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A certain salt X, gives the following results. (i) Its aqueous solution is alkaline to litmus. (ii) It swells up to a glassy material Y on strong heating (iii) When conc. H_2SO_4 is added to a hot solution of X, white crystal of an acid Z separates out. Write equations for all the above reactions and identify X, Y and Z.

Answer» <html><body><p></p>Solution : (i) The given salt is alkaline to litmus. Therefore, X is a salt of a <a href="https://interviewquestions.tuteehub.com/tag/strong-653928" style="font-weight:bold;" target="_blank" title="Click to know more about STRONG">STRONG</a> base and a weak acid. Also, when X is strongly heated, it swells 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> substance Y. Therefore, X <a href="https://interviewquestions.tuteehub.com/tag/must-2185568" style="font-weight:bold;" target="_blank" title="Click to know more about MUST">MUST</a> be borax. <br/> `underset"(X)"(Na_2B_4O_7). 10H_2O overset(H_2O) tounderset"(Strong base)"(2NaOH) + underset"(Weak acid)"(H_2B_4O_7)` <br/> (ii) When borax is heated, it loses <a href="https://interviewquestions.tuteehub.com/tag/water-1449333" style="font-weight:bold;" target="_blank" title="Click to know more about WATER">WATER</a> and swells to form sodium metaborate. When heating is continued, it solidifies to form a glassy material Y. Hence, Y must be a mixture of sodium metaborate and boric anhydride. <br/>`Na_2B_4O_7 . 10H_2O overset(Delta)to Na_2B_4O_7 + 10 H_2O` <br/> `Na_2B_4O_7 <a href="https://interviewquestions.tuteehub.com/tag/oversetdeltato-2905750" style="font-weight:bold;" target="_blank" title="Click to know more about OVERSETDELTATO">OVERSETDELTATO</a> ubrace(2NaBO_2+B_2O_3)_((Y))` <br/> (iii)When concentrated acid is added to borax, white crystals of orthoboric acid (Z) are formed.<br/> `Na_2B_4O_7. 10H_2O + H_2SO_4 to underset"(Z)"(4H_3BO_3) + 5H_2O + Na_2SO_4`</body></html>


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