In aluminium extraction by the Bayer process, alumina is extracted from bauxite by sodium hydroxide at high temperatures and pressures
Solid impurities such as Fe2O3 and SiO2 are removed and then Al(OH)4- is reprecipitated
In the industrial world
carbon dioxide is added to precipitate the alumina
temperature and pressure are dropped and the super saturated solution seeded
both (A) and (B) are practised
the water is evaporated
Which statement is incorrect?
Phenol is a weak acid
Phenol is an aromatic compound
Phenol liberates CO2 from Na2CO3 solution
Phenol is soluble in NaOH
In which of the following reactions new carbon-carbon bond is not formed ?
Cannizaro reaction
Wurtz reaction
Aldol condensation
Friedel-Craft reaction
A.
Cannizaro reaction
D.
Friedel-Craft reaction
(b)
(c)
(d)
For making distinction between 2-pentanone and 3-pentanone, the reagent to be employed is
K2Cr2O7/H2SO4
Zn-Hg/HCl
SeO2
Iodine/NaOH
The catalyst used for olefin polymerisation is
Ziegler-Natta catalyst
Wilkinson catalyst
Raney nickel catalyst
Merrifield resin
Which of the following contributes to the double helical structure of DNA ?
Hydrogen bond
Covalent bond
Disulphide bond
van der Waals' force