An intermediate is a species in the reaction that is created as a product and then consumed in another step. It does not appear in the overall reaction
I'm just praying for a passing grade at this point:) I'm really hoping in person classes resume soon because I don't think I'm learning as well online.
This question says: Consider a process in which an ideal gas is compressed to one-eighth of its original volume at constant temperature. Calculate the entropy change per mole of gas. I know the equation is delta S=nRln(v2/v1) but how do i find n, the number of moles?
For an old Sapling question ( weeks 3/4 #20), the feedback says: First, determine the appropriate expression for the molar heat capacity at constant volume (Cv,m). This is based on the molecular shape of the gas, whether it is an atom, a linear molecule, or a nonlinear molecule. How do I determine t...
The question gives the equation: H^(+)(aq) + Cr2O7^(2−)(aq) + C2H5OH(aq) → Cr^(3+)(aq) + C2H4O(aq) + H2O(l) The answer says that Cr is reduced from 6+ to 3+ and that C is oxidized from 2- to 1- How would I know this? In other words, what steps do I take to figure out which elements are oxidized and ...
I'm working on sapling question where I am given the constant‑pressure molar specific heat, (Cp) and I need to find the constant‑volume molar specific heat of the gas. The hint asks me: How does Cv relate to the constant‑pressure molar specific heat, Cp? Can anyone help me with this?
An old sapling question that I never answered says: Automobile airbags contain solid sodium azide, NaN3, that reacts to produce nitrogen gas when heated, thus inflating the bag. 2NaN3(s)⟶2Na(s)+3N2(g) Calculate the value of work for the system if 32.0 g NaN3 reacts completely at 1.00 atm and 22 ∘ C....
I'm a little confused about the T in the Gibbs equation. Because it's not a delta T, does it mean the change in temperature, the final temperature, or the starting temperature? Or will I just be given one temperature value to use in a problem using this equation?
The question asks which system does more work: an irreversible reaction or a reversible reaction. The textbook's answer goes through the steps of calculating the amount of work done by the irreversible expansion. But, the textbook also said that "the greatest work done is for a process that tak...
Can someone walk me through the steps to solve a question like this? I have a general idea but I must be doing something wrong because I can't get the right answer.
Is there a relationship between the strength of the bonds in a reaction and whether or not that reaction is endothermic or exothermic? If so what is it?
I would also agree with lots of practice! I know Lavelle mentioned this quarter was going to consist of more problem solving than last quarter so I think it would be especially helpful to get more practice in as a study tool.
The value of Kw for water at body temperature (37 °C) is 2.1×10−14. (a) What is the molar concentration of H3O+ ions at 37 °C? (b) What is the molar concentration of OH− in neutral water at 37 °C?
Are you supposed to assume [H30+] and [OH-] are equal and divide Kw by two?
A reaction mixture that consisted of 0.400 mol H2 and 1.60 mol I2 was introduced into a flask of volume 3.00 L and heated. At equilibrium, 60.0% of the hydrogen gas had reacted. What is the equilibrium constant K for the reaction H2(g) + I2(g) ⇌ 2HI(g) at this temperature? I'm confused on how to go ...
I'm trying to answer this question, but I'm stuck. I know you line them up but do I add all the values or subtract to find a difference or something else? The example in the book seems to confuse me more so if anyone can let me know the steps to get through a problem like this that would be great:)
I'm working through this module and I'm not sure if I'm doing this right. #14 says: The two air pollutants SO2 and NO2 can react in the atmosphere as follows: SO2 (g) + NO2 (g) ⇌ SO3 (g) + NO (g) Predict the effect of the following changes to the amount of NO when the reaction above has come to equi...
17. You are studying the following unbalanced reaction at high temperatures: NH3 (g) ⇌ N2 (g) + H2 (g) In one of your experiments at 500K the measured partial pressures are: NH3 0.887 bar H2 0.168 bar N2 0.0561 bar a) Determine the equilibrium constant for this reaction at 500 K. I don't really unde...
Why are equilibrium constants useful? I answered: One number that gives us information about the relative production rates of reactant and product. But that was wrong, so I'm wondering what the correct answer is. Thanks!!
Also I would say make sure you're getting every point you can. Do all of the chemistry community points and homework points, because these are huge grade boosters and can really determine a passing grade from a failing grade in the end :)
Question 9C.5 says: Which of the following ligands can be polydentate? If the ligand can be polydentate, give the maximum number of places on the ligand that can bind simultaneously to a single metal center: (a) HN(CH2 CH2 NH2)2 ; (b) CO3 2 − ; (c) H2O; (d) oxalate. I'm not really sure what a polyde...
Do lone pairs come into play in hybridization? If a molecule has a lone pair, I know it affects the shape so how does that correlate to the hybridization?
Okay, so 2.F.1 says: State the relative orientations of each of the following hybrid orbitals: (a) sp3 ; (b) sp; (c) sp3d2. So if there are multiple shapes that have sp3 or sp2, could there be two answers for part a of this question?
the textbook's answer says, "the smaller the pKb of a base, the stronger the base. pKb (morphine)= 5.79. pKb (BrO-)= pKw-pKa=14-8.69=5.31." This reasoning is confusing me because I don't know how they calculated pKb and pKa. Can anyone explain how they got those numbers?
the textbook's answer says, "the smaller the pKb of a base, the stronger the base. pKb (morphine)= 5.79. pKb (BrO-)= pKw-pKa=14-8.69=5.31." This reasoning is confusing me because I don't know how they calculated pKb and pKa. Can anyone explain how they got those numbers?
In today's review session with Lavelle, he went over several problems from the midterm and showed the answers, so if you weren't able to get your answers from your TA, you can watch the recording of this review session, which Lavelle sent a link to in an email today.
I'm having a hard time understanding some aspects of dipoles as a whole. One thing I'm stuck on is an old sapling question. How do you know this is Dipole-Dipole? Thanks
I'm reviewing topics in preparation for the midterm, and I know I'm iffy on determining which bonds are more ionic vs more covalent in character. Any tips on how to figure this out? For example, Sapling question 10 from last week lists: Br-F, F-F, Cl-F, Ca-F, K-F and asks you to put them in order fr...
Okay, I've gotten to the last part of this question where there is a table with bond lengths. I'm not sure what ample & overwhelming bond character mean.
The next part of this question asks: "Which of the Lewis structures would be expected to contribute the least to the overall structure of the carbamate ion?" How would I figure out the answer to this?
Hi! I've been trying to go back through the lectures to find the formula for formal charge and I can't find it. Based off this post, I think the formula is: formal charge= valence electrons-( (bonds/2) + lone pairs). Is this correct?
Hi! I was also struggling to really understand electron configuration, and I found that this link to a Khan Academy video helped a lot: https://www.youtube.com/watch?v=NIwcDnFjj98
Hi! I had a similar question: Calculate the wavelength, in nanometers, of the spectral line produced when an electron in a hydrogen atom undergoes the transition from the energy level n=6 to the level n=1. My answer is 9.394*10^-8 and I can't figure out why my answer is wrong.
Okay for this question I got the answers: from 37.61nm to 12370nm and it is telling me that 37.61nm is wrong, but I don't understand why. Any help would be great!
I've been finding that the textbook questions are harder than the Sapling questions/ other practice problems Lavelle show us. Is anyone else feeling this?
Lavelle says in the syllabus that doing the textbook problems, doing the Sapling homework, and completing all the modules on his website should prepare you well for the midterm.
Does anyone have any good study tips for this midterm? I've been going back over the book questions for review but I'm not sure what else I should be studying.
Hey, I think I need to start attending step up sessions, do I have to sign up for them? Or do I just go to the zoom link during that time? From what I've heard, you do practice problems... is there a packet I would need to have ready/print beforehand?
I needed a refresher course on molarity as well, and I found that the video under Audio-Visual Focus-Topics titled "Molarity and Dilution of a Solution" on Lavelle's website to be super helpful.
I ordered my textbook to be picked up at the UCLA store and got a confirmation that it shipped, but that was almost a week ago. Does anyone know how long it takes for it to be delivered to the UCLA store once it ships?
I think I understand the steps in this question, but how do you know if the equation is balanced? Are we supposed to assume it is balanced, and if not how would I go about balancing it?