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26 views

Why can't sodium borohydride reduce carboxylic acid and ester groups?

Sodium borohydride ($\ce{NaBH_4}$) is a reducing agent used in various organic reaction to reduce aldehydes, ketones and acyl chlorides. Why can't sodium borohydride reduce carboxylic acid groups and ...
1
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1answer
75 views

Does the position of a functional group in an organic compound have any effect on the compound's heat of combustion?

Is there a link between where the functional group is located in an organic compound and the compound's heat of combustion? It has been mentioned before that it is difficult to accurately get the ...
0
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1answer
25 views

Which of these can undergo decarboxylation reaction readily

Which of these carboxylic acids can undergo decarboxylation readily? According to what I know beta-keto acids undergo decarboxylation easily and readily due to formation of a stable intermediate. So ...
2
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1answer
1k views

Using Dalton's law of partial pressure to find percentages of composition

A mixture of helium and neon gases is collected over water at $28.0 \rm~^\circ C$ and $745\rm~ mmHg$. If the partial pressure of helium is $368\rm~ mmHg$, what is the partial pressure of neon? (Vapor ...
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0answers
11 views

How to make SiC (silicon carbide) at home?

I have found this wikipedia page talk about Acheson process, the simplest way to make SiC. But can I really do something like that in my house? I just want to make some LED myself from SiC (not just ...
0
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1answer
41 views

Which process would separate the mixture of toluene, cyclohexane and water?

toluene: $\ce{C6H5-CH3}$ cyclohexane: $\ce{C6H12}$ I think that answer would be: Toluene and cyclohexane do not dissolve in water (since they are nonpolar), so I would first separate the water from ...
1
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0answers
10 views

Glycerin yield upon saponification of beeswax

I am making a custom grease (castor oil & sodium stearate) that will be suspended in beeswax. I have found that saponifying some beeswax for use in the grease results in higher operating ...
-1
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1answer
38 views

What is the name of a reaction that produces 3 compounds? [closed]

I was wondering if anyone knows what kind of reaction the following is: $$\ce{Na2SiO3 + 6HF -> SiF4 + 2NaF + 3H2O}$$
8
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3answers
53k views

Why doesn't copper react with hydrochloric acid while the other metals do?

5) Which one of the following metals does not react with hydrochloric acid? A. zinc B. magnesium C. iron D. copper E. aluminium The right answer must be copper, but why ...
0
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2answers
28 views

Why are enthalpy of combustion and molar mass of organic compounds proportional?

I noticed that when you graph heat of combustion against molar mass, you get a completely straight line with a correlation of 1. I know that the longer the chain is, the stronger the LDF get, so it is ...
0
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0answers
13 views

How to generate accurate displacements along normal modes?

How can i displace my structure along a particular normal mode, without coupling to other modes ? Rather than a exact mathematical procedure, I am more interested in a software/script/package that can ...
12
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1answer
2k views

Why does hydrogen burn with a pale blue flame while its emission spectral lines are red in colour?

I was studying oxidising flames and realized that sodium burns with a bright yellow flame the wavelength of which is around 588 nm. Then I searched for emission spectra of sodium and found that the ...
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0answers
20 views

Vanadium redox battery… why not nitrogen redox battery OR iron redox battery?

Vanadium redox battery operating on $$ \begin{align} \ce{V^2+ -> V^3+ +e-}\\ \ce{VO2^+ +e- +2H^+ -> VO^2+ +H2O} \end{align}$$ because Vanadium has multiple oxidation states. How about nitrogen ...
-1
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0answers
16 views

Normal melting point

Consider the following data for a substance: Critical point: 114.3 atm and 561°C Triple point: 0.108 atm and 114°C Normal melting point: 1.00 atm and 124°C What is the normal boiling point of the ...
2
votes
1answer
75 views

What is the mechanism of formation of alkali metal superoxide?

I was studying about alkali metals. I can get how oxides and peroxides are formed. In alkali metal oxides, both of the bonds of the dioxygen molecule first undergoes homolytic cleavage, then the ...
14
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1answer
5k views

Order of dipole moments

What is the order of dipole moments for $\ce{SO3, SiO2, P2O5,}$ and $\ce{Cl2O7}$? This question is from a book and the answer given is $\ce{Cl2O7 < SO3 < P2O5 < SiO2}$. Can someone explain ...
4
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0answers
50 views

How to use Sodium Thiosulfate for fixing dicopper (I) tetraiodomercurate (II)?

DISCLAIMER DO NOT TRY TO DEMERCURATE USING DESCRIBED PROCEDURE. CONSULT YOUR EMERGENCY SERVICE. I found a discrepancy between a government-approved procedure of living quarters demercuration and the ...
3
votes
1answer
77 views

Rate law for A + B → C → P

I need some clarification for the following assignment: Derive the rate law for $$\ce{A + B -> C -> P}$$ when $\ce{A + B -> C}$ is the slowest step and very slow. My understanding is $\ce{A ...
0
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0answers
15 views

Relation between hydrolysis constant and concentration of solution

Is hydrolysis constant independent of concentration of solution or dependent on concentration of solution? I have read two differing concepts on it.. NCERT CHEMISTRY BOOK SAYS IT IS INDEPENDENT.. But ...
2
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0answers
19 views

Toxicity of Mercury (II) Iodide and dicopper (I) tetraiodomercurate (II)

This is a continuation from my previous post. Could you please give me some info on the toxicity of compounds $\ce{HgI2}$ and $\ce{Cu2[HgI4]}$? I found on sigmaaldrich.com that these are very ...
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0answers
19 views

Chemical properties of dicopper (I) tetraiodomercurate (II)

This is a continuation from my previous post. Where can I find information on the chemical properties of $\ce{Cu2[HgI4]}$? I found a mention that in reaction with $\ce{Na2S2O3}$ in presence of acid ...
-1
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1answer
50 views

Can the guanidinium ion give stable N-nitrosamines under mild metalworking conditions?

Can the guanidinium ion react with inorganic nitrite under mild basic metalworking conditions ($\mathrm{pH\ 8 - 10}$ and temperature $\lt \pu{70^\circ C}$) to give stable N-nitrosamines? Usually, the ...
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0answers
22 views

How does the blue color of starch solution change depending on temperature and what is the cause for this?

I was doing a project for my school and im not sure the following answer is correct: "After adding iodine liquid to starch solution the colour turns blue. By heatig the mixture loses its colour. &...
3
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1answer
8k views

Is an antiaromatic compound more stable than a non-aromatic compound because of more conjugation?

(image from a LibreTexts page (archive link)) It is shown that the antiaromatic compound is more stable than the non aromatic compounds 2 and 3 because of a more conjugated system. Here's the exact ...
5
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1answer
58 views

What is the maximum number of water molecules that has been recorded till date to present as water of crystallization in a compound?

Context: I was casually looking through some old questions when I found this question. The OP wanted a compound that has all the hydrates ranging from monohydrate to decahydrate. I found chromium(III) ...
2
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0answers
34 views

Choosing hyperconjugation when resonance doesn't give a reason for stability

Which of the following structures would be least stable? I initially approached it like this: As both are allylic carbocations, and that both are in fact resonating structures of the same molecule, ...
-2
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1answer
31 views

Explanation of rusting of iron through metallic bonding

1 ) [O - oxygen atoms , red dots - electron ] Explaining rusting of iron due to metallic bonding. So , here delocalisation of electron happens between Fe and Fe atoms. After some time , there is ...
6
votes
1answer
308 views

Why don't beryllium and magnesium dissolve in ammonia?

From my textbook: The [alkali and] alkaline earth metals dissolve in liquid ammonia to give deep blue solutions forming ammoniated ions. $$\text{M}+(x+y)\text{NH}_3 \rightarrow [\text{M}(\text{NH}_3)...
2
votes
1answer
26 views

Are the orders of reactants with respect to a reaction different for different starting concentrations?

I have found the rate constant and found that the orders of ethyl iodide and pyridine are both 1 with respect to the reaction when their initial concentrations were both 0.1 M. I would have thought ...
3
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4answers
862 views

Justify assuming first-order kinetics for a complex

For the hydrolysis of $trans-\ce{[Co(en)2Cl2]Cl}$ (and cis) we measured reaction rates via spectrophotometry. Plots of change in absorbance $(\ln(A-A_\infty))$ were used to determine the rate law and ...
0
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1answer
22 views

Reasoning for redox reactions to be classified as such

Could anyone help me out solving this question regarding redox reactions? I am fairly new to this topic. Which of the following is a redox reaction? (1) $\ce{NaCl + KNO3 -> NaNO3 + KCl}$ (2) $\ce{...
0
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0answers
16 views

Reaction of but-2-ene with Cl2/CCl4

I have often studied the reaction of Br2/CCl4 with But-2-ene which results in formation of But I wondered what would be formed if Cl2/CCl4 reacts with But-2-ene. Does it lead to the formation of ...
3
votes
1answer
167 views

Finding order of acidic strength for given compounds

The decreasing order of acid strength of the following compounds: The given compounds are Water ($\ce{H2O}$) Ammonia ($\ce{NH3}$) Acetylene ($\ce{C2H2}$) Triphenyl system ($\ce{Ph3CH}$) a) $\ce{NH3}$ &...
1
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2answers
57 views

Triple Point of a compound and critical point

Is it necessary for all compounds to have a triple point? Also, how is the triple point determined? Suppose a substance does not have a triple point, so how do researchers agree on the impossibility ...
7
votes
3answers
6k views

Where to find data for Gibbs energy, enthalpy, and entropy?

Where can you find the enthalpy and Gibbs free energy of formation and entropy of compounds either as a data file or web API? Technically, I only need two since I can figure out the other one from two ...
0
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0answers
6 views

Chemistry database for Gibbs energy [duplicate]

Is there good databases for Gibbs energy and other thermal properties? NIST WebBook is okay but easier to browse most common chemical elements like hydrogen, water, oxygen and so on in a table or ...
0
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1answer
31 views

Determining whether a compound is ionic or molecular in nature

$\ce{HCl}$ is a molecular compound because there is a covalent bond between $\ce{H+}$(a proton) and $\ce{Cl-}$ (a chloride ion) $\ce{NH4NO3}$ is an ionic compound because there is an ionic bond ...
2
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1answer
32 views

Reason for triphenyl methane being less acidic than acetylene

This question came through answering a question that talked about the acidic order of four compounds. Upon researching the actual $\mathrm p K_\mathrm a$ values I noticed that even though there was a ...
2
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1answer
22 views

Thermodynamic properties of enantiomers

Pairs of enantiomers have the same chemical and physical properties (except rotation of plane polarized light) within an achiral environment. However, I am curious about the thermodynamic properties ...
1
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0answers
14 views

Temperature relation with concentration and volume

Q. Standard enthaply change for the reaction of calcium hydroxide with hydrocloric acid was found by reacting $\pu{0.0100 mol}$ of solid calicum hydroxide with $\pu{50 cm^3}$ of a $\pu{1.00 mol/dm^3}$ ...
3
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0answers
27 views

Does a geminal or vicinal diiodide form upon addition of excess HI to but-2-yne?

Reaction: $\ce{CH3-C#C-CH3 + HI (excess) -> ?}$ Product : I thought of different carbons by the reasoning from this post earlier I posted. But it is given that both iodine atoms exist on the same ...
0
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0answers
26 views

Given initial moles of weak acid, find moles of conjugate base to be added to get a final pH (volume unknown)

I am preparing notes on buffers and I came across this problem on a website: Given 10.0 mmol of a weak acid HA with $\textrm{p}K_a =5$, how many mmol of NaA needs to be added to have a final $\textrm{...
4
votes
1answer
64 views

Can sodium borohydride reduce hemiacetals?

In the synthesis of Panacene by Canesi et al. [1], a step involves the installation of an -OH group on a double bond, using the oxymercuration-demercuration procedure. However, the product happens to ...
-1
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0answers
29 views

Why do only cations move into interstitial sites in Frenkel Defect?

I have learnt that cations move into interstitial sites due to their smaller size in comparison with anions according to my teacher when learning about crystal defects today. My question is, why ...
1
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0answers
17 views

HOBt and DCC in the synthesis of peptides

DCC is a well known reagent used for the synthesis of peptides, aiding the formation of the amide bond by forming an intermediate with the carboxylic acid that contains a leaving group. During my ...
2
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2answers
3k views

Why are more electronegative atoms better leaving groups?

My book says, "halide anions are electronegative and can easily stabilise negative charge, hence are good leaving groups." What exactly does "stabilising negative charge" mean? I ...
0
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0answers
9 views

How reliable would commercially available starch be as a standard for an experiment?

I am conducting a student experiment of finding the amylose to amylopectin ratio of certain samples using an iodine colorimetry method. In order to calculate the actual ratios, I need a standard to ...
0
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1answer
49 views

Kohlrausch's Law

What is the proof of Kohlrausch's Law of Independent Migration of Ions? How did Kohlrausch calculate the limiting molar conductance of a weak electrolyte? I am asking this in context of ...
3
votes
1answer
125 views

Reaction of haloalkane with hydroxide ions

My teacher gave me the following question: What are the possible products of these reactions? Then, what is the mechanism of those reaction (elimination (E1 or E2) or subtitution (SN1 or SN2)? ...
-1
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0answers
46 views

I want to prepare copper(1) sulfide in lab which chemicals would be required and by which method? [closed]

I want to know a simple method to prepare copper(1) sulfide with least expensive chemicals and in short time. further, using cuprous chloride with which sulfide gives copper (1) sulfide is there any ...

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