1. Salts of which of the following elements provide colours to fireworks?
(a) Zinc and sulphur
(b)Potassium and mercury
(c) Strontium and barium
(d) Chromium and nickel
2. The metal always found in free state is—
(a) Gold
(b) Sodium
(c) Silver
(d) Copper
3. The most abundant metal in the earth’s crust is—
(a) Magnesium
(b) Aluminium
(c) Calcium
(d) Iron
4. Most abundant element on the earth’s crust by weight is—
(a) Oxygen
(b) Iron
(c) Silicon
(d) Aluminium
5. An important constituent of amalgam is—
(a) Al
(b) Ag
(c) Hg
(d) Mg
6. Which method is used for the purification of Bauxite ore?
(a) Magnetic separation
(b) Electrolysis
(c) Leaching
(d) Levigation
7. Gravity separation process may be used for concentration of—
(a) Calamine
(b) Chalcopyrite
(c) Haematite
(d) Bauxite
8. The substance used as an activator in froth floatation process is—
(a) Pine oil
(b) Potassium ethyl xanthate
(c) Copper sulphate
(d) Sodium Cyanide
9. In roasting—
(a) no metal impurities are removed
(b) ore becomes porous
(c) moisture is removed
(d) all the above
10. In roasting the ores are generally converted into—
(a) Metal oxides
(b) Metals
(c) Hydrated metal oxides
(d) None of these
Note : Answers will be updated soon...........
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