Ans: (b)
177. The ore of iron is
     (a) Dolomite
     (b) Magnetite
     (c) Bauxite
     (d) Anglesite
Ans: (b)
178. The flux added in the blast furnace is
     (a) Limestone
     (b) FeO
     (c) SiO2
     (d) MgO
Ans: (a)
179. Apart from lead tetra-ethyl, the other compound used as antiknock is
     (a) n-heptane
     (b) n-octane
     (c) iso-heptane
     (d) iso-octane
Ans: (d)
180. Refined petroleum is decolourised by
     (a) manganese dioxide
     (b) bauxite
     (c) animal charcoal
     (d) quicklime
Ans: (b)
181. Deficiency of iron causes
     (a) nervous disorders
     (b) heart diseases
     (c) anaemia
     (d) impairment of vision
Ans: (c)
182. An essential condition for rusting is
     (a) high temperature
     (b) light
     (c) moisture
     (d) dry air
Ans: (c)
183. Jeweller"s rouge is
     (a) magnetic oxide of iron
     (b) ferric oxide
     (c) ferrous oxide
     (d) ferrous carbonate
Ans: (b)
184. In addition to nitric acid, another acid which may render iron passive is
     (a) acetic acid
     (b) oxalic acid
     (c) chromic acid
     (d) citric acid
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