Zinc reaction with hydrochloric

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. 

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). 

As mentioned earlier, direct thermal dissociation of water requires temperatures above approximately 2500 K. Since there are not yet technical solutions to the materials problems, the possibility of splitting water instead, by various reaction sequences, has been probed. Historically, the reaction of reactive metals and reactive metal hydrides with water or acid was the standard way of producing pure hydrogen in small quantities. These reactions involved sodium metal with water to form hydrogen or zinc metal with hydrochloric acid or calcium hydride with water. All these... 

Figure 8.5 Reaction of Zinc Metal with Hydrochloric Acid...

Derivation Condensation of benzaldehyde with N,N-d m ct hy I an i I i n c, oxidation of the phenylmeth-ane product, and reaction with hydrochloric acid. It may be formed as a double salt of zinc chloride. 

When small quantities of elemental hydrogen gas are needed for laboratory work, the hydrogen is often generated by chemical reaction of a metal with acid. For example, zinc reacts with hydrochloric acid, releasing gaseous elemental hydrogen ... 

You might be asking yourself why it is convenient to define a new function H. To answer that question, recall from Equation 5.5 that AE involves not only the heat q added to or removed from the system but also the work w done by or on the system. Most commonly, the only kind of work produced by chemical or physical changes open to the atmosphere is the mechanical work associated with a change in volume. For example, when the reaction of zinc metal with hydrochloric acid solution. 

Reaction of zinc (Zn) with hydrochloric acid to produce hydrogen gas a reaction that is siower than the decomposition of ammonium nitrate. 

Write the molecular equation and the net ionic equation for the reaction of zinc sulfide with hydrochloric acid. 

Now consider a chemical system—for example, the reaction of zinc metal with hydrochloric add. The reaction is... 

Reaction of zinc metal with hydrochloric acid at constant pressure... 

A FIGURE 1-3 A chemical property of zinc and gold reaction with hydrochloric acid... 

Aliphatic hydrocarbons can be prepared by the reduction of the readily accessible ketones with amalgamated zinc and concentrated hydrochloric acid (Clemmensen method of reduction). This procedure is particularly valuable for the prep>aration of hydrocarbons wdth an odd number of carbon atoms where the Wurtz reaction cannot be applied with the higher hydrocarbons some secondary alcohol is produced, which must be removed by repeated distillation from sodium. 

Clemmensen reaction is the reduction of carbonyl compounds with amalgamated zinc and concentrated 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. ... 

Synthesis of the remaining half of the molecule starts with the formation of the monomethyl ether (9) from orcinol (8). The carbon atom that is to serve as the bridge is introduced as an aldehyde by formylation with zinc cyanide and hydrochloric acid (10). The phenol is then protected as the acetate. Successive oxidation and treatment with thionyl chloride affords the protected acid chloride (11). Acylation of the free phenol group in 7 by means of 11 affords the ester, 12. The ester is then rearranged by an ortho-Fries reaction (catalyzed by either titanium... 

Reactions with aqueous solutions. Uniform dissolution or corrosion of metals in acid, alkaline or neutral solutions (e.g. dissolution of zinc in hydrochloric acid or in caustic soda solution general corrosion of zinc in water or during atmospheric exposure). Reactions with non-aqueous solution (e.g. dissolution of copper in a solution of ammonium acetate and bromine in alcohol). 

When an alkali metal contacts water, metal atoms donate electrons to water molecules, producing hydrogen gas and a solution of the metal cation (for example, Na ). When a metal such as Ca, Zn, or Fe is treated with a strong aqueous acid, hydronium ions in the acid solution accept electrons from metal atoms, creating cations that then dissolve. We describe these redox reactions in Chapter 4. Zinc metal, for example, reacts with hydrochloric... 

There are a number of variations of the Friedel-Crafts reactions that are useful in synthesis. The introduction of chloromethyl substituents is brought about by reaction with formaldehyde in concentrated hydrochloric acid and halide salts, especially zinc chloride.62 The reaction proceeds with benzene and activated derivatives. The reactive electrophile is probably the chloromethylium ion. 

The neutralization values were influenced by reduction with strong reducing agents, lithium aluminum hydride, sodium borohydride, and amalgamated zinc plus hydrochloric acid (35, 46). For the most part, the consumption of NajCOj and of NaOEt decreased in equivalent amounts. This is further confirmation of the assumption that lactones of the fluorescein type or of the lactol type are present. The reaction with sodium ethoxide was shown to be no true neutralization, that is, exchange of H+for Na+, at all, but an addition reaction w ith the formation of the sodium salt of a semi-acetal or ketal ... 

Zinc dust is frequently covered with a thin layer of zinc oxide which deactivates its surface and causes induction periods in reactions with compounds. This disadvantage can be removed by a proper activation of zinc dust immediately prior to use. Such an activation can be achieved by a 3-4-minute contact with very dilute (0.5-2%) hydrochloric acid followed by washing with water, ethanol, acetone and ether [/55]. Similar activation is carried out in situ by a small amount of anhydrous zinc chloride [156 or zinc bromide [157 in alcohol, ether or tetrahydrofuran. Another way of activating zinc dust is by its conversion to a zinc-copper couple by stirring it (180g) with a solution of 1 g of copper sulfate pentahydrate in 35 ml of water [/55]. 

The prominent role of alkyl halides in formation of carbon-carbon bonds by nucleophilic substitution was evident in Chapter 1. The most common precursors for alkyl halides are the corresponding alcohols, and a variety of procedures have been developed for this transformation. The choice of an appropriate reagent is usually dictated by the sensitivity of the alcohol and any other functional groups present in the molecule. Unsubstituted primary alcohols can be converted to bromides with hot concentrated hydrobromic acid.4 Alkyl chlorides can be prepared by reaction of primary alcohols with hydrochloric acid-zinc chloride.5 These reactions proceed by an SN2 mechanism, and elimination and rearrangements are not a problem for primary alcohols. Reactions with tertiary alcohols proceed by an SN1 mechanism so these reactions are preparatively useful only when the carbocation intermediate is unlikely to give rise to rearranged product.6 Because of the harsh conditions, these procedures are only applicable to very acid-stable molecules. 

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