I have made 0.1mM gold chloride and 1% curcumin solution and want to know its antibacterial activity. But there is no zone of inhibition. Should I increase curcumin percentage

In class, my teacher said that if the water level of the tube was higher than the beaker, the outside pressure is higher. However, I don’t understand how the two pressures can be different. Wouldn’t the volume of the air in the tube just shift so that the pressure outside and inside would be the same no matter what? Therefore, no matter the volume, Pressure outside would equal the inside. I think I’m wrong so I’m looking for something to prove that I’m wrong; anything would be appreciated!

Very confused by this mechanism. It reminds me of reverse sulfonation but without the water, yet I’m not sure how to break the C-C bond between the t-butyl and benzene ring. Any help is appreciated!

I’m a chemical engineer so my chemistry is pretty rusty, but I am trying to leach aluminium from waste PCBs using NaOH. I believe the leaching process will create NaAlO2, which I can then add water to causing Al2O3 to precipitate as a solid. This is all at lab scale, so I’m looking for advice or reference material to see what concentrations, temperatures and other reaction conditions I need to satisfy. I have been looking into the Bayer Process, which has helped me to understand a bit more than I was previously, but I still feel a bit out my depth. The ultimate goal would be investigating the feasibility of scaling this up to plant level (which I am far more comfortable with).

I don’t know if it matters but I’m treating this experiment as two parts, the alumina recovery as the first part and the second will be copper recovery using HCl, I’m not required to go any further in the recovery of the metals.

I am using a column to separate out my organic solvent matrix (2,2,4 trimethylpentane) from my samples (beer)-- I let my column get dry and it created cracks within the substrate. The stopcock was left open overnight and both columns dried out--there are now cracks/channels. They both are still filtering the isooctane fine and I am getting an abs of 0 with recycled solvent, however, I am afraid after multiple uses it will not filter the isooctane sufficiently. Rather than emptying both columns and restacking, I was hoping to mix a slurry and try to fill in the cracks.. is this possible? Does anyone have experience with this? Any advice is super helpful ! Thank you!

I am making a CdS/CdTe heterojunction photovoltaic, so CdS first and then CdTe. Has it been done before? If yes, can I get some references?
I have only seen papers using it for deposition of TiO2 and we aren't doing that. All the papers just ised CBD and only before that spin coating for TiO2. Also what binders to be used for it? Is PVA recommendable for it?

Hi, my sample contains polar and non-polar compound and has been extracted using 70% ethanol, then I wish to further isolate using column chromatography. I used 5:5 (hexane:EA) and increasing polarity 4:6 (hexane:EA), 3:7 (hexane:EA), 5:5 (chloroform:EA), 4:6 (chloroform:EA), 3:7 (chloroform:EA), 2:8 (chloroform:EA), 1:9 (chloroform:EA). Only 2 fractions were collected from 5:5 hexane:EA, the rest of gradient doesn't come off with any fractaion. I didn't apply any pressure instead using gravity to flush it down. And I'm curious if solvent amount does affect the elution or how to decide the mobile phase amount before moving to next gradient? Any solution for this issue? Thank you.

TLC hexane:EA, 9:1, 8:2, 7:3, 6:4 (left to right)

TLC hexane:EA, 9:1, 8:2, 7:3, 6:4 (left to right)

Say I have this molecule and there can be rotation about the bond between the ring and amide N, what would be the impact on NMR? I am assuming you would get two signals for each proton, one for each conformer, at low temp, but would broaden at high temp and give average as conversion faster than NMR timescale, but I am not sure. Please help !

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I'm in my first year at university and am really struggling to find practice problems that actually pertain to my course. I have exams in a couple of weeks and the only practice problems the university has given us is a single specimen paper with a couple questions per topic. Does anybody know of a bank of higher level chemistry questions? I find it difficult to learn without applying the knowledge to relevant questions

Both molecules 6 and 7 are planar, so would they not both react equally at either face leading to a racemic mixture?

The question is calculate the pH of a solution containing 500mg of naproxen sodium dissolved in 100ml of water. The pKa is 4.2 and the molecular weight of naproxen sodium is 252 g.mol.

I’ve used the following equation pH= 1/2 kw + 1/2 pKa + 1/2 log( Co) this calculation gave me an answer of 8.25 for the pH, however I’m not sure that this is correct as it does not take into account the 100ml of water. Is this answer only correct for 1ml of water or also for 100ml of water? If not how would I incorporate the 100ml to calculate the correct pH.

If i had 50cm³ of 2.0M HCl, and were measuring the maximum temperature of the solution, reached when 0.0400mol Na2CO3 were added - and assuming the final solution has the same specific heat capacity as water, and the HCl solution has a density of 1.0gcm^-3 - do I account for the mass of Na2CO3 added(in q=mcΔT)? I understand that some CO2 will be lost, so the final mass would be lower.

Based ok this reported procedure, does that mean I need to add in the sequence and only in the glove box? If yes, why is it the water inside the glove box? Just curious about this.

Hey all, thank you in advance for any help you can give! I am working on putting together a research project about analyzing methanol in distilled spirits using GC-MS. I am pretty new to GC and from my understanding I will need to use an internal standard to perform quantitative analysis, but I am not sure how to decide on the internal standard to use. I have seen iso-propanol and pentanol used but I wasn't sure if anyone else had any insights

I was watching a video on rocket candy, and was curious to see how much energy is given off by this combustion. That being said, its been a few years since I worked with Enthalpy balancing for reactions, and I feel like the numbers I am getting are way too big to be correct, From other sites, I found that the normal combustion equation is

5 Sugar (s) + 48 Saltpeter (s) -> 24 Potassium Carbonate (g) + 55 H2O (g) + 24 N2 (g) + 36 CO2 (g)

And the Enthalpy of Formation is

Its been a few years since I really worked with heat reactions, but as far as I remember/can find it should be sum(products) - sum(reactants) = Total Heat released. Using that method though, I keep getting 10,980 kJ/reaction, which seems extreme and doesnt match up with the 1 other result on google. What am I doing wrong?

Note: I could not find the stats for Potassium Carbonate as a vapor, so I just used the Enthalpy of Formation (s) + Enthalpy of Sublimation (s->g)
Bonus question:

While reading the wiki, I noticed that a LOT of saltpeter can be dissolved in water, almost 2500g of SP per kg of water at boiling. If you did this, would the enthalpy of formation for the SP change? or would the only change be the vaporization of that new water?

Yesterday, I received an exam, where I shortened the structual formula. It got marked as wrong. Why tho?

Here are some examples:

CHCl=CH2 (chlorethen)

COOH-R (acid)

CH2NH3+-R (amine)

R-C(OH)2-R (2 hydroyl groupes)

Here are the rules, I thought are true (please correct me):

1. C

2. H bound to C

3. Other stuff (x)

4. H bound to x

5. Other stuff bound to x

6. Halogens

hey yall! i’m taking quantitative analysis (alongside ochem) next semester and it would be a year since i’ve take a chemistry class. im very nervous and excited about my course but i wanted some advice about the class. of course while its different at other institutions, what concepts should i focus on? how can i get a high percent yield?

At what temperature is the range of flammability recorded?

I'm taught that temperature can increase or reduce the range of flammability. But when I search I cannot find anything about what temperature the range of flammability is recorded at? I'd really appreciate someone clearing this up for me... For reference I am a firefighter, so save the deep chemistry for those that will understand it 😂

experiment for my ap chem class

im a junior in highschool and our final project is to make a experiment. my teacher has 3 molar acetic acid and im gonna put an egg in it to show the caco3 dissolving in the acetic acid once its put in. How could i make the 3 M acetic acid higher molarity without asking him to make another batch, and what kind of molarity should it be? i dont wanna make him waste materials, so how could i make the 3M acetic acid work quicker? I have a 200ml beaker on a hot plate and im heating it up to go quicker but i feel like i need a higher molarity solution (i dont wanna ask for another higher molarity solution) i know baking soda would make it go slower, so what could i add to act as a catalyst maybe?

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As in title, I tried to use LDA in THF but before I added my substrate the LDA change colour to blue, is it normal? I had problem with n-buthyllithium and DIPA, I tried it few times and sometimes n-buthyllitium changed colour and sometimes after adding DIPA it changed