Easy INTEGER +4 / -1 PYQ · JEE Mains 2021

The unit cell of copper corresponds to a face centered cube of edge length 3.596 $\mathop A\limits^o$ with one copper atom at each lattice point. The calculated density of copper in kg/m3 is ___________. [Molar mass of Cu : 63.54 g; Avogadro Number = 6.022 $\times$ 1023]

Answer (integer) 9077

Solution

<p>Density of copper, $d = {{Z \times M} \over {{a^3} \times {N_A}}}$</p> <p>Given, Z = 4, for fcc lattice,</p> <p>M = 63.54 g mol<sup>$-$1</sup></p> <p>= 63.54 $\times$ 10<sup>$-$3</sup> kg mol<sup>$-$1</sup>,</p> <p>a = 3.596 $\mathop A\limits^o$ = 3.596 $\times$ 10<sup>$-$10</sup> m,</p> <p>N<sub>A</sub> = 6.022 $\times$ 10<sup>23</sup> mol<sup>$-$1</sup></p> <p>On putting given values, we get</p> <p>$$ \Rightarrow d = {{4 \times (63.54 \times {{10}^{ - 3}})} \over {{{(3.596 \times {{10}^{ - 10}})}^3} \times (6.022 \times {{10}^{23}})}}$$ kg/m<sup>3</sup></p> <p>$= 9076.26 \simeq 9077$ kg/m<sup>3</sup></p>

About this question

Subject: Chemistry · Chapter: States of Matter · Topic: Gas Laws

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