# All Questions

30,339 questions
Filter by
Sorted by
Tagged with
16 views

### Enthalpy of formation at other temperatures

I was told each compound has an enthalpy of formation of 0 at the standard temperature if it is in it's lowest energy modification. But what if we change the temperature? It would make sense to me ...
34 views

### What is the major product obtained on acidification of substituted epoxide?

The problem Source : MS Couhan (problems in organic chemistry . Chapter: Alcohols , phenols and ethers). My Thoughts If I proceed along $\ce{path 1}$ , $\ce1a$ is formed . It is unstable due to ...
26 views

### How determined the amount of acetic anhydride and pyridine that was added to the polyimide synthesis solution?

I want to synthesis a polyimide from a diamine and a dianhydride in lab scale via polycondensation reaction, in this route in the second step, acetic anhydride and pyridine are added to the reaction ...
22 views

### Has there been any independent verification of the results from this Chinese nanotube study?

Watts up referred to the South China Morning Post in reporting that a Tsinghua University team led by Wei Fei claimed in 2018 to have manufactured carbon nanotube fibre has tensile strength of 80 ...
47 views

### Why will A atoms diffuse from β phase to α phase and B atoms from α phase to β phase?

At the initial compositions 1 and 2 of $α$ and $β$ respectively the chemical potentials of A and B atoms in each phase can be found by extrapolation of the tangents to the free energy curves at 1 and ...
24 views

### Is there a known relation between the diffusion of a molecule and the diffusion of the reactants?

I have a plasma consisting of elements A and B (which have a similar mass). These elements can react to form molecules AB. $$\ce{A + B -> AB}$$ Now if my plasma or gas is expanding based on ...
16 views

### Does the presence of oxydation agents like O2 prevent the conversion of tert-butanol to isobutylene? [on hold]

In the presence of $\ce{O2}$, does tert-butanol still convert into isobutylene catalyzed by strong acid resin? Do other conditions prevent this conversion? You're actually dealing with tert-butanol, ...
17 views

### What metals do not form 1:1 complex with EDTA? [on hold]

Except for group 1A metals, which are very hard acids, what other metals do not form 1:1 complex with EDTA?
28 views

### Why does a system want to achieve randomness to be feasible? [on hold]

According to entropy and gibbs free energy, randomness is one of the factors that determines reaction spontaneity, but why? Shouldn't it be the opposite?
37 views

### What chemical or material could attract plastic?

I'm looking for a material that is affordable, around the 100 USD per kilogram. I'm thinking of a chemical that kind of attracts plastic like a magnet. Microplastics is the type of plastic that I'm ...
11 views

### How can determine galactose and mannose by GC-MS if its elute same RT in 5MS column? We have only galactose standard

How can determine galactose and mannose by GC-MS if its elute same RT in 5MS column. We have only galactose standard and galactose only should quantityfy, but the peak of galactose standard also ...
19 views

### How is the answer for the given question is 1 and not 2nd Option?

The answer should be 2 right? Since as P and V are inversely related. So the PV should be constant.
96 views

### In the last step of Kjeldahl Method, is the reaction of ammonium to NaOH not taken into account?

In the last step of Kjeldahl method, the unreacted $\ce{HCl}$ in the solution is back titrated with a standard $\ce{NaOH}$ and the concentration of $\ce{HCl}$ that has been used to neutralize the ...
46 views

40 views

### Lowering the melting point of water with salt

I was trying to calculate amount of salt needed to lower the melting point of water by 5 °C. According to my solutions, I need to make sure $$n\mu(\ce{H2O(s)}) =n\mu(\ce{H2O(l)})+ RT\log(x)$$where \$ x=...