Given below are two statements : Statement I: Aluminium upon reaction with NaOH forms [Al(OH)_6]^ 3- ion. Statement II: The geometry of ICl_4^-, ClO_3^- and IBr_2^- is square planar, pyramidal and linear respectively. In the light of the above statements, choose the correct answer from the options given below :
D. Statement I is false but Statement II is true
Statement I: Aluminium reacts with aqueous sodium hydroxide to form sodium tetrahydroxoaluminate(III) and liberates hydrogen gas. The reaction is given by: 2Al + 2NaOH + 6H_2O 2Na^+[Al(OH)_4]^- + 3H_2 The complex ion formed is [Al(OH)_4]^-, not [Al(OH)_6]^ 3- . Thus, Statement I is false. Statement II: For ICl_4^-, the central iodine atom has 7 valence electrons + 1 (from negative charge) = 8 electrons. It forms 4 sigma bonds with Cl atoms and has 2 lone pairs. The hybridization is sp^3d^2 and the shape is square planar. For ClO_3^-, the central chlorine atom has 7 valence electrons + 1 = 8 electrons. It forms 3 sigma bonds with O atoms and has 1 lone pair. The hybridization is sp^3 and the shape is trigonal pyramidal. For IBr_2^-, the central iodine atom has 7 valence electrons + 1 = 8 electrons. It forms 2 sigma bonds with Br atoms and has 3 lone pairs. The hybridization is sp^3d and the shape is linear. Thus, Statement II is true. Therefore, Statement I is false but Statement II is true. Answer: Statement I is false but Statement II is true
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