Acids zinc with hydrochloric acid

Hydrogen can be prepared by the reaction of water or dilute acids on electropositive metals such as the alkali metals, alkaline earth metals, the metals of Groups 3, 4 and the lanthanoids. The reaction can be explosively violent. Convenient laboratory methods employ sodium amalgam or calcium with water, or zinc with hydrochloric acid. The reaction of aluminium or ferrosilicon with aqueous sodium hydroxide has also been used. For small-scale preparations the hydrolysis of metal hydrides is convenient, and this generates twice the amount of hydrogen as contained in the hydride, e.g. ... 

A student reacts a sample of zinc with hydrochloric acid. He collects the gas as it bubbles through water. How will this student need to correct his measurements Explain your answer. 

The concept of moles is extremely useful for determining how much of one substance you need to complete a chemical reaction with another substance. For example, the balanced equation for the reaction of zinc with hydrochloric acid is given below. Note I m not suggesting you actually try this reaction. It s a bit violent, and it s always a risk doing such a reaction with a strong acid. 

Write the equation fot the reaction of zinc with hydrochloric acid. Would you expect zinc to di.ssoIve in a concentrated solution of sodium hydroxide If so, write the equation for this reaction. 

This dependence of the interpretation of a phenomenon on the particular properties that are measured is true of much scientific knowledge. Take for example the reaction of zinc with hydrochloric acid If our measurements were limited to a chemical analysis, we would consider the reaction as due to a greater chemical affinity of chlorine for zinc than for hydrogen. However, if the reaction takes place in a primary cell, the resulting electromotive force shows that electrical forces are involved. 

This reaction was initially reported by Fischer in 1875. It is a synthesis of phenylhydrazine involving the diazotization of aniline, the reduction of the resulting diazonium salt with an excess amount of sodium sulfite, and the hydrolysis of phenylhydrazine sulfonic acid salt with hydrochloric acid. In addition, the diazonium salt can also be reduced by zinc dust in acetic acid. This process has become a standard industrial method for the production of arylhydrazines. 

The reaction of zinc with hydrochloric acid to produce bubbles of hydrogen gas. 

When the desired product of a chemical reaction is a gas, the gas is often collected by the displacement of water. For example, suppose we use the reaction of zinc with hydrochloric acid as a source of hydrogen gas ... 

This procedure afforded us a safe and scalable method for the ring closure of 17 to 18. The product crystallized from the reaction mixture after quenching the excess zinc with hydrochloric acid and subsequent addition of water. This crystallization however was not selective the isolated product 18 contained about 8% of 16 and 1.5% of 15, inq)urities which were removed in tibe next step. 

Clemmensen reduction Aldehydes and ketones may generally be reduced to the corresponding hydrocarbons by healing with amalgamated zinc and hydrochloric acid. 

Allyl Chloride. Comparatively poor yields are obtained by the zinc chloride - hydrochloric acid method, but the following procedure, which employs cuprous chloride as a catalyst, gives a yield of over 90 per cent. Place 100 ml. of allyl alcohol (Section 111,140), 150 ml. of concentrated hydrochloric acid and 2 g. of freshly prepared cuprous chloride (Section II,50,i one tenth scale) in a 750 ml. round-bottomed flask equipped with a reflux condenser. Cool the flask in ice and add 50 ml. of concen trated sulphuric acid dropwise through the condenser with frequent shaking of the flask. A little hydrogen chloride may be evolved towards the end of the reaction. Allow the turbid liquid to stand for 30 minutes in order to complete the separation of the allyl chloride. Remove the upper layer, wash it with twice its volume of water, and dry over anhydrous calcium chloride. Distil the allyl chloride passes over at 46-47°. 

An important general method of preparing indoles, known as the Fischer Indole synthesis, consists in heating the phenylhydrazone of an aldehyde, ketone or keto-acld in the presence of a catalyst such as zinc chloride, hydrochloric acid or glacial acetic acid. Thus acrtophenone phenylhydrazone (I) gives 2-phenyllndole (I V). The synthesis involves an intramolecular condensation with the elimination of ammonia. The following is a plausible mechanism of the reaction ... 

The order of reactivity with acid is HI > HBi > HCl. Reaction with hydrochloric acid [7647-01-0] to form isopropyl chloride [75-29-6] is faciUtated by a zinc chloride catalyst. 

Arsenic vapor [12187-88-5] As, does not combine direcdy with hydrogen to form hydrides. However, arsine (arsenic hydride) [7784-42-17, AsH, a highly poisonous gas, forms if an intermetaUic compound such as AlAs is hydrolyzed or treated with HQ. Arsine may also be formed when arsenic compounds are reduced using zinc in hydrochloric acid. Heating to 250°C decomposes arsine into its elements. 

Secondary aisines, which can be synthesized by methods analogous to those used for piimaiy arsines, are obtained in good yields by the reduction of arsinic acids (44) or haloarsines (45) with amalgamated zinc and hydrochloric acid. They can also be prepared by the alkylation of primary arsenides (46) ... 

Ethyl Chloride. Previously a significant use for industrial ethanol was the synthesis of ethyl chloride [75-00-3] for use as an intermediate in producing tetraethyllead, an antiknock gasoline additive. Ethanol is converted to ethyl chloride by reaction with hydrochloric acid in the presence of aluminum or zinc chlorides. However, since about 1960, routes based on the direct addition of hydrochloric acid to ethylene or ethane have become more competitive (374,375). 

When saccharin is treated with diethyl phosphorothiolothionate, the 3-ethylmercapto compound is obtained, rather than the expected organophosphorus compound (77 ACS(B)460). Treatment of saccharin with phosphorus pentoxide and amines gives 3-(substituted-amino)-1,2-benzisothiazole 1,1-dioxides, via an intermediate phosphate (81ZN(B)1640). Reduction of saccharin with zinc and hydrochloric acid gives 2,3-dihydro-l,2-benzisothiazole 1,1-dioxide, the method being used to estimate saccharin in foodstuffs (75MI41701). 

By a modified Bischler-Napieralsky reaction, 6 -nitrophenylaceto-jS-3 4-methylenedioxyphenylethylamide, resulting from the condensation of -3 4-methylenedioxyphenylethylamine with 2-nitrophenylacetyl chloride, was converted into 6 nitro-l-benzyl-6 7-methylenedioxy-3 4-dihydroisoquinoline. The methiodide of the latter was reduced with zinc and hydrochloric acid to 6 -amino-l-benzyl-2-methyl-6 7-methylenedioxy-1 2 3 4-tetrahydro/soquinoline dihydrochloride, which by the Pschorr ring-closure reaction, produced dZ-roemerine (IV, p. 317), m.p. 85-7°. By treatment in succession with d- and Z-tartaric acids, the dZ-base was resolved into Z- and tZ-forms. Synthetic Z-roemerine is dimorphic, m.p. 85-7° and 102°, and has [aju — 79-9° (EtOH), these constants being in good agreement with those of the natural base. 

Meroquinenine, CgHjjOaN (meroquinene), formed by the oxidation of all four alkaloids and of cinchoninone or quininone and by the hydrolysis of quinenine or cinchenine (p. 489), crystallises from methyl alcohol in needles, m.p. 223-4° (dee.), [ajp -f- 27-5° (H2O). It gives a nitrosoamine, m.p. 67°, and a monoacetyl derivative, m.p. 110°, and can be esterified the ethyl ester hydrochloride has m.p. 165°. When oxidised by chromic acid it yields formic and cincboloiponic acids. On reduction with zinc dust and hydriodic acid, it adds on two atoms of hydrogen forming cincholoipon, CgH jOaN, and when heated with hydrochloric acid at 250-60° gives 3-ethyl-4-methylpyridine ()3-collidine). 

Zinc powder (32.8 g,0.5 moles) is washed successively with hydrochloric acid (3%, 4 X 25 ml), distilled water (4 x 30 ml), aqueous copper sulfate (2%, 2 X 50 ml), distilled water (4 x 30 ml), absolute ethanol (4 x 30 ml) and absolute ether (5 x 25 ml). The washings are performed conveniently by stirring a mixture of the zinc powder and each wash solution with a porcelain spatula in an open beaker and then decanting the supernatant liquid. The couple is finally transferred to a Buchner funnel, washed with additional anhydrous ether, and then vacuum-dried in a round-bottom flask. 

Benzoin yields hydrobenzoin on reduction with sodium amalgam, and clesoxybenzoin, C H,CO.CHj.C,Hj, when reduced with zinc and hydrochloric acid. 

The use of primary amines instead of ammonia affords l,2-dialkyl-/l -pyrrolines or l,2-dialkyl-/l -piperideines. Amino ketones with a primary amino group are intermediates in the reduction of y-nitropropylalkyl ketones (14,15) or S-nitrobutylalkyl ketones (16-18) by catalytic hydrogenation over Raney nickel or with zinc and hydrochloric acid (Scheme 1). 

The dimer of 1-methyl- -pyrroline (39) was obtained by reduction of N-methylpyrrole with zinc and hydrochloric acid (132) and, together with the trimer, by mercuric acetate dehydrogenation of N-methylpyrrolidine (131). J -Pyrroline-N-oxides form dimers in a similar manner (302). Treatment of 1,2-dimethyl-zl -piperideine with formaldehyde, producing l-methyl-3-acetylpiperidine (603), serves as an example of a mixed aldol reaction (Scheme 18). 

The reduction of 2-methyl-1,2,3,4-tetrahydro-y-carboline (92) with zinc and hydrochloric acid in the presence of mercuric chloride gives the indolenine derivative, 2-methyl-l,2,3,4,4a,9b-hexahydro-y-carbo-line (93). A related compound, 4,9b-diethyl-2-methyl-l,2,3,4,4a,9b-hexahydro-y-carboline (96), was obtained by catalytic hydrogenation of 95, which was prepared by Fischer ring closure of the phenyl-hydrazone 94. The stereochemistry of the B/C ring junction in these... 

The reaction of 3-morpholino-l,2,4-benzotiiazine 4-oxide 38 with zinc in hydrochloric acid afforded 3-morpholino-l,2,4-benzotriazine 39 (78USP4091098). 

Starting with cuminal, nitro-cuminal was prepared, the nitro group entering the para position, meta to the aldehyde group. This compound - when treated with phosphorus pentachloride was converted into nitro-cymyline chloride, which on reduction with zinc and hydrochloric acid... 

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