Question

The density of a pure substance 'X' whose atoms pack in cubic close pack arrangement is 1 g/cc. If all tetrahedral voids are occupied by 'Y' atoms. The value of '3a' is ______ g/cc, if the density of resulting solid is 'a' g/cc.

[Given: Atomic mass (X) = 30 g/mol, (Y) = 20 g/mol]

विकल्प

• 2

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Answer 1

The density of a pure substance 'X' whose atoms pack in cubic close pack arrangement is 1 g/cc. If all tetrahedral voids are occupied by 'Y' atoms. The value of '3a' is 7 g/cc, if the density of resulting solid is 'a' g/cc.

Explanation:

d_A = `(4"M"_"X")/("N"_"A""V")` = 1 g/cc

d_B = `(8"M"_"Y")/("N"_"A""V")`

`("d"_"A")/("d"_"B") = 30/(2 xx 20) = 3/4`

d_B = `4/3` g/cc

Total density = d_A + d_B

= `(1 + 4/3) "g"//"cc"`

= `7/3  "g"//"cc"`

Now, 3a = `7/3 × 3` = 7 g/cc