In the leaching method bauxite ore is digested with a concentrated solution of NaOH that produces 'X' whne `CO_(2)` gas is passed through the aquesous solution of 'X' a hydrated compound 'Y' is precipited 'X' and 'Y' respectively are:

Options

A. `Na[AL(OH)_4 ] and AI_2 (CO_3 )_3 .xH_2 O`
B. `Al (OH )_3 and Al_2 O_3 .x H_2 O`
C. `NaAlO_2 and Al_2 (CO_3)_3 . X H_2 O`
D. ` Na [Al (OH)_4 )] nad Al_2 O_3 . X H_2 O`

Answer

D

Explanation

`underset( "alumina") (Al_2 O_3 (s) )+ 2Na OH (aq) +3H_2 O (l) `
` underset( 35-36 b a r )overset( 473 -523 K ) to underset( (X )) underset("sodium aluminate ") (2Na[Al(OH_4 ](aq))`
` 2Na [Al (OH)_4 (aq) +CO_2 (g) to `
` underset("(Y)") underset("hydrated alumina ") ( Al_2 O_3 .xH_2 O (s) + 2Na HCO_2 (aq) )`