Tiêu đề DPP 2 Solutions.pdf ✅

Class : XIIth Subject : CHEMISTRY Date : DPP No. : 2 1 (b) Metals which are inert towards many common reagents are called noble metals. 2 (b) Follow text. 3 (a) Fe does not form amalgam with Hg. 4 (b) Peat is an early stage in the formation of coal from vegetable matter. 5 (a) It is a fact. 6 (a) It is definition of roasting. 7 (a) Due to the formation of K2MnO4. 8 (a) Other methods are used for extraction of Al from its ores. 9 (b) It is a fact. 10 (b) The method of zone refining of metals is based on the principle of greater solubility of the impurity in the molten state than in the solid. Elements which are used as semiconductors like Si, Ge, Ga etc are refined by this method 11 (c) Bauxite is Al2O3 ∙ 2H2O . 12 (d) Pyrolusite ― MnO2 Malachite ― CuCO3.Cu(OH)2 Diaspore ―Al2O3.H2O Cassiterite ―SnO2 13 (a) Fluorspar (CaF2 ), Cryolite (na3AlF6 ) Feldspar (KAlSi3O3), Topic :- Isolation Elements Solutions