All Questions

If we consider U-235 (Uranium-235) , the mass of protons and neutrons in the nucleus combined together is more than the calculated atomic mass of the nucleus . Why is it so ? (Whereas For C-12 (...

I am quite a beginner in DFT and I am studying the theory behind the computational tools. I have some doubts about the Columb approximate functional term: $U[n] = \frac{1}{2} \int d^3 r \int d^3 r^\...

I did a school experiment to measure the heat of solution (enthalpy) of various salts dissolved in water. My results are completely different to the teacher's answer. Specifically my test showed ...

Please if anyone can help me, I was in a class with my lecturer when he mentioned that the formula for rate constant in first order reaction is this In which what I know recently is that the rate ...

In my project, I need to measure ph, turbidity, and free chlorine content in treated water from wastewater, I found sensors for ph and turbidity but when I search for chlorine sensor, I found it but ...

Is there any Pythonic way (a.k.a: a module, an rdkit package, etc) or an API I can use for ADME predictions? I need to prioritize some compounds for purchase/synthesis and some sort of ADME scoring ...

Seeing Copper has an exceptional electron filling in its valence shell(4s1 3d10), the way I see it is that on +1, a d10 configuration should be more stable and hence easier to attain than a d9 which ...

I am studying statistical mechanics and force-fields, and I see a lot of this formula being thrown around with no explanation: $$U_{\mathrm{dihedral}} = \begin{cases} k(1+\cos (n\psi + \phi)),&...

If all the excited molecules at higher S1 vibrational states rapidly relax to the lowest S1 vibrational state, why do the fluorescence transitions from v' = 1, v' = 2, v' = 3, and other states to v&...

I'm coming into my first year at a 4-year university after finishing my associates at a two year school. I think that I am interested in focusing on materials science, I feel like there is still so ...

High school chemistry student here. Currently, we are learning stoichiometry and I noticed that when we calculate the limiting reactant of a reaction with multiple products, we almost always just take ...

I've read some answers online but I still can't seem to understand the mirror image effect. Why is the highest energy absorption (v" = 0 to v' = 4) the lowest energy fluorescence (v' = 4 to v&...

I measured the change in pressure for the decomposition of hydrogen peroxide in the presence of a manganese(IV) oxide catalyst at 5 different temperatures: $$\ce{2 H2O2 (l) ->[MnO2 (s)] O2 (g) + 2 ...

Why would concentration of the electrolyte and not the type of electrolyte used affect current density in an electrolytic cell because I believe the mobility of the ion does have an effect on current ...

My IB Chemistry class needs to have our Internal Assessment ideas finalized by next week, and I'm torn between a few experiments. I'm considering performing an oxidation of ethanol and potentially ...

I am trying to figoure out the conditions and choice of solvents and catalysts in order to run this synthesis.

After investigating what makes the persistent radical TEMPO stable, I was wondering if another compound which is more feasible for my needs would be comparable to it. Would oxidizing 2,2’-dimethyl-...

Is there a way to keep Cl2 gas very low in a 55 gallon drum? HOCl is stored in it and there is some Cl2 off gassing in top headspace. Was wondering if there was anything I could use in one of the bung ...

Sorry don't know if this is more for physics or here, essentially I had a question on the root mean square velocity of gas particles equation and didn't know what it was so tried to work something ...

I am writing a story about a planet that is covered in water but the water is closer to a gel-like substance with a higher concentration of salinity than EO water. I just wanted to know if that was a ...

I am working through some MIT lecture notes trying to understand adiabatic flame temperature. There is a section in these notes where $K_p$ is calculated for the following reaction at $\pu{1600K}$. $$\...

I observed a sharp decrease in the current when I carried out the electrolysis of water. Just to set the context, I used a voltage of $\pu{12V}$ and the concentration of my electrolytes were $\pu{0.15 ...

Methyl methacrylate was polymerized at a mass concentration of 200 g dm−3 in toluene using azobisisobutyronitrile as initiator at a mass concentration of 1.64×10−2 g dm−3 and a reaction temperature of ...

My first question has to do with the fact that Hydroboration produces an anti-markovnikov product, why?. I don't see how that happens. A wikipedia artical says that B has a partial positive charge ...

What role do ions like $\ce{Ca^{2+}}$ and $\ce{Sr^{2+}}$ as electrolytes play in the electrolysis of water (how do they contribute to current when they don't take part in electrode reactions) and how ...

The iterative method I have learned to make flash calculations for a binary system where I know the inlet feed (F [mol/s]), total composition of the two components ($z_1$ and $z_2$), the amount of the ...

3-ethyl-4-methylhexa-1,3-diene undergoes a combustion reaction. For this reaction, the following concentrations were used: [O2] = 0.06 M, [CO2] = 0.09 M and [H2O] = 0.10 M. Determine the concentration ...

I have run into what I imagined would be simple mathematics, but it turns out I need some help. My problem is I have a bottle of Geobacillus stearothermophilus and the concentration of the spores is $\...

I have some water-soluble crystalbond that is attached to silicon and, because of some overheating (to about 150 Celcius) during a final processing step, the crystalbond seems to have charred (white/...

From the chemical structure of acac- compared to NH3 and en, is acac- a stronger or weaker ligand strength? How and why do we know this?

good day , I have a problem precipitating metals from aqua regia solution that I have made from an ore , it does changes the color when I dip some stannus chloride in to the beaker . But does not give ...

I wanted to know if I can nurture a bacteria which is not difficult to find and with time I can train them on harsh chemicals and soon introduce plastic into it with the hope that it will eat it up ...

I have a question how can we compare gas or solvent phase DFT calculations properties with experimental solid/crystalline phase properties? How can we validate our theoretical methods? Thanks, Shen

I'm having a hard time understanding what equivalent weight means physically. I've looked at many articles on Google but the definition always seems nebulous to me. For example, if the equivalent of $...

If we were to consider the vaporization of liquid water to gaseous water, my instructor stated that it would be "possible to estimate the enthalpy of vaporization based on differences in bond ...

I'm having difficulty understanding why the base-centered orthorhombic crystal system is a unique crystal system. When I draw two base-centered orthorhombic unit cells next to each other there appears ...

although they are in the same group? Why $\ce{K2CrO4}$ Potassium chromate is a good oxidizing agent but $\ce{K2MoO4}$ Potassium molybdate is not?

I knew that we have a stereocenter if the carbon is bonded to four different groups. According to the stereocenter rules, I should have $\ce{CH2}$ bonded to the carbon of the stereocenter (marked with ...

I have a bathtub that I accidentally poured wood stain into. Now the stain is all over the white ceramic surface of the tub. I tried using bleach but it didn't do anything. I'm curious if there is a ...

I am looking for a brief explaination on this, or a source that explains this more.

$\pu{48g}$ of graphite and $\pu{16g}$ of $\ce{O2}$ is given. The question is to count the no of molecules of $\ce{CO2}$ produced? Now, the solution in book is this No of $\ce{C}$ atoms = $\frac{\pu{...

Is that caused by sweat? Kinda confused.

Phenolsulfonic Acid( PSA) is produced after sulphonation of Phenol at around 100 degrees. They use this product in tinplating. Once a stable PSA is formed after sufficient reaction , unreacted ...

Electron affinity of atoms in the same row usually increases with the atomic number until the shell or half-shell gets full, and then it drops down. Some transition metals are exceptions from the rule,...

Though some structures are available on the net, different sources are showing different structure, so please share the actual structure of $\ce{K3CrO8}.$

Problem How can we qualitatively compare the bond lengths between $\ce{H2O2}$ and $\ce{O2^2-}?$ Answer Attempt I tried using molecular orbital theory, but since both have peroxide $\ce{O2^2-},$ the ...

I have been given a problem to derive a relation for change in entropy from change in Gibbs free energy: Starting with the isothermal equation $$G(p_2) = G(p_1) + nRT\ln\frac{p_2}{p_1}\label{eqn:1}\...

I have measured $\mathrm{pH}$-values to these solutions and filled in a table: $\ce{NaCl}:9.5-10$, $\ce{CH3COONa}:8$, $\ce{Na2CO3}:11.5$, $\ce{NaHCO3}:2$, $\ce{KNO3}:3$, $\ce{NH4Cl}:7-8$ The question ...

Is an inverted reverse osmosis leading to hydride in h2o ?

During an addition reaction of an alkene, how does a double bond break to form two bonds with the two atoms of the reactant plus a bond between the carbon atoms? Not sure if this is a silly question ...