= Solution
\b[The three preparations use different chemistry: <diethyl ether> from <ethanol> by acid-catalysed dehydration, <carbon disulfide> by combination of <carbon> and <sulfur>, and <chloroform> by chlorination and cleavage of a suitable organic starting material.] “Ether” here means <diethyl ether>, not every member of the modern ether class; “bisulphide of carbon” means <carbon disulfide>.
For <diethyl ether>, heating <ethanol> with a suitable proportion of <sulfuric acid> favours intermolecular dehydration:
$$
\boxed{2\mathrm C_2\mathrm H_5\mathrm{OH}\longrightarrow\mathrm C_2\mathrm H_5\mathrm O\mathrm C_2\mathrm H_5+\mathrm H_2\mathrm O.}
$$
The historical explanation invokes formation of <ethyl hydrogen sulfate> and its reaction with a further ethanol molecule, regenerating sulfuric acid. The acid therefore need not be consumed stoichiometrically in the overall balance. The modern mechanism treats a protonated alcohol or related activated species as the substrate for attack by another ethanol molecule.<Organic Chemistry by John McMurry/18.2 Preparing Ethers>[Opening paragraph and reaction mechanism: sulfuric-acid-catalysed formation of symmetrical ethers from primary alcohols]{ref} Conditions matter: excessive heating favours formation of <Ethylene> rather than ether, and strongly oxidizing conditions can give additional products. Condensation of the volatile product, removal of acidic and water-soluble impurities, drying and redistillation separate production from purification. A cold receiver is appropriate to the volatile ether; an open flame near the escaping vapour would be incompatible with its ready flammability.
For <carbon disulfide>, sulfur vapour is brought into contact with sufficiently hot <charcoal> in a retort:
$$
\boxed{\mathrm C+2\mathrm S\longrightarrow\mathrm{CS}_2.}
$$
Here $\mathrm S$ records sulfur atoms in the balance, not a claim that the sulfur vapour has only monatomic molecules. The outgoing vapours are cooled and the liquid separated from excess sulfur and other impurities, then purified by distillation. The high-temperature reaction zone and the cooled collecting region have different functions. <Carbon disulfide> is a volatile, highly flammable solvent; its historical use does not establish harmlessness.<Carbon disulfide in the NIOSH Pocket Guide>[Physical Description, flammability and Symptoms]{ref}
For <chloroform>, a historically important route uses <ethanol> with a slurry containing <bleaching powder>. Oxidation first supplies <acetaldehyde>; further chlorination gives <chloral>, which alkali cleaves to <chloroform> and <formate>. An illustrative final step with <calcium hydroxide> is
$$
\boxed{2\mathrm{CCl}_3\mathrm{CHO}+\mathrm{Ca(OH)}_2\longrightarrow2\mathrm{CHCl}_3+\mathrm{Ca(HCOO)}_2.}
$$
The bleaching material supplies oxidizing and chlorinating capacity, while the alkaline conditions permit cleavage. It is misleading to describe the entire operation as one simple substitution directly replacing three hydrogens of intact ethanol. It is also unnecessary to pretend that commercial <bleaching powder> has a single invariant molecular composition.
<Acetone> supplies an alternative methyl-carbonyl starting material for the same broad haloform chemistry. In ionic notation a clean idealized balance is
$$
\mathrm{CH}_3\mathrm{COCH}_3+3\mathrm{OCl}^-\longrightarrow\mathrm{CHCl}_3+\mathrm{CH}_3\mathrm{COO}^-+2\mathrm{OH}^-.
$$
The volatile product is condensed with water-containing material; a chloroform-rich phase is separated, washed appropriately, dried and redistilled. Identity and purity require more than observing a dense lower layer. These operations describe preparation chemistry rather than a specified pharmacopoeial recipe or a claim of suitability for anaesthesia. The historical anaesthetic importance of <chloroform> does not remove its toxic effects.<Chloroform: toxicological overview by UKHSA>[Acute and delayed toxicity]{ref}
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