Question

$X$ reacts with aqueous $NaOH$ solution to form $Y$ and $H _{2}$ Aqueous solution of $Y$ is heated to $323-333 K$ and on passing $CO _{2}$ into it, $Na _{2} CO _{3}$ and $Z$ are formed. When $Z$ is heated to $1200^{\circ} C , Al _{2} O _{3}$ is formed. $X, Y$ and $Z$ respectively are

• A. $Al , AlCl _{3}, NaAlO _{2}$
• B. $Zn , Na _{2} ZnO _{2}, Al ( OH )_{3}$
• C. $Al , Al ( OH )_{3}, AlCl _{3}$
• D. $Al , NaAlO _{2}, Al ( OH )_{3}$

Answer 1

Answer: (D)

$\underset{(X)}{2 Al} +2 NaOH +2 H _{2} O \rightarrow \underset{(Y)}{2 NaAlO _{2}}+3 H _{2}$

$\underset{(Y)}{2 NaAlO _{2}}+ CO _{2}+3 H _{2} O \underset{(Z)}{\stackrel{\Delta}{\longrightarrow }} 2 Al ( OH )_{3}+ Na _{2} CO _{3}$

$\underset{(Z)}{2 Al ( OH )_{3}} \stackrel{1200^{\circ} C }{\longrightarrow } Al _{2} O _{3}+3 H _{2} O$