Basic aqueous solution

Potassium (or sodium) nitrate (saturated 376.5 For neutral and basic aqueous solutions ... 

The tetrathiomolybdate ion [16550-92-0] (Fig. 2b), which has received great attention in the late 20th century, was first reported by BerzeHus in 1838. The simple preparation from molybdate in basic aqueous solution occurs in high yield according to ... 

Carbon steel is easily the most commonly used material in process plants despite its somewhat limited corrosion resistance. It is routinely used for most organic chemicals and neutral or basic aqueous solutions at moderate temperatures. It is also used routinely for the storage of concentrated sulfuric acid and caustic soda [up to 50 percent and 55°C (I30°F)]. Because of its availability, low cost, and ease of fabrication steel is frequently used in services with corrosion rates of 0.13 to 0.5 mm/y (5 to 20 mils/y), with added thickness (corrosion allowance) to assure the achievement of desired service life. Product quahty requirements must be considered in such cases. 

A total of 3 g (0.13 moles) of sodium hydride is added to a solution consisting of 10 g of 17 -hydroxy-5a-androstan-3-one (36 mmoles) in 200 ml of benzene and 10 ml of ethyl formate. The reaction mixture is allowed to stand under nitrogen for 3 days followed by dropwise addition of 10 ml of methanol to decompose the excess of sodium hydride. The solution is then diluted with 300 ml water and the layers are separated. The basic aqueous solution is extracted with ether to remove neutral material. The aqueous layer is acidified with 80 ml of 3 A hydrochloric acid and the hydroxymethylene steroid is extracted with benzene and ether. The combined organic extracts are washed with water and saturated sodium chloride solution and then dried over magnesium sulfate and concentrated. The residue, a reddish-yellow oil, crystallized from 10 ml of ether to yield 9.12 g (83%) of 17 -hydroxy-2-hydroxymethylene-5a-androstan-3-one mp 162-162.5°. Recrystallization from chloroform-ether gives an analytical sample mp 165-165.5° [a]o 53° (ethanol) 2 ° 252 mjj. (g 11,500), 307 m u (e 5,800). 

After an additional 2 hours stirring at room temperature, the reaction mixture was poured onto ice water. The basic aqueous solution was washed twice with ethyl acetate (20 ml) and acidified to pH 3 with 10% aqueous hydrochloric acid. 

Using the Brensted-Lowry model, write an equation to show why each of the following species produces a basic aqueous solution. 

Thus, solutions of carbonates are found to be basic. Aqueous solutions of carbon dioxide are, on the other hand, acidic. The reactions in this equilibrium are... 

B. Recovery of (-)-DAG. The basic aqueous solution (about 186 ml.) obtained after removal of the (-)-amine by ether extraction is placed in a 600-ml. beaker and cooled to 0-5° with an ice bath. The solution is stirred with a magnetic stirrer and carefully acidified with aqueous 2N hydrochloric acid at 0-5° to approximately pH 2 (Note 11). The precipitated (-)-DAG is filtered without delay (Note 12), washed with 20 ml. of ice water, and air dried to constant weight. The yield of recovered (-)-DAG is 20.0-20.9 g. (91 -94%, yield based on the amount ofthe salt used), m.p. 103° (decomp.), [a] —21.6° (c 2.28%, methanol) (Notes 13 and 14). 

Salts that contain the conjugate acids of weak bases produce acidic aqueous solutions so do salts that contain small, highly charged metal cations. Salts that contain the conjugate bases of weak acids produce basic aqueous solutions. 

The products of the reaction between bromide ions and permanganate ions, Mn04, in basic aqueous solution are solid manganese(IV) oxide, MnO>, and bromate ions. Balance the net ionic equation for the reaction. 

Sei f-Test 12.2B When iodide ions react with iodate ions in basic aqueous solution, triiodide ions, I,, are formed. Write the net ionic equation for the reaction. (Note that the same product is obtained in each half-reaction.)... 

Radical-mediated silyldesulfonylation of various vinyl and (a-fluoro)vinyl sulfones 21 with (TMSlsSiH (Reaction 25) provide access to vinyl and (a-fluoro)vinyl silanes 22. These reactions presumably occur via a radical addition of (TMSlsSi radical followed by /)-scission with the ejection of PhS02 radical. Hydrogen abstraction from (TMSlsSiH by PhS02 radical completes the cycle of these chain reactions. Such silyldesulfonylation provides a flexible alternative to the hydrosilylation of alkynes with (TMSlsSiH (see below). On oxidative treatment with hydrogen peroxide in basic aqueous solution, compound 22 undergoes Pd-catalyzed cross-couplings with aryl halides. 

Finally, phosphorus porphyrins, such as some of those detailed in Sect. 2.3.1 have attracted attention in organic chemistry for their unique photochemical properties. Aida reported that basic aqueous solutions of benzonitrile in the presence of 59a undergo under irradiation (A>420 nm) a clean transformation... 

C19-0010. Balance this reaction in basic aqueous solution MnOq -b Cd Mn02 + Cd (OH)2 ... 

C19-0014. The mercury battery, use of which is being discontinued because of the toxicity of mercury, contains HgO and Zn in contact with basic aqueous solution. The redox products are Hg and ZnO. Determine the oxidation and reduction half-reactions and the overall reaction for these batteries. 

C21-0070. In basic aqueous solution, A1 acts as a strong reducing agent, being oxidized to AIO2. Balance this half-reaction, and determine balanced net reactions for A1 reduction of the following (a) NO3 to NH3 (b) H2 O to H2 and (c) Sn03 to Sn. 

Stable in neutral to basic aqueous solution Unstable in acidic aqueous solution Flucarbazone-sodium is a post-emergent grass herbicide for use in winter wheat and spring wheat, including... 

C 2.41 X 10 mm Hg at 22.0°C 1.8mgL in water at 25°C Soluble in polar organic solvents Unstable in acidic, neutral and basic aqueous solutions Flumioxazin provides pre-emergence control of susceptible weeds in crops. Flumioxazin may also be used as part of an early preplant burn-down program in various crops... 

Stable in neutral aqueous solution, less stable in basic aqueous solution... 

Trinexapac-ethyl decomposes to its acid form in acidic or basic aqueous solution and is light sensitive. Samples should be analyzed immediately or stored in the dark until analysis... 

Oxime carbamates have high polarity and solubility in water and are relatively chemically and thermally unstable. They are relatively stable in weakly acidic to neutral media (pH 4-6) but unstable in strongly acidic and basic media. Rapid hydrolysis occurs in strongly basic aqueous solutions (pH > 9) to form the parent oxime/alcohol and methylamine, which is enhanced at elevated temperature. Additionally, oxime carbamates are, generally, stable in most organic solvents and readily soluble in acetone, methanol, acetonitrile, and ethyl acetate, with the exception of aliphatic hydrocarbons. Furthermore, most oxime carbamates contain an active -alkyl (methyl) moiety that can be easily oxidized to form the corresponding sulfoxide or sulfone metabolites. 

Stable in acidic, neutral and basic aqueous solutions Pale yellowish solid, faint characteristic odor Flash point 119°C (Pensky-Martens closed tester) Pyriproxyfen is an insect growth regulator which acts both as an ovacide and as an inhibitor of development (juvenile hormone mimic) against white flies, scale, and psylla. The specificity of pyriproxyfen, and its low mammalian toxicity, allow for some variation in application timing. For example, the lack of toxicity to bees allows pyriproxyfen to be applied during bloom on apple trees, and its low mammalian toxicity allows for a very short pre-harvest interval on citrus The residue definition is for pyriproxyfen alone... 

To study the factors leading to the unusual hydrolytic stability of polydimethacrylamides, we synthesized poly[N-(4-sulfophenyl)di-methacrylamide] (PSPDM) (IV). PSPDf s water soluble, in contrast to the previously studied polymers. The hydrolytic stability of PSPDM was studied in acidic, neutral, and basic aqueous solutions at 90 C and above. The results of these experiments will be described. 

Spectral data of these alkaloids are presented in the review works (4,8) but do not include data for bicucullinidine (110), which was discovered in 1981 (113-116). In the IR spectra of these compounds the carbonyl region generally consists of three bands. The first one is placed at 1675-1670 cm-1 and the latter two around 1625-1590 cm-1. The amino acid nature of these compounds is demonstrated by the presence of an NH band (2350 cm-1) found in the IR spectrum of bicucullinine (108) (117), as well as by the solvent-dependent position of the N(CH3)2 group in the H-NMR spectra. For instance, in the spectrum of bicucullinine (108) run in basic aqueous solution it can be found at <52.08 (118), in DMSO-d6 at <52.69 (113,116), and in CFjCOOD at <53.13 (117,119). Moreover, in H-NMR spectra the influence of the C-l carbonyl group on the chemical shift of H-8 can be observed. This proton falls in its deshielding zone and is shifted downfield around 1 ppm compared to the absorption of H-8 in spectra of monoketo acids. 

The reaction is usually carried out in basic aqueous solution from which Mn02 precipitates as the oxidation takes place. 

Phenylene-bridged periodic mesoporous organosilicas, with both amorphous and crystal-like walls, (referred to in the following as AW-Ph-HMM and CW-Ph-HMM, respectively) were synthesized and characterized as previously reported [6,7]. BTEB was used as a precursor for both solids the surfactant was Brij-76 (Ci8H37(OCH2CH2)nOH) in acidic media for AW-Ph-HMM and octadecyl-trimethylammonium bromide(ODTMA) in basic media for CW-Ph-HMM. A purely siliceous MCM-41 sample was also synthesised, the first step being the solution of octadecyltrimethylammonium bromide in a basic aqueous solution (NH3), kept a 333 K. Tetraethyl orthosilicate (TEOS) was then added in all cases dropwise, and the mixture stirred for 24h at room temperature (H20 34.2 g/ NH3 (15%) 8.52 g/ ODTMA 0.73 g TEOS 3.24 g). After further 24 hours in hydrothermal conditions at 368 K, the sample... 

Organolithium reagents have also been employed for the synthesis of novel bis(alkynyl)mercury derivatives. These include Hg(C=CCF3)263 and 46-48,64 which have been synthesized along with the bis(alkynyl)aurate analogs. Bis(alkynyl)mercury species such as 49 can also be obtained by reaction of monosubstituted alkynes with K2[Hgl4] in basic aqueous solutions.6 ... 

When the oxide reacts in basic aqueous solution, the reaction leads to a hydroxo complex and can be shown as follows ... 

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