MolSynapsequestion bank

MolSynapse / Question bank / p-Block Elements: Groups 13 and 14 / Aluminium compounds and alums

JEE Main levelSingle correct optionDifficulty 2 of 3pb024

In the Bayer process, carbon dioxide is passed through a solution of sodium aluminate to

Aremove iron oxide as iron carbonate
Bprecipitate hydrated alumina, $Al (OH) X_{3}$ , by lowering the pH
Coxidise sodium aluminate to $Al X_{2} O X_{3}$ directly at 300 K
Dreduce aluminate to aluminium

Answer: B

Bauxite is digested in conc. NaOH to give

Na [Al (OH) X_{4}]

, leaving

Fe X_{2} O X_{3}

undissolved. Passing

CO X_{2}

neutralises alkali:

2 Na [Al (OH) X_{4}] + CO X_{2} 2 Al (OH) X_{3} + Na X_{2} CO X_{3} + H X_{2} O

, which precipitates

Al (OH) X_{3}

; it is then heated to give pure alumina.

Practice p-Block Elements: Groups 13 and 14 More on Aluminium compounds and alums

Previous questionNext question

More questions on Aluminium compounds and alums

Aluminium vessels can be used to transport concentrated nitric acid because JEE Main level
In the vapour phase aluminium chloride exists as Al2Cl6. The number of bridging chlorine atoms and the hybridisation of each Al are JEE Main level
Which of the following is NOT an alum? JEE Main level
Which statement about the forms of alumina is correct? JEE Main level
A little aqueous ammonia is added to a solution of potash alum, and then more ammonia is added in excess. What is observed? JEE Main level
A solution of AlCl3 in water turns blue litmus red mainly because JEE Main level