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The pyknometric density of sodium chloride crystal is `2.165xx10^3 " kg m"^(-3)` while its X-ray density is `2.178xx10^3 " kg m"^(-3)` . The fraction of the unoccupied sites in sodium chloride crystal isA. 5.96B. `5.96xx10^(-2)`C. `5.96xx10^(-1)`D. `5.96xx10^(-3)` |
Answer» Correct Answer - D Molar volume from pyknometric density =`M/(2.165xx10^3)m^3` Molar volume from X-ray density `=M/(2.178xx10^3)m^3` `therefore` Volume unoccupied `=M/10^3(1/2.165-1/2.178)m^3=(0.013Mxx10^(-3))/(2.165xx2.178)` `therefore` Fraction unoccupied `=((0.013Mxx10^(-3))/(2.165xx2.178))//((Mxx10^(-3))/2.165)=5.96xx10^(-3)` |
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