A diatomic molecule X2
has a body-centred cubic
(bcc) structure with a cell edge of 300 pm. The
density of the molecule is 6.17 g cm–3. The number
of molecules present in 200 g of X2
is :
(Avogadro constant (N
A) = 6 $\times$ 1023 mol–1
)
Solution
d = ${{Z \times M} \over {{a^3} \times {N_A}}}$
<br><br>$\Rightarrow$ 6.17 = $${{2 \times M} \over {{{\left( {3 \times {{10}^{ - 8}}} \right)}^3} \times 6 \times {{10}^{23}}}}$$ [For BCC Z = 2]
<br><br>$\Rightarrow$ M = 50 g/mol
<br><br>Number of moles in 200 gm = ${{{200} \over {50}}}$ = 4
<br><br>$\therefore$ Number of molecules = 4$\times$N<sub>A</sub>
About this question
Subject: Chemistry · Chapter: States of Matter · Topic: Gas Laws
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