`M=169` gm /mol
Vol. of solvent `=200 cm^(3)=2L`
`R=0*0821L atm K^(-) "mol"^(-1)`
`pi V= n RT`
No. of atoms situated at 8 corners of unit cell of fcc type
No. of atoms on each sphere
Total no. of sphere present in each faces of unit cell
Thus, total spheres present in fcc type `=1+3=4`
Various stpes involved in the extraction of pure metals from their ores are :
(a) Concentration of ores.
(b) Conversion of ores into oxides.
(c) Reduction of ores to form crude metals.
(d) Refining of metals.