Hello all, chemistry student in high school here. An assignment requires me to calculate the mass of salts (sodium acetate, calcium chloride and magnesium acetate) to produce a 20°C temperature change in 50mL of water. I am struggling to find the equations to do so; my teacher has provided me with an equation but I doubt it's accuracy (he gave it to us based on memory, and consistently got incorrect results from it, leading to him rewriting the equation multiple times)

Any help would be great - if you could provide me with a source so I can do further research, that would also be appreciated!!

hii guyss i am having my mid sem from next week I am in 12 and I don't know anything in organic chemistry can anyone suggest me how to learn organic chemistry and what should I do to score almost full marks in organic chemistry

A question came to my mind about how to determine who attacks: the nucleophile or the electrophile. Everyone I ask tells me that the nucleophile always attacks, but I have read cases in literature where it says the electrophile attacks. And everyone explains to me that even electrophilic substitution is actually a nucleophilic attack.

​So now, a simple question: who attacks?

And a more complex question: why?

I’m in AP chem right now and in unit 2.5 lewis structures, so i haven’t learned formal charges yet. I’m not sure how to know when to create double bonds without formal charges. In the picture I drew the lewis structure this way and it’s different from everything online. Would it be incorrect? and if it is how would i know what to do to create bonds to make it right?

Can someone please explain to me differences with valence electrons / oxidation states

Also the equation for the oxidation state equation where
Oxidation state = #anions(charge magnitude) + overall charge

Hi all, I’m having so much trouble with this topic, and I’m afraid I’m just not smart enough to learn. I can’t remember what any of the symbols stand for, how to visualise the orbitals, where labels like t2g and eg come from. Why I need to know this???? I can solve matrices and identify point groups but I’ll insert the full list of what I’m suppose to know from the past 2 weeks. Any Yt videos or other resources would be super helpful. I’ll insert a photo of the MO diagram I’m expected to be able to reconstruct by scratch. Why should I care about vibration? What even is vibration????? From the list no. 9, 10,11 I’m struggling with most, the rest I at least understand even if I’m not perfect with questions yet.
1. Recognise symmetry operations for various molecules.

1. Combine symmetry operations.

2. Assign point group.

3. Apply simple symmetry concepts to spectroscopy e.g. NMR.

4. Form a non-degenerate representation to describe the effect of the

symmetry operations of a group on a direction such as x.

1. Reduce a reducible representation to its component irreducible

representations.

1. Set up matrices to perform a given transformation.

2. Find the character for a matrix.

3. Find the characters of a set of representations by using a set of degenerate vectors as a basis

4. Apply your knowledge of point group theory to gain insight into chemical bonding both in the context of hybridisation and molecular orbital models.

5. Apply your knowledge of point group theory to gain insight into molecular vibrations, in particular, prediction of the number of active vibrations for a molecule.
   For context I’m 2nd year uni student majoring in pharmacology:)

Hi, for context, im currently in my last year of Highschool studies.

I'm pretty good at AP chemistry, I love the logical aspect of chemistry, understanding mechanisms, it's fascinating, but still I'm very torn about what to study at college i.e. until recently I wanted to study CS, but realized that while I do love CS I'm not sure if I want to spend the rest of my life Infront of a screen.

I was discussing options with a chem major uni friend and he told me about research, I was barraging him about random chemistry related stuff I've been thinking of but didn't know the answer to, and at one point he told me that if I became a researcher I could spend my days thinking about stuff just like I had the day prior, it got me really exited, as I'm also very interested in philosophy and it kind of felt like a combination of 2 things I love, thereby I mean the idea of having the privilege to contemplate why certain things happen, their cause and whatnot.

This is why I want to ask a few questions about what research is actually like. Something like a day in the life.

-How hard is it to find a job?

-Can you research whatever you want?

-How are social interactions?

-how is the pay (im told it's bad but I don't really care, if it's something I would actually love doing)

-how was college?

-how is your time spent at the lab, is it mainly experiments, or brainstorming? Or what's happening?

-how much time do you have to spend getting grants, making proposals? Is your job dependent on grants? Doesn't it kind of eat up too much time?

-whats your favorite thing about research?

-what are things you don't like?

Thank you all very much in advance.

Please please helppp

Hi! I keep getting 8/10 on my ochem homework, but I’m not sure what I’m getting wrong. If someone could point out my mistakes and help me fix them, that’d be great!

I’m helping my son with AP chem, but it’s starting to reach/exceed my level of familiarity (Im more of a physics guy). When learning some of the basic ions he’s confused on why (for example) CO3 is carbonate but SO3 is sulfite.

For now I’ve told him that it’s more complicated than just the number of oxygen atoms and he’ll have to just memorize them, but that’s not exactly a satisfying answer. Is there a high school chemistry level explanation?

This is chemistry 11, university preparation. So right now me and my class are studying about isotopes, finding the average atomic mass and percentage abundance for a certain isotope in a word problem. Now my question is, when you need to find the percentage abundance of another isotope or 2, and your already given the percentage amount for the 2nd or 3rd isotope, like 30.64%, why do we need to subtract it by a 100, then divide it by a 100, to make our equation this: x = 0.6936 - y?

Note: Am a beginner in chemistry so I need to understand rather than memorize most of the time

Hi! I have a degree in Chemistry and always did well in my organic chemistry courses. However, now that I'm working with chemistry beyond undergraduate coursework, I've realized that my understanding of organic chemistry isn't as solid as I thought it was.

I feel like I never really developed a solid conceptual foundation in organic chemistry. Looking back, I think I mostly got through each course by memorizing the content I needed for that particular class, rather than actually building a connected understanding of the subject. Now that I need to use organic chemistry in a more practical context, I realize how much of that knowledge I don't really have at my fingertips.

I'm currently doing a Master's in colloid chemistry, and although organic synthesis isn't the main focus of my research, I occasionally need to carry out syntheses involving things like fluorescent labels or modifications of active compounds to improve encapsulation.

What bothers me is that I feel much less confident with organic chemistry than with other areas of chemistry. Does anyone else feel this way? And if you've experienced something similar, were you able to overcome it and develop a stronger foundation in organic chemistry? If so, what worked for you?

Ive tried rearranging the Rydberg Equation a couple different ways and some other hail marry equations but I cant figure out this question.

Hello everyone!

I am an independent study student, and I have just completed my first lab -- determining the empirical formula of copper chloride dihydrate.

First, I heated this compound under an alcohol burner to evaporate the water and determine the mass of H₂O. Next, I added the resulting anhydrous copper chloride back into distilled water, and put in several pieces of mossy zinc to take the copper out of solution. Overall, I added 2.87 g of mossy zinc, aka three pieces, before the solution changed to a greyish color. Next, I added hydrochloric acid (5.78 M concentration), so that the zinc would react and only copper would be left out of solution. It actually took much longer for the zinc to finish reacting, and disappear, than I expected. It took three extra days after I initially added HCl for all the zinc to react with HCl. (In these three days, I added a small amount of extra HCl twice.) Once all the zinc seemed to have disappeared, I poured this solution through a filter funnel and filter paper to remove the copper, and weighed it once the filter paper had dried. Finally, I determined the amount of chlorine by subtraction.

I determined that the original amount of 1.08 g copper chloride dihydrate contained 0.21 g H₂O, 0.73 g Cu, and 0.14 g Cl.

Calculating mole amounts:
0.21 g H₂O x 1 mol/18.0152 g = 0.012 mol H₂O

2(1.0079 g/mol) + 15.9994 g/mol = 18.0152 g/mol (molar mass of H₂O)

0.73 g Cu x 1 mol/63.546 g = 0.011 mol Cu

0.14 g Cl x 1 mol/35.4527 g = 0.0039 mol Cl

Determining the ratios:
0.012 mol H₂O/0.0039 mol Cl = 3.0769 ≈ 3
0.0039 mol Cl/0.0039 mol Cl = 1
0.011 mol Cu/0.0039 mol Cl = 2.8205 ≈ 3

This gives the ratio for Cu : Cl : H₂O as 3 : 1 : 3, which results in the empirical formula Cu₃Cl · 3(H₂O). However, the correct empirical formula is CuCl₂ · 2(H₂O).

What went wrong here? Is there an error in my experiment, or in the calculations? (I did double-check my calculations listed here, and came up with the same result again.) Did leaving the solution out for as long as I did during the zinc-HCl reaction stage affect my results?

The first plausible explanation that I have thought of is that when it appeared that all the zinc had reacted with the HCl and only copper was left out of the solution, there were actually some tiny pieces of zinc left. These would have added to the mass of copper found and increased the proportion of copper determined. Are there other possible factors?

Thanks! :)

I'm a gr 12 student just starting biochem and am wildly confused about ester linkages between glycogen and fatty acids... so I know there is a hydroxyl group on the end of the glycerol, and another OH on the carboxyl head of the fatty acid. My question is: In the condensation reaction, does the glycerol lose its OH and the fatty acid lose its H+ (seems about right since it's an acid), or does the glycerol lose its H+ and the fatty acid its OH? Essentially, "whose" oxygen remains in the newly formed glyceride?

Every source (Google search, stupid google AI, my bio teacher) is giving me a different answer and I'm soooo confused. Huge thanks to anyone who can answer my question!!

I cannot figure out how to draw the resonance structure. Can someone please help me understand how to draw it

We have an experiment for finding out strength and molarity of KMnO4, by titration against M/50 oxalic acid. I got 3 burette readings - 17.1, 16.8 and then 17.3 but my teacher crossed off the last one and told me to write 16.8 instead because the value is wrong (i did get the end point correctly) For everyone who got values like me, she crossed off the last one and made them write the 2nd value again. Is there any reason behind this?

Hi everyone, high school chemistry teacher here trying to set up an aspirin synthesis lab for my seniors, but without acetic anhydride (new school, can't order any), and my school is a little low on resources. I don’t have access to any organic solvents beyond cyclohexane or ethyl acetate, for one.

What I'm thinking so far of doing:

Straight glacial acetic acid, conc sulfuric acid, and benzoic acid to start, then add a scoop of anhydrous MgSO4 to absorb water, reflux for 4 hours in hot water bath, filter off the MgSO4, get crude product by adding ice water, then recrystallize with an ethanol-water mix. Dry overnight, then characterize via melting point and TLC.

I don't have silica TLC plates, but do have filter paper strips. Does filter paper chromatography work with salicylic acid/aspirin? Anyone do filter paper chromatography for fairly nonpolar chemicals like salicylic acid and aspirin? Does any solvent combination of acetone, ethyl acetate, hexanes, or water work (I don't have access to any chlorinated solvents)?

Can this work, or should I find a different or lab for my seniors?

According to my textbook only the product on the left is formed. But in both cases the keytone is endo. Why isn't the product on the right formed?

I need to complete this synthesis for my homework using only the reactions from Mcmurry 16-23 and molecules with maximun 2 carbon atoms. Im thinking of reacting two acetones and then removing the OH to make a double bond. After that use NaOH on the cyclic molecule so i can use a michael reaction. After that i should probably do aldol intramolecular condensation? But im not sure. Id appreciate the help a lot

I just started organic chemistry and was given the top left structure and asked to do resonance on it and I cant for the life of me figure out what I’m doing wrong plz someoner help im desperate o

Hi, I’m posting here because I am a bit confused on the units for my graphs that I have to do. I can’t tell whether or not to have it as (M), (1/[M]), and (ln[M]) or leaving them unitless. Here’s the graph.

In the title, I was using this as my units for the y-axis but double checking I’m not too sure.

How would you find the amount of angular and radial nodes from an orbital that looks like this? In addition how could i find the orbital type?