All Questions

28,654 questions
5 views

How do you convert a concentration from grams per liter to mole per liter?

How can I convert a concentration of one or more elements from for example 0.15g/l to mole per liter?
5 views

How to quantify the difference between two xyz files for the same molecule?

Sometimes I encounter xyz files with slightly different coordinates, for example, before and after optimization. What is the easiest way to compare how different are they? In the first approximation,...
8 views

Electrolysis in water with baking soda

Many demonstrations of electrolysis show the use of baking soda and a 9 volt battery for electrolysis of water. As a science experiment, I tested different voltages by adding more batteries. In my ...
8 views

Electrolysis of Potassium Iodide

Explain the change in pH durig the elecrolysis of KI using phenopthalie? I did the experiment in a U tube and the solution became pink colour in one side and the other side turned brownish red. That ...
10 views

Is it possible to prevent saponification by modifying free fatty acids?

Not big on chemistry so this question might be a bit out there. It is my understanding that a soap molecule is made up of a free fatty acid and lets say a sodium ion. Correct? Would it be possible to ...
14 views

What risks could arise from a piece of plastic falling into boiling water when cooking?

What risks could arise from a piece of plastic falling into boiling water when cooking? My understanding is that the main risks could be due to leaching of additives in the plastic product rather ...
9 views

Why aldehydes have a lower boiling point than alcohols? [on hold]

In the following question 22, answer given is option b That is alcohol having a greater boiling point than aldehyde But intra molecular hydrogen bonding plays a role in aldehyde.. Then aldehyde ...
19 views

Solubility of copper(I) iodide in potassium iodide solution

Calculate the solubility of $\ce{CuI}$ in a $\pu{1.0e-4 M}$ $\ce{KI}$ solution, knowing that $K_\mathrm{sp}(\ce{CuI})=\pu{1.1e-12}$ and $K_\mathrm{s2}$ of the following reaction is $\pu{7.9e4}$. ...
25 views

ORGANIC CHEMISTRY [on hold]

At the beginning I use EtO- to remove H between 2 ester groups and then I attack it with a SN2 and remove Br
14 views

insoluble glue in acetone and alcohol

I am trying to make a tissue specimen for scanning electron microscopy. What I am looking for is a glue which isn't dissolved by both alcohol and acetone. Do you know of any?!
19 views

Need help with mole question [on hold]

A compound is 82.2% nitrogen and 17.8% hydrogen. There are 2.461 x 10^20 total atoms present in a particular sample. Find the number of molecules, moles and grams. I determined that formula is NH3....
13 views

How to randomly label DNA?

I am wondering how to randomly label/modify internal sites (i.e. not the ends) of a double-stranded DNA molecule, either on the sugar-phosphate backbone or on the bases. Enzymatic processing would ...
16 views

Balance redox reaction [on hold]

NO3- + H2S. ---->. H2SO4-. +. NH4 Balance the given reaction
23 views

Which of these compounds reacts with ethylmagnesium bromide and also decolourizes bromine water solution? [on hold]

Question: Options: 1) 2) 3) 4)
15 views

Bond Nature of a comound [on hold]

How can we determine the type of Bond in LiBaPO4? can we find out the nature of bond through charge transfer values of these elements? if yes then how?
20 views

When does a continuous and a line spectra occur?

Its said that nuclear atomic model was rejected as according to it the electrons should radiate continuous spectra. But they radiate line spectra. My question is that line spectra is emitted when the ...
11 views

CErawool and heat retention capacity

I am from Gujarat and we are running an industry of Polymers cracking. We use LPG gas as the medium of energy. we have refractory where we infuse the gas and air to fire the heat, bring it up to 850c. ...
13 views

Heat Exchange questions thermochemistry [on hold]

An average person produces about 2500 kcal (heat) a day due to metabolic processes. A) What will be the increase in body temperature of a person a day if we assume for a moment that it is a closed ...
17 views

Reactions in chemistry [on hold]

What would be observed if copper (11) sulphate solution was treated with potassium hydrogencarbonate solution ? Plus the equations involved.
20 views

Equilibrium constant vs Equilibrium position [duplicate]

In my book, a statement is written as: " Kc is Equilibrium constant and has a constant value at a particular temperature Whereas the ratio of products to reactants is described as the position of ...
21 views

Copper Mirror Reaction

I would like to create a copper mirror on a plate of sandblasted glass. I know that a reaction exists: $$\ce{CuSO4 + N2H2 -> Cu + N2 + H2SO4}$$ I know that such a plate of copper is very weak. ...
34 views

Compound, Ascorbic acid: What implies the dotted line? [on hold]

What implies the two dotted lines? Why has the two carbon on the left side 3 free electrons? With C₆H₈O₆ not all carbon atom is connected. What is the topic which describes how to read and understand ...
29 views

what is the exact meaning of oxidation state? [duplicate]

can you mention the concept of oxidation state without its simple definition i-e it is the apparent charge +ve or -ve.....😪 I found these in wikipedia but didn't understand."Conceptually, the ...
36 views

Why does bond breaking in ATP release energy? [duplicate]

We always come across that formation of bonds releases energy, and bond breaking requires energy, but in the case where ATP converts into ADP or AMP (bond breaking), energy is released. Why? Further, ...
17 views

why do I get chlorine gas production during electroetching?

I was electroetching stainless steel plates with table salt as electrolyte and the power supply was providing 5V, 6A when I placed the anode and cathode about .25 inches apart. I started smelling a ...
14 views

Which etching process is better, photochemical or electrochemical?

My boss and I are experimenting with several different ways to micro machine .01" and .005" stainless steel. When I look up how it's done professionally, I see an overwhelming majority of companies ...
19 views

How Can I make Make 0.1M Mercury nitrate solution? [on hold]

I dissolved 14 grams of Mercury nitrate dihydrate in 200 ml water and diluted to 250 ml. the solution is cloudy and seems that is not dissolved. any suggestions?
23 views

How much does steam expand in relation to its temperature (assuming starting at 100 °C) and constant pressure in a flexible container? Thanks! [on hold]

How much does steam expand in relation to its temperature (assuming starting at 100 °C) and constant pressure in a flexible container? For example, if 1 L of $\ce{H2O}$ expands to about 1600× the ...
19 views

Why enzyme-catalyzed reactions mostly go one way?

I listened to the lecture about enzymes. Professor downplayed the question in the subject. He said that enzymes are able to work both ways, but practically speaking reactions with overwhelming ...
29 views

Balancing an equation

so I might be just way to tired for this, but I somehow have a stupid mistake here when trying to balance an equation. $$Zn(s)+MnO_2(s)+NH_4^{+}(aq)=Zn^{2+}(q)+Mn_2O_3(s)+NH_3(aq)+H_2O(l)\tag{1}$$ ...
26 views

Aromatic NMR in benzyl alcohol [on hold]

Do you know the multiplicity of aromatic hydrogens in benzyl alcohol? In many files on internet I see "5H multiplet" but I want more precision please.
45 views

Angular momentum of an electron in an atom

The Orbital Angular momentum of an electron in an atom is given by $\hbar \sqrt{l(l+1)}$ and the Spin Angular Momentum is $\hbar \sqrt{s(s+1)}$. So what is the resultant Angular momentum of an ...
54 views

why HI isn't fully miscible with cold water when HF is?

HF is more soluble in water than HI , due to greater hydrogen bonding in HF , accepted but, on the other hand HF is a very weak acid so it's dissociation will be meagre when compared to HI's ...
20 views

Changing the CO2 concentration (adding or subtracting) inside a sealed vessel?

I am looking for a method of modifying the CO2 concentration inside a sealed container that is both precise and repeatable (C02 needs adjustment every time the container is sealed, also need to be ...
25 views

Creating a pressure vessel to make emeralds and rubies/sapphires

So I understand that this is going to be a very difficult thing to properly do but I am looking to create a vessel for growing crystals. I am not looking to build a Verneuil furnace bit rather a ...
11 views

Why would red wine 'fixate'a bronze patina?

The author of this article experimented with various ways to create a patina on a bronze watch. The very last method he tried was soaking it in milk for a few hours, creating a sort of iridescent ...
13 views

What condition would be used in laboratory [on hold]

What condition would be used in the laboulatory to hydrolysed disaccharide in monosaccharide component
10 views

Solubility of substances in HF; High Solubility of Substances in Most Hydrogen-Bonded Compounds [on hold]

Across my chem course, I noticed that HF does not dissolve several ionic and covalent compounds. What sort of compounds are soluble in HF? Or do no compounds dissolve in it? And why are hydrogen-...
44 views

Which Carbocation is most stable among the three? [on hold]

According to me the answer should be (C) as that Carbocation will be stablized by resonance with Chlorine. I have read that resonance is the biggest deciding factor about the stability of a ...
38 views

Slope of Graph of Wave Number vs inverse square of the principal quantum number(1/n^2) in Hydrogen Emission spectrum

What is the final expression we get for wave number in a hydrogen emission spectrum? Let us say for example from 6 to an orbit $n$. Considering that it is an emission spectrum, I think it would be ...
20 views

Buffer Capacity Equation

Whilst doing buffer capacity, my lecturer presented us with the following equation for buffer capacity: $${log(\frac{[salt] + x}{[acid] - x})} = 1$$ A task set by the lecturer is to rearrange the ...
19 views

Half life of A in the first order reaction 2A+B-> Products [on hold]

In the reaction 2A+B->Products, if Rate=k[A] and k=0.0693 then what is the time taken to consume half of A? Can someone please provide a solution to this question? Regards, Apoorv
22 views

What metal is this???Brass patina, turned grey!

I have this piece for a long time. It has always been a brass like color. It was very dirty so I decided to clean it up. To my surprise after sanding it became grey, almost silver like color. I ...
10 views

Correlation energy in quantum chemistry

In DFT there is classic Coulomb energy and non-classic correlation energy. But what is difference between them? In books these energies are explained very similarly. Both contributions are explained ...
35 views

Why enthalpy is defined at a constant pressure?

How absolute enthalpy and enthalpy change are defined? What is the clear difference between enthalpy and heat? Is it the constancy of pressure what makes the enthalpy a state function? My teacher ...
19 views

Source: The1stLawofThermodynamicsLesson4 I am looking for difference between adiabatic expansion and Joule-Thomson effect. Looking at the setup demonstrating Joule-Thomson effect, I find no essential ...
19 views

Aqua complex scarcity for transition metal ions of second and third row

I've read that for the second and third row of the transition metal ions, almost no [M(OH$_2$)$_6$]$^{2+}$ or [M(OH$_2$)$_6$]$^{3+}$ complexes are known, while they're very common for the first row. ...
19 views

Why concentration of water is not taken 1 for the equilibrium constant of esterification reaction? [on hold]

For pure liquids and pure gases, we approximate the concentrations equal to 1. In case of the esterification reaction, why do we write $\ce{H2O(l)}$ in the $K_\mathrm{c}$ formula since we have ...
If you are provided with the aqueous solutions of the following: $\ce{NH3}$, $\ce{NaOH}$, $\ce{Na2CO3}$, dilute $\ce{HCl}$, dilute $\ce{H2SO4}$, dilute $\ce{HNO3}$ And you are required to separate ...
Q.15 the major product of the following reaction is: I have read that $\ce{NaBH4}$ reduces only aldehyde, ketone and acid chlorides. In some cases it may reduce double bonds conjugated with ...