Which of the followed statement is incorrect ?

Options

A. Cassiterite is an oxide ore of tin.
B. Tin metal is obtained by the carbon reduction of black tin ( purified ore of tin ).
C. In the extraction of lead from galena, the roasting and self `-` reduction are carried out in the same furnace at different temperature.
D. Reducing agent of haematite in blast `-` furnace is coke in upper part and CO in lower part of furnace.

Answer

4

Explanation

`(1)` Cassiterite contains iron and maganese tungstate, called as Wol-framite. They have magnetic properties .
`(2)` Purified ore that contains `70% SnO_(2)` is called black tin.
`SnO_(2)+2CrarrSn+2CO("carbon reduction")`
`(3)` Roasting is done at moderate temperature in presence of air in reverberatory furnace. Then aire supply is stopped and temperature is increased to melt the mass when self - reduction takes place.
`(4)` At 500-800 K ( lower temperature range in the lower part of blast furnace ) `:`
`3 Fe_(2)O_(3)+CO rarr 2 Fe_(3)O_(4)+CO_(2)`
`Fe_(3)O_(4)+CO rarr 3Fe+4 CO_(2)`
`Fe_(2)O_(3)+CO rarr 2FeO+CO_(2)`
At `900-1500 K` (higher temperature range in the lower part of blast furnance):
`C+CO_(2)rarr2CO," "FeO+COrarrFe+CO_(2)`