# All Questions

28,650 questions
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### Blue color in the blue persian salt [duplicate]

Blue persian salt has tiny blue framgents. So far I could found two explanations: It is sylvinite mineral inclusions As said in Wikipedia, "The intriguing blue colour occurs during the forming of ...
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### Attack of 3-methylbutan-1-ol on benzene in acidic medium

That's how I proceeded with the question. However the answer is tert-butylbenzene. I can't figure out why do I have an extra carbon atom. SOURCE - JEE Advanced 1994
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### Meaning of red heat

I have two reactions below. What is the difference between red heat and normal heat? Is it related to iron as a catalyst when it is red hot?
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### What is the role of ammonium chloride in the workup of a Grignard reaction?

In the following Grignard reaction, why is aqueous ammonium chloride used to get to the products? I don't see how it participated in or modified the reaction from what is normally expected.
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### How to calculate oxidation states for a complex ion? [on hold]

How to calculate oxidation states for $\ce{[Co(NH3)4Cl(NO2)]Cl}$?
I recently looked for aluminum source/contamination that migrates to agriculture soil. The toxic form of $\ce{Al}$ to plants is $\ce{Al^3+}$. Are there any of $\ce{Al}$-containing compounds (e.g. $\ce{... 0answers 11 views ### How do you get adding propene from the addition of warm ethanolic sodium hydroxide to 1-bromopropane? [on hold] from May June 2015 paper of AS Level Chemistry (Cambridge International Examinations) Question number 24 of 9701_s15_qp_12 0answers 28 views ### Isotopic exchange of oxygen Since we know that ketones and aldehydes show the reaction below I have a doubt that whether such reaction is shown by esters. Beacuse my chemistry teacher told so, but I didn't see it Solomon's, ... 0answers 7 views ### How to calculate ΔrHm? [on hold] The question in regard is written as follows: Using the following reactions, calculate ΔrHm. a)Fe2O3 + 6HCl = 2FeCl3 + 3h2O b)Fe + 2HCl = FeCl2 + H2 0answers 19 views ### How do you convert a concentration from grams per liter to mole per liter? [on hold] How can I convert a concentration of one or more elements from for example 0.15g/l to mole per liter? 2answers 39 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,... 0answers 32 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 ... 0answers 11 views ### Electrolysis of Potassium Iodide [on hold] 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 ... 2answers 48 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 ... 0answers 18 views ### What risks could arise from a piece of plastic falling into boiling water when cooking? [on hold] 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 ... 0answers 23 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 ... 0answers 28 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}$. ... 0answers 39 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 0answers 17 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?! 0answers 22 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.... 0answers 19 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 ... 0answers 19 views ### Balance redox reaction [on hold] NO3- + H2S. ---->. H2SO4-. +. NH4 Balance the given reaction 0answers 41 views ### Which of these compounds reacts with ethylmagnesium bromide and also decolourizes bromine water solution? This question was asked in an exam and the answer in the official answer key was option 3. Which of the following compounds reacts with ethylmagnesium bromide and also decolonizes bromine water ... 0answers 17 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? 0answers 29 views ### When does a continuous and a line spectra occur? [on hold] 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 ... 0answers 12 views ### CErawool and heat retention capacity [on hold] 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. ... 0answers 14 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 ... 0answers 19 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. 0answers 22 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 ... 0answers 26 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. ... 1answer 38 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 ... 2answers 31 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 ... 2answers 44 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, ... 0answers 19 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 ... 1answer 21 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 ... 0answers 20 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? 0answers 26 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 ... 1answer 23 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 ... 1answer 32 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. $$Zn(s)+MnO_2(s)+NH_4^{+}(aq)=Zn^{2+}(q)+Mn_2O_3(s)+NH_3(aq)+H_2O(l)\tag{1}$$ ... 0answers 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. 1answer 49 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 ... 1answer 62 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 ... 0answers 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 ... 0answers 26 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 ... 0answers 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 ... 0answers 14 views ### What condition would be used in laboratory [closed] What condition would be used in the laboulatory to hydrolysed disaccharide in monosaccharide component 0answers 14 views ### Solubility of substances in HF [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? 2answers 56 views ### Which Carbocation is most stable among the three? [closed] 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 ... 1answer 44 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 ...
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 ...