CHEMISTRY COMMUNITY

Jess Max 2F

I am just wondering what molecularity is, vs bimolecular, and what are the associated steps/rate laws with each molecularity?
Thanks!

Jess Max 2F

I am not quite understanding the steps and procedures for how to solve #13. i am confused by what to identify first and how to know what order to solve in. Can anyone explain?
Thanks!

Jess Max 2F

Hi! I'll go through the problem. So according to the rate law you'll see that the reaction in A is first order because it has no exponent above it in the rate law. B is second order because there is a 2 exponent. If the concentration of a first-order reactant is halved, the reaction rate changes by ...

Jess Max 2F

Hi, to start by breaking down part A: The reduction will occur at the electrode with a higher concentration of the substance, which is what concentration cells are designed to do so that reduction will lower the cation concentration in the cathode so the entire concentration will move closer to equi...

Jess Max 2F

Natalie Bender wrote:We know 0.075M goes in the numerator because when you write out the full balanced equation you get:
H2 (left) + 2H+ (right) --> 2H+ (left) + H2 (right)

Can you please explain how you even know how to write out the half-reactions and full equations? i don't quite understand it. Thanks!

Jess Max 2F

I am still confused about how to approach this, mainly because I'm unsure how even to look at what's given and interpret it. Can anyone please tell me what the single lines are, I think I know the double line represents the film between the anode and cathode sides of the reaction, but in 6N.3 part a...

Jess Max 2F

Hi, I just wanted to clarify the correct procedure for finding the reduction potentials of half-reactions to use together to find the equilibrium constant. Do you find the reduction potential of the oxidation half-reaction and flip the sign? or do you stick with the exact number and sign and then su...

Jess Max 2F

To first identify the anode half rxn that oxidizes throughout the rxn, you're correct that Mg is oxidizing because its oxidation number increases, thus it loses electrons. using the table we find that the Enaught value is -2.38. The cathode half rxn is was reduces throughout the equation, and we see...

Jess Max 2F

Hi! to go through every variable: E naught would be the standard cell potential of the half-rxn, n is the number (mols) of electrons transferred during the half-rxn, and Q is the reaction quotient (Q is what I was confused about how to calculate). we know that because its a standard hydrogen electro...

Jess Max 2F

Hi! So when balancing a reaction in basic solution, I know you add H2O to balance the O, then H+ to balance the H, then OH- to both sides to balance the H+ ? (correct me if I'm wrong). So I am wondering, if after these steps, you can combine all the OH- 's and H+ 's to make H2O's? Or do they stay se...

Jess Max 2F

Galvanic cells are used when the species are different and concentration cells are used when the species are the same (but concentration of the species on both sides is changed). Just make sure to remember that E naught of concentration cells is always zero. Hope this helps! Thank you for the expla...

Jess Max 2F

So I know E(naught) is an intensive property, doesn't depend on how many times it's performed, etc, but is regular E the same, also intensive? And what is the exact difference between the two, when do you use each one?
Thanks!

Jess Max 2F

The anode releases electrons and is oxidized, and the cathode gains them, and is reduced!

Jess Max 2F

I remember that the agent does the opposite of what is done to it- so if the agent is oxidizing, that means it itself is being reduced so the electrons taken from another compound are added to the oxidizing agent. If the agent is reducing, then it is adding electrons to a compound, so those electron...

Jess Max 2F

How would you balance the solution if it were in an acidic solution?

Jess Max 2F

Hi all,
i’m just wondering why this equation: deltaH= deltaU + PdeltaV is not on the constants and equations sheet. is this directly derived from deltaU = w + q, where w = PdeltaV, deltaH = q? in what circumstances can we assume it is ok to use this equation?

Jess Max 2F

Hi, I am having trouble with part c of this problem. Calculating work was 28 J, and part b answer is positive, but the textbook answer for part c said the change in internal energy (U) of the system was 8 J. How do we get this answer? Knowing the change in U = q + w, I tried to calculate q but i don...

Jess Max 2F

Hi, I saw this on the equation sheet (the image should be below) : and was wondering if the qrev/T one is specifically for S(surroundings), and that just wasn't specified on the sheet. And then the other delta S equation is used for S (system), right? So I wanted to confirm that we would never set t...

Jess Max 2F

Hey guys, I'm trying to find a tutor for chemistry and was wondering if anyone has recommendations for tutors or companies that could help. I'm looking for someone that specifically knows the UCLA chemistry 14B series content if possible. Let me know! Thanks.

Thanks :)

Jess Max 2F

Hi guys! Does anyone have any suggestions or know where I can find a tutor for this class (14B)? I'm hoping to do a session every week and would love to find a tutor who specifically knows the 14 series here at UCLA. Let me know!
Thanks :)

Jess Max 2F

Is anyone able to break down the steps necessary to create this equation? I am not sure what equations to use to find the number values to plug into the final
" 18297.1111+ 54.8 * 4.184(Tf - 0.0)= - 445 * 4.184(Tf - 45) " that Emmett shared.
Thanks,
Jess

Jess Max 2F

And does the standard reaction enthalpy of each compound change depending on whether it is a reactant or product, or does its value stay the same and only change depending on how many mols of a substance there is in the equation?

Jess Max 2F

hi! I'm not sure about your first question, but for the second question, I know that the reaction is formation when the reactants are both pure and the elements are in their standard states. Also, there must be a single product with no coefficients. The reaction is bond energy only when the reactio...

Jess Max 2F

So just to clarify, Na+ and NO3- are classified as spectator ions in this equation? Because they are not part of non-aqueous compounds, and their product is aqueous, they are not included?
Thanks for the explanation!

Jess Max 2F

When you are given the Ka for a weak acid and told to use its conjugate base in a reaction and calculate the pH for that reaction, you will need to convert the Ka given into the Kb for the conjugate base. To do this divide Kw (1.0 x 10^-14) by the Ka value. Then set up the equation the way you woul...

Jess Max 2F

When can we decide to disregard x is the denominator of an equilibrium equation from an ICE table? ex) Ka= (x^2)/(0.137 - x)
When can we simply take x out of the denominator so the quadratic equation isn't necessary? Does it have to do with the value of Ka?
Thanks!

Jess Max 2F

So, any lone element even with a charge is neutral, neither acid nor base? Because it is not a compound?
Also, is it always true that a compound with a positive charge is an acid and can donate protons, and a compound with a negative charge is a base that accepts protons?

Jess Max 2F

You never include solids and liquids! They each equal 1 in the equilibrium equation. Just (aq) and (g) I believe.

Jess Max 2F

What are the exact criteria for distinguishing between heterogenous and homogenous? Thanks

Jess Max 2F

In an equation where you are given 1) the volume of the container, 2) the concentration of the sole reactant before the reaction, and 3) the concentration of one of two products at equilibrium, how do you calculate each of the x's in the ICE table and still find Kc too? It seems like there are too m...

Jess Max 2F

P stands for pressure, V stands for volume, n is the number of moles of the ideal gas, R is the ideal gas constant (which may change depending on your units of pressure and volume), and T is the temperature (in K). --> What would the different values of R be, and depending on which different units ...

Jess Max 2F

Yes you can use the ICE box for both Kp and Kc the only difference is if you're calculating partial pressures of gasses (P) or the concentration of substances (C).

CHEMISTRY COMMUNITY

Search found 32 matches

molecularity vs bimolecularity

Achieve week 10 #13

Re: Achieve W8-10 #5

Re: Focus 6 Exercise 6.53

Re: Textbook 6N.3a

Re: Textbook question 6N.3a

flipping sign of reduction potential for oxidation half-rxn

Re: Week 7&8 Achieve HW #15

Re: Week 7&8 Achieve HW #17

adding H+ and OH- to make H2O in redox rxn?

Re: Galvanic Cells VS Concentration Cells

E(naught) intensive vs E

Re: Electron transfer

Re: Oxidation and Reducing Agents

Re: How to Balance Redox Reactions

deltaH = deltaU + PdeltaV not on equation sheet?

Textbook Problem 4A.3

change in S surroundings

Chemistry Tutoring

Finding A Chemistry Tutor

Re: Achieve Question 10 Week 3 and 4

Re: Standard reaction enthalpies

Re: How can you tell if rxn is combustion, formation, or bond energy?

Re: spectator ions in K equation

Re: Achieve question 7 and 8

when x is small enough to disregard

Re: Example 6D.4

Re: What is included in equilibrium equation

Re: Homogenous vs Heterogenous equilibria

How to Solve for Kc when given only some concentrations of R and P's

Re: PV=nRT

Re: Using ICE