15 votes
Accepted

Why isn't sodium hydrogen phthalate used instead of KHP?

For classical analytical problems you have to check at least 100 year old literature. It is easy in Google Scholar. Set the date limits to 1920s or 1950s whatever you wish to try. In older times, the ...
AChem's user avatar
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10 votes

Why do we have to use anhydrous AlCl3 in Gatterman-Koch Reaction?

Anhydrous $\ce{AlCl3}$ is used because it reacts violently with water details here and you then no longer have an aluminium compound that will react. $\ce{AlCl3}$-catalysed reactions occur because it ...
Waylander's user avatar
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7 votes
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TKN: Why are they called Missouri tablets?

As suggested in the comments, the predecessor of the method that uses "Missouri" tablets was developed at the University of Missouri (Columbia, Missouri, USA). I believe the first report was ...
Andrew's user avatar
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5 votes
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Reduction of conjugated ketone with lithium aluminium hydride

I'll take the opportunity to expand on the Comments and links I provided previously. The intermediate you proposed does not occur during the LiAlH4 reduction of the enol ethers of dihydroresorcinols ...
user55119's user avatar
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5 votes
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Salt used in Perkin Reaction

The base, as you pointed out is nearly always the salt of the acid corresponding to the annhydride. This is because the base which differs in structure will react with the given carbonyl compound and ...
Meghaj.B's user avatar
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4 votes
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Why does 3-hydroxy-butan-2-one give positive Tollens' test?

From the Wikipedia entry on Tollens 1 Tollens' reagent is a chemical reagent used to determine the presence of an aldehyde, aromatic aldehyde and alpha-hydroxy ketone functional groups The ...
Waylander's user avatar
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4 votes
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Labware to handle hot aqueous NaOH

Instead of glassware, you might have to think about metallic containers. A 1 M NaOH solution should not be that harsh for stainless steel for a short period of time. Imagine, in the chlor-alkali ...
AChem's user avatar
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4 votes
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How can one determine if all reagents will react in the reaction?

That is correct, the two numbered reagent and solvent pairs refer to two reactions, that will be done one after the other. There is an intermediate product that can be isolated, or at least identified....
Karl's user avatar
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3 votes
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Dihaloalkane reaction with sodamide/ammonia

You were correct up to this point, the strong base alcoholic KOH sets off elimination instead of substitution so you will not get an alcohol. Accordingly your products A (presumably propene) and B are ...
Oscar Lanzi's user avatar
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3 votes
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Major product in reaction of butan-2-one + selenium dioxide

To understand the major factor we have to consider the mechanism of the reaction first. The reaction you mentioned is popularly know as Riley oxidation. The mechanism is as follows: As you can ...
Nisarg Bhavsar's user avatar
3 votes
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Reaction of 1,2-diketones with periodic acid

Yes it does, under basic conditions to give two carboxylic acids, according to this paper by Bunton & Shiner J. Chem. Soc., 1960, 1593-1598 here Abstract of the paper: The oxygen atom of ...
Waylander's user avatar
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3 votes

Action of EtONa/EtOH on compound containing -CN group

My answer will be somewhat contradicting that of @Waylander, but I believe it's correct since I know where the question has come from and have solved it before. The first step with $\ce{KCN}$ ...
TRC's user avatar
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2 votes

Reagent notation: meaning of dash(-) and line(|) or slash(\) in reagents

The '|' in $\ce{Pd|BaSO4}$ implies that the reaction is taking place in the presence of $\ce{Pd}$ as a metal catalyst. This metal provides surface area for reaction to occur. Also '/' in $\ce{Cr2O3-...
PV.'s user avatar
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2 votes
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Action of EtONa/EtOH on compound containing -CN group

In the event that the phenethyl chloride is meant to be benzyl chloride then this is the solution I believe the question setter is looking for: A is phenylacetonitrile which is deprotonated by ...
Waylander's user avatar
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2 votes

Is hydronium an electrophile, nucleophile, both or neither?

Firstly, I would like to point out that, when we talk about electrophiles (E) and nucleophiles (Nu), we may be calling the entire molecule an electrophile or a nucleophile, but in reality we are ...
Miko's user avatar
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2 votes
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How tartaric acid gives Tollen's test?

Maxted[1] reported in 1926 that the reaction of tartaric acid with silver produces oxalic acid, formic acid, CO2 and water as products and that the stoichiometry is 6 moles of silver reduced per ...
Andrew's user avatar
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1 vote

Major product in reaction of butan-2-one + selenium dioxide

This is known as the Riley Oxidation. The Wikipedia entry states that ketones with two alpha methylene positions react more quickly at the least hindered site which references Riley's original paper1. ...
Waylander's user avatar
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1 vote

1000 mg/L alkalinity as CaCO3 standard preparation

The problem is the soloubility of calcium carbonate is very poor. It is 14 mg/l. So it is not possible to prepare a solution with 1 g/l, but instead you can use sodium carbonate, the soloubility 217 g/...
Nobby's user avatar
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1 vote
Accepted

Why don't we use silver hydroxide instead of Tollen's reagent for test of aldehydes?

Silver hydroxide does not exist. Hydroxides of alkalic metals form insoluble silver oxide: $$\ce{ 2 Ag+ + 2 OH- -> Ag2O + H2O}$$ Ammonia forms with silver ions the linear diammin complex, the ...
Poutnik's user avatar
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1 vote
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Wetting agent for H2O2 solution

Listerine/Total Care/Stain Remover/Anticavity Mouthwash (4 lines to name the product!) contains H2O2 and sodium lauryl sulfate (and 21.6% ethanol) in a purple plastic bottle. Both the ethanol and the ...
James Gaidis's user avatar
1 vote

Wetting agent for H2O2 solution

You might consider chlorhexidine gluconate. It is a cationic surfactant used as a skin cleanser and disinfectant prior to surgery, and is an ingredient in certain mouthwash products, so it must have ...
iad22agp's user avatar
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