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│Item │Standards and tests │
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│Assay │Not less than 97% (v/v) │
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│Description │Colourless, odourless gas │
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│Solubility │1 volume dissolves in 1.5 volumes of│
│ │water (20℃, 760 mm Hg) │
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│Flame test │A glowing splinter of wood in │
│ │contact with nitrous oxide bursts │
│ │into flame (distinction from │
│ │nitrogen). │
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│Pyrogallol test │Collect about 100 mL of the gas │
│ │under test in a 100-mL tube fitted │
│ │at the top with a stopcock. Open the│
│ │stopcock, and quickly add a freshly │
│ │prepared solution of 500 mg of │
│ │pyrogallol in 2 mL of water and a │
│ │freshly prepared solution of 12 g of│
│ │potassium hydroxide in 8 mL of │
│ │water. Immediately close the │
│ │stopcock and mix. The gas is not │
│ │absorbed and the solution does not │
│ │become brown(distinction from │
│ │oxygen). │
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│Carbon monoxide │Not more than 10 μL/L │
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│Nitric oxide and │Not more than 5 μL/L │
│nitrogen dioxide │ │
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│Halogens and hydrogen │Not more than 5 μL/L │
│sulfide │ │
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│Arsine and phosphine │Pass 10.0 L at a rate of 1.0 L/min │
│ │through a glass tube packed with │
│ │lead acetate TS on cotton wool and a│
│ │gas distribution head of the domed, │
│ │sintered type, of porosity 100, into│
│ │a tube of about 2.5 cm internal │
│ │diameter, containing 5 mL of Silver │
│ │DDC/Quinoline TS, the domed head │
│ │being almost in contact with the │
│ │bottom of the tube. The colour of │
│ │the Silver DDC/Quinoline TS is not │
│ │changed. │
│ │ │
│ │Silver DDC/Quinoline TS: Dissolve 50│
│ │mg of finely powdered silver nitrate│
│ │in 100 mL of quinoline and add 0.2 g│
│ │of silver diethyldithiocarbamate. │
│ │The reagent should be freshly │
│ │prepared. │
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