5. Where do we use handpicking and washing methods in oir daily life? Give example. How do you correlate these examples with enrichment of ore?

1. The impurity present in the ore is called as         [ ]
   a)Gangue       b)flux         c)Slag         d)Mineral


2. Which of the following is a carbonate ore?         [ ]
   a)Magnesite         b)Bauxite         c)Gypsum         d)Galena


3. Which of the following is the correct formula of Gypsum         [ ]
   a)CuSO₄. 2H₂O         b)CaSO₄. ½ H₂O        c)CuSO₄. 5H₂O         d)CaSO₄. 2H₂O


4. The oil used in the froth floatation process is         [ ]
   a) kerosene oil         b)pine oil         c)coconut oil         d) olive oil.


5. Froth floatation is method used for the purification of ______ore.         [ ]
   a)sulphide         b)oxide        c)carbonate        d)nitrate


6. Galena is an ore of         [ ]
   a)Zn         b)Pb         c)Hg         d)Al


7. The metal that occurs in the native form is         [ ]
   a)Pb         b)Au         c)Fe         d)Hg

The most abundant metal in the earth’s crust is         [ ]
a)Silver         b)Aluminium         c)zinc         d)iron

8. The reducing agent in thermite process is         [ ]
   a)Al         b)Mg         c)Fe        d)Si


9. The purpose of smelting an ore is         [ ]
   a)Oxidise         b)Reduce         c)Neutralise         d)None of these

Suggested Experiments

1. Suggest an experiment to prove that the presence of air and water are essential for corrosion. Explain the procedure. (AS₃)

Suggested Projects

1. Collect information about extraction of metaks of low reactivity silver, platinum and gold and prepare a report. (AS₄)