JEE Main & Advanced Sample Paper JEE Main Sample Paper-5

  • question_answer
    In the extraction of aluminium, Process X applied for red bauxite to remove iron oxide (main impurity). Process Y (Serpech's process) Applied for white bauxite to remove Z (main impurity), then Process X and impurity Z are

    A)  X = Serpech's process and\[Z=F{{e}_{2}}{{O}_{3}}\]             

    B)  X = Bayer's process and \[Z=FeO\]

    C)  X = Hall and Heroullt's process and\[Z=Si{{O}_{2}}\]       

    D)  X = Bayer's process and \[Z=Si{{O}_{2}}\]

    Correct Answer: D

    Solution :

     Idea Problem includes the concept of purification techniques used in purification of aluminium such as Bayer's process and Serpech's process. According to Bayer's process, \[A{{l}_{2}}{{O}_{3}}\cdot 2{{H}_{2}}O+2NaOH\xrightarrow[{}]{{}}\underset{\begin{smallmatrix}  \text{Sodium}\,\text{meta} \\  \text{aluminate} \end{smallmatrix}}{\mathop{2NaAl{{O}_{2}}}}\,+3{{H}_{2}}O\]\[NaAl{{O}_{2}}+2{{H}_{2}}O\xrightarrow[{}]{{}}NaOH+\underset{\text{Precipitate}}{\mathop{Al{{(OH)}_{3}}}}\,\] The precipitate is washed and dried. Solution of NaOH is used again. TEST Edge In JEE Main, similar problem including purification technique used in purification of Ti, Zr, Ni etc., are also asked. Students are advised to go through study of purification techniques such as Van arkel method, Mond's process etc.


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