Sodium dihydrogen phosphite

EXAMPLE 6.18. What are the formulas for the dihydrogen phosphite ion and sodium dihydrogen phosphite ... 

Phosphorus acid is a moderately strong dibasic acid. It reacts with alkalies forming acid phosphites and normal phosphites. Thus, reaction with sodium hydroxide gives sodium dihydrogen phosphite and disodium hydrogen phosphite, but not sodium phosphate, Na3P04. 

Calculate the pH of (a) a 0.257 M aqueous sodium hydrogen oxalate (NajHOOCCOJ) solution (b) a 0.459 m sodium dihydrogen phosphite, NaH2P03, solution. 

Sodium dihydrogen phosphite, NaH2P03,2 H20, crystallizes when a solution of equimolecular proportions of phosphorous acid and sodium hydroxide is cooled to —23° C. The heat of formation of the anhydrous salt from the elements is 333 8 Cal.,8 and from the acid and sodium hydroxide in solution 14 83 Cal.10 The heat of hydration of the hydrate is 6 05 Cal. 

When anhydrous sodium dihydrogen phosphite is heated at 160° C. it is converted into disodium dihydrogen pyrophosphite, Na2H2P205. It forms microscopic crystals, reconverted by heating in solution into the parent substance. The heat of formation from the elements is 599 Cal.11... 

Name the following acids (a) H3PO3, (b) HCIO, and (c) HNO2. Write formulas for the following compounds (a) sulfuric acid and (b) sodium dihydrogen phosphite... 

Amino-l-nitro-l,2,4-triazole (581), obtained by nitration of 5-amino-triazole with acetyl nitrate, rearranges, on heating, to the nitramino-triazole (582). ° The combined action of sodium hydroxide, potassium iodide, tri-ethylamine, and sodium dihydrogen phosphite on the chloro-nitro-triazole (583) results in a mixture of the rearranged triazole (584), 3-chloro-l,2,4-triazole, and the coupled product (585). The stable betaine (586) has been prepared by treatment of 4-phenyl-1,2,4-triazole with phenacyl bromide, followed by tri-ethylamine. The meso-ionic triazolium thiolate (537 X = S) reacts with chlorine to form the dichloride (587 X = SCU), which has been converted into the betaine (588) by the action of diethyl bromomalonate in the presence of triethylamine. ... 

Colloidal palladium oxidises solutions of sodium dihydrogen hypo-phosphite to phosphite and phosphate in the same manner as the electrolytically deposited metal and palladium black (see p. 188), but the activity of the colloidal metal is greater. 

Palladium black catalvtically assists the oxidation of sodium dihydrogen hypophosphite solution to sodium phosphite, thus ... 

Trisodium phosphate Disodium hydrogen phosphate Monosodium dihydrogen phosphate Disodium phosphite or disodium phosphonate Sodium hydrogen phosphite or sodium hydrogen phosphonate Sodium bisidfate or sodium hydrogen sulfate Sodium bicarbonate or sodium hydrogen carbonate... 

What is the oxidation number of phosphorus in sodium phosphite, Na3P03 In the dihydrogen phosphate ion ... 

Of the various methods for preparing disodium dihydrogen hypophosphate, the one depending upon the oxidation of red phosphorus with sodium chlorite seems to be the best, considering both the yield and the simplicity of the procedure. In this reaction, phosphites and orthophosphates... 

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