When CO2 is passed through solution of sodium aluminate, precipitate of which compound is formed?
Al(OH)3
Al2O3
Na2CO3
No ppt
A.
Al(OH)3
In Hall's process, for purifying the bauxite ore, the solution containing sodium meta aluminate is warmed to 50-60C and carbon dioxide is circulated through it, Al2(OH)3 separates out as precipitate.
2NaAl02 + CO2 + 3H202Al(OH)3 + Na2CO3
Which of the following is not the correct match?
Leaching : Ag
Zone refining : Sn
Liquation : Pb
van Arkel : Zr
The purpose of smelting an ore is to :
oxidise it
reduce it
obtain an alloy
separate volatile impurities
What is the role of aniline or cresol when added in a froth floatation process?
Stabilizer
Depressant
Wetting agent
All of these