InterviewSolution
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InterviewSolution
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A crystalline solid of a pure substance has a face-centred cubic structure with a cell edge of 400 pm. If the density of the substance in the crystal is `8 g cm^(-3)`, then the number of atoms present in 256g of the crystal is `N xx 10^(24)`. The value of `N` is |
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Answer» Correct Answer - 2 We know, `Z=(a^(3)xxd xx N_(A))/(m)` Molar mass of solid can be calculated as, `m=(a^(3)xxd xx N_(A))/(Z)` `=((400xx10^(-10))^(3)xx8xxN_(A))/(4)` `=(64xx2xx10^(-24))N_(A)` Number of atoms `=("Mass")/("Molar mass")xxN_(A)` `=(256)/((64xx2xx10^(-24)N_(A)))xxN_(A)` `=2xx10^(24)` `therefore " "N=2` |
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