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How will you prepare phosphine and explain the purification of phosphine ? |
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Answer» Solution :Phosphine is prepared by action of sodium HYDROXIDE with white phophorous in an inert atmosphere of carbon dioxide or hydrogen. `P_(4) + 3NaOH + 3H_(2) O rarr underset("sodium hypo phosphite")(3NaH_(2)PO_(2)) + underset("Phosphine")(PH_(3) UARR)` Phosphine is freed from phosphine dihydride `(P_(2)H_(4))` by passing through a freezing mixture. The dihydride condenses while phosphine does not. Phosphine can also prepared by the hydrolysis of metallic phosphides with water or dilute mineral acids. `{:(Ca_(3)P_(2) + 6H_(2)O,rarr,underset("Phosphine")(2PH_(3)uarr) + 3Ca(OH)_(2)),(AIP + 3HCI,rarr,underset("Phosphine")(PH_(3) uarr) + AlCl_(3)):}` Phosphine is prepared in PURE form by heating phosphorous acid. `underset("Phosphorous acid")(4H_(3)PO_(3)) overset(Delta)rarr underset("Ortho phosphoric acid")(3H_(3)PO_(4)) + underset("Phosphine")(PH_(3) uarr)` A pure sample of phosphine is prepared by heating phosphine IODIDE with caustic soda solution. `PH_(4)I + NaOH overset(Delta)rarr underset("Phosphine")(PH_(3) uarr) + NaI + H_(2)O` |
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