a new question(like you have done), or repluy to other peoples questions by clicking the post reply button at the bottom of the page.

Shana Patel 1C

Why is it that a change in pressure causes an increase in concentration Changing the pressure, changes the conditions of the reaction and therefore the position of equilibrium shifts. When this happens, the shift is toward the side with fewer moles of molecules. Increasing the pressure of a gas is e...

Shana Patel 1C

We usually use Kelvin when calculating temperature. There is a formula to change Degrees to Kelvin; T(K)=T(C) + 273.15

Shana Patel 1C

Why do chemists learn about ammonia first?
--> Its pretty basic stuff

Shana Patel 1C

I think it is right to say that an alkaline solution/compound is the same as a basic solution/compound. However, an ALKALI is a base (that dissolves in water).
Not all bases are alkali but all alkali is base.

Shana Patel 1C

America Alvarado wrote:
America Alvarado wrote:How do we calculate the [H+] and [OH-] if we are only given the pH. For example, pH of 8.85 at 25 °C.

I think I figured it out, would we do 10^(-8.85) to find [H+]?

Yeah! Then calculate pOH using the formula pH+pOH=14, followed by 10^(-pOH) to calculate [OH-].

Shana Patel 1C

pH of 8.85
[H+] = 10^(-8.85)
pOH = 14 - 8.85 = 5.15
[OH-] = 10^(-5.15)

Shana Patel 1C

I think he posted something about the exact details of what wass going to be on the final. Since acid-base has not shown up anywhere else, I assume there would be a lot of it on the final. Study hard!

Shana Patel 1C

Did you know that oxygen went on a second date with potassium?
How'd it go?
It went OK2

Shana Patel 1C

The acid dissociation constant is the equilibrium constant of the dissociation reaction of an acid and is denoted by Ka. This equilibrium constant is a quantitative measure of the strength of an acid in a solution and is expressed in units of mol/L.

Shana Patel 1C

Correct me if I am wrong but octahedral molecules have six atoms bonded to the central atom and no lone electron pairs, making the steric number equal to six. The formation of the surrounding atoms gives octahedral molecules their overall shape of eight connected triangles. Other molecules might not...

Shana Patel 1C

The conjugate base of a Bronsted-Lowry acid is the species formed after an acid donates a proton.
The conjugate acid of a Bronsted-Lowry base is the species formed after a base accepts a proton.

Shana Patel 1C

I watch these videos all the time! They are extremely helpful. Especially if you know the exact topic you want to review.

Shana Patel 1C

The following are the conditions for hybridization to occur: a) The orbitals undergoing hybridization generally belong to the valence of the atom. b) The orbitals taking part in hybridization must have only a small difference of enthalpies. c)It can take place between completely filled, half-filled,...

Shana Patel 1C

Study each topic, then go through the questions we got on sapling as homework. Follow this up by reviewing your problem-solving skills from the textbook. The questions assigned to us are very helpful and make you understand the topics better.

Shana Patel 1C

I usually go on hikes or runs, but the weather is getting colder, so I started some yoga.

Shana Patel 1C

To know if a molecule is polar or nonpolar, you can look at its arrangement. Draw out its arrangement and draw arrows - arrows point toward the more electronegative element. If it has a symmetrical arrangement and has arrows that have equal length, the molecule is nonpolar. If it has an asymmetrical...

Shana Patel 1C

I usually draw it out to make sure I don’t miss any bonds. Each single bond consists of only one sigma bond and a double bond consists of one sigma bond and one pi bond. Just count them out from the structural diagram.

Shana Patel 1C

Can shape alone tell if a molecule is polar or nonpolar?

Shana Patel 1C

There are different versions of the textbook and some of them have the wrong answer keys for a few of the questions.
I have seen many posts on chemistry community talking about this. So i would recommend just double checking your answers and you should be fine.

Shana Patel 1C

Is there a way to remember the bond angles for compounds/molecules or should we just memorize them?

Shana Patel 1C

I hope the grades are released before Thanksgiving, so we can enjoy the holidays without thinking about it.

Shana Patel 1C

All the good chemistry jokes ARGON?
I don't ZINC so!

Shana Patel 1C

I think everyone is worried because we have only done one midterm and I don’t think everyone has done as well as they expected, however we still have time to fix our grades. Just work hard now to get our second midterm grades higher.

Shana Patel 1C

Hydrogen bonds require a large electronegative difference which is not found when bonding with S. The electronegative difference between hydrogen and nitrogen and oxygen and fluorine is high therefore forms hydrogen bonds.

Shana Patel 1C

My TA said it was the same formatting as the first midterm. We will be proctored again and the midterm will be multiple choice questions.

Shana Patel 1C

Chemistry teacher - What is the chemical formula of water?
Student - HIJKLMNO
Chemistry teacher - What are you talking about??
Student - Yesterday you said it was H to O

Shana Patel 1C

Other than the APP program and the office hours, is there any other way to get, one on one help?

Shana Patel 1C

how do we count the number of electrons each element has?
The number of electrons is equal to the atomic number. This is the number of protons in an atom.

Shana Patel 1C

In one of the lectures he was explaining how the orbitals worked, and he mentioned that we will not be learning details about the f orbitals.

Shana Patel 1C

My TA, Andrew Salmon, talked about the orbitals in discussion this week. It's helpful to draw out the chart making columns of 1-7s, then 2-7p, then 3-7d, and finally 4-7f. From there, lightly draw diagonal arrows over 1s, then 2s, then 2p and 3s, then 3p and 4s, then 3d and 4p and 5s, keep repeatin...

Shana Patel 1C

Right before the final, I feel like it is important to take a few minutes to relax and not stress about anything. You need a clear mind before focusing. Also, I would recommend reading ahead of time, before finals week, because there is so much to do and it will be overwhelming to finish everything ...

Shana Patel 1C

Two men walk into a bar. One man orders H2O. The other says, "I'll have H2O too!"
The second man dies.

Shana Patel 1C

Becca Nelson 1J wrote:What is the 2nd best public university's favorite element?

Berkelium!

Why did I laugh so hard at this??

Shana Patel 1C

Thank you for clarifying for me.

Shana Patel 1C

When giving us credit for participating in the chemistry community, will they take our total number of posts and divide by 5 to see how many weeks they are for, or are they actually cross-referencing with the time you post it. If they are referencing, is it possible to check how many points you get ...

Shana Patel 1C

What do you do with a sick chemist?
.
.
If you can't helium, and you can't curium, you might as well barium.

Shana Patel 1C

The E.coli bacterium is about 2.3 μm long. Suppose you want to study it using photons of that wavelength or electrons having that de Broglie wavelength. What is the energy Ephoton of the photon? 8.64×10^−20J What is the energy Eelectron of the electron? I understand how to do the first part of this ...

Shana Patel 1C

You do not need to buy a webcam anymore, a phone is good enough. Log on to your zoom call through your phone, and access the midterm from your laptop and you should be fine.

Shana Patel 1C

What did one charged atom say to the other?
.
.
.
I got my ION you!

Shana Patel 1C

Are there different marks allocated to different questions? For example, if there was more work to do in one question and another was an easier question, are they both rewarded the same marks?

Shana Patel 1C

I think we are allowed scratch paper as long as the TA can see it when you write. The paper should be visible on the zoom call.

Shana Patel 1C

I think they mentioned that they will not try to. trick us in terms of sig figs on the midterm. None the less, you should not round up until the very last answer (final answer).

Shana Patel 1C

There are Van der Waal forces are the attraction of intermolecular forces between molecules. Therefore small interactions can occur but it depends on the situation because molecules need a certain amount of energy to bond.

Shana Patel 1C

505106414 wrote:Is an ionic or a covalent bond typically stronger?

Ionic bonds are stronger than covalent bonds because they involve the trtansfer. of electrons rather than a sharing of electrons.

Shana Patel 1C

It depends on the situation. Covalent bonds are formed from the sharing of electrons between nuclei and, ionic bonds are formed from mutual attractions between oppositely charged ions. Ionic bonds tend to be stronger than covalent bonds. In high school, I was taught that ionic bonds are the stronges...

Search found 111 matches