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preface to fifteenth edition

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PRACTICAL LABORATORY INFORMATION 11.119<br />

for the lather fac<strong>to</strong>r (the lather fac<strong>to</strong>r is that amount of standard soap solution required <strong>to</strong> produce<br />

a permanent lather in a 50-mL portion of distilled water). One milliliter of this solution after<br />

subtracting the lather fac<strong>to</strong>r is equivalent <strong>to</strong> 1mg of CaCO 3 .(b) Boutron-Boudet—dissolve<br />

100 g of pure castile soap in about 2500 mL of 56% ethyl alcohol and adjust so that 2.4 mL will<br />

give a permanent lather with 40 mL of a solution containing 0.59 g Ba(NO 3 ) 2 per liter of water;<br />

2.4 mL of this solution is equivalent <strong>to</strong> 22 French degrees or 220 parts per million of hardness<br />

(as CaCO 3 ) on a 40-mL sample of water.<br />

Sodium acetate, NaC2H3O 2· 3H2O:<br />

dissolve 1 part of the salt in 10 parts of water.<br />

Sodium acetate, acid: dissolve 100 g of sodiumacetate and 30 mL of glacial acetic acid in water<br />

and dilute <strong>to</strong> 1 liter.<br />

Sodium bismuthate (oxidation of manganese): heat 20 parts of NaOH nearly <strong>to</strong> redness in an<br />

iron or nickel crucible, and add slowly 10 parts of basic bismuth nitrate which has been previously<br />

dried. Add 2 parts of sodiumperoxide, and pour the brownish-yellow fused mass on an iron plate<br />

<strong>to</strong> cool. When cold break up in a mortar, extract with water, and collect on an asbes<strong>to</strong>s filter.<br />

Sodium carbonate, Na2CO393N: 159 g per liter; one part Na 2 CO 3 , or 2.7 parts of the crystalline<br />

Na2CO 3· 10H2O in 5 parts of water.<br />

Sodium chloride, NaCl90.5N: 29gper liter.<br />

Sodium chloroplatinite, Na 2 PtCl 4 : dissolve 1 part of the salt in 12 parts of water.<br />

Sodium cobaltinitrite, Na2Co(NO 2) 690.3N: dissolve 230 g of NaNO 2 in 500 mL of water, add<br />

160 mL of 6N acetic acid and 35 g of Co(NO 3) 2· 6H2O.<br />

Allow <strong>to</strong> stand one day, filter, and dilute<br />

the filtrate <strong>to</strong> a liter.<br />

Sodium hydrogen phosphate, Na2HPO 4· 12H2O90.5N: 60gliter.<br />

Sodium hydroxide, NaOH95N: 220 g per liter.<br />

Sodium hydroxide, alcoholic: dissolve 20 g of NaOH in alcohol and dilute <strong>to</strong> 1 liter with<br />

alcohol.<br />

Sodium hypobromite: dissolve 100 g of NaOH in 250 mL of water and add 25 mL of bromine.<br />

Sodium nitrate, NaNO390.5N: 43gper liter.<br />

Sodium nitroprusside (for sulfur detection): dissolve about 1g of sodiumnitroprusside in<br />

10 mL of water; as the solution deteriorates on standing, only freshly prepared solutions should<br />

be used. This compound is also called sodium nitroferricyanide and has the formula<br />

Na2Fe(NO)(CN) 5 · 2H2O.<br />

Sodium polysulfide, Na 2 S x : dissolve 480 g of Na2S · 9H2O in 500 mL of water, add 40 g of<br />

NaOH and 18 g of sulfur, stir mechanically and dilute <strong>to</strong> 1 liter with water.<br />

Sodium sulfate, Na2SO490.5N: 35gper liter.<br />

Sodium sulfide, Na 2 S: saturate NaOH solution with H 2 S, then add as much NaOH as was used<br />

in the original solution.<br />

Sodium sulfite,<br />

Na SO · 7H O90.5N: 63g<br />

2 3 2<br />

per liter.<br />

Sodium sulfite, acid (saturated): dissolve 600 g of NaHSO 3 in water and dilute <strong>to</strong> 1 liter; for the<br />

preparation of addition compounds with aldehydes and ke<strong>to</strong>nes: prepare a saturated solution of<br />

sodiumcarbonate in water and saturate with sulfur dioxide.<br />

Sodium tartrate, acid, NaHC 4 H 4 O 6 : dissolve 1 part of the salt in 10 parts of water.<br />

Sodium thiosulfate, Na2S2O 3· 5H2O:<br />

one part of the salt in 40 parts of water.<br />

Sonnenschein’s reagent (alkaloid detection): a nitric acid solution of ammonium molybdate is<br />

treated with phosphoric acid. The precipitate so produced is washed and boiled with aqua regia

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