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Lithium metal crystal has body-centred cubic structure. Its density is 0.53 g cm^(-3) and its molecular mass is 6.94 g mol^(-1). Calculate the volume of a unit cell of lithium metal. [NA = 6.023 xx 10^(23) mol^(-1)] |
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Answer» Solution :For bcc structure `z=2`. Apply the relation : `d=(zxxM)/(a^(3)xxN_(A)) or a^(3)=(zxxM)/(d xxN_(A))` Substituting the VALUES, we GET `a^(3)=(2xx6.94)/(0.53xx6.023xx10^(23))` or `"VOLUME of unit cell "(a^(3))=(13.88)/(3.192)xx10^(-23)=4.348xx10^(-23)cm^(3)`. |
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