AP EAMCET201823 Apr 2018Morning ShiftChemistryGeneral Principles and Processes of Isolation of MetalsActual
The ore which is concentrated by leaching
Options
- APbS
- BAl ₂ O ₃ 2 H ₂ O
- CSnO ₂
- DFe ₂ O ₃
Correct answer
B. Al ₂ O ₃ 2 H ₂ O
Step-by-step solution
Leaching is a process in which powdered ore is treated with certain reagents, which dissolves the ore leaving behind impurities in undissolved form. Aluminium ore is concentrated by this method, bauxite ( Al ₂ O ₃ 2 H ₂ O ) contain ferric oxide, titanium oxide and silica as impurities. Bauxite is treated with aqueous solution of caustic soda. Alumina get dissolved forming soluble sodium aluminate leaving behind impurities. Al ₂ O ₃+6 NaOH 2 Na ₃ AlO ₃+3 H ₂ O