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Aluminium trifluoride is insoluble in anhydrous HF but dissolves on addition of NaF.Aluminium trifluoride precipitates out of theresultingsolution when gaseousBF_(3) is bubbled through. Give reasons.

Answer» <html><body><p></p><a href="https://interviewquestions.tuteehub.com/tag/solution-25781" style="font-weight:bold;" target="_blank" title="Click to know more about SOLUTION">SOLUTION</a> :(i) Anhydrous `HF` is a covalent compoundand is strongly `H`-bonded. Therefore , it does not give `F^(-)` ions and hence `AlF_(3)` does notdissolve in `HF`. In contrast,`<a href="https://interviewquestions.tuteehub.com/tag/naf-572511" style="font-weight:bold;" target="_blank" title="Click to know more about NAF">NAF</a>`beingan ionic compound contains `F^(-)`ions andhence combineswith `AlF_(3)`to <a href="https://interviewquestions.tuteehub.com/tag/form-996208" style="font-weight:bold;" target="_blank" title="Click to know more about FORM">FORM</a> the soluble complex. <br/> `3NaF + AlF_(3) rarr <a href="https://interviewquestions.tuteehub.com/tag/underset-3243992" style="font-weight:bold;" target="_blank" title="Click to know more about UNDERSET">UNDERSET</a>((" soluble complex "))underset(" Sod. hetrafluoroborate (III) ")(3Na [BF_(4)]) + AlF_(3) (s)` <br/> (ii) Because of smaller size and higher electronegativity, has high <a href="https://interviewquestions.tuteehub.com/tag/much-2164829" style="font-weight:bold;" target="_blank" title="Click to know more about MUCH">MUCH</a> higher tendency to form complexes than Al, therefore when `BF_(3)` is added to the above solution. `AlF_(3)` gets precipitated. <br/></body></html>


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