JEE Main & Advanced Chemistry The Solid State / ठोस प्रावस्था Question Bank Mock Test - Solid State

  • question_answer
    The density of solid argon (Ar = 40 g/mol) is 1.68 g/mL at 40 K. If the argon atom is assumed to be a sphere of radius \[1.50\times {{10}^{-8}}\] cm, what % of solid Ar is apparently empty space? (use \[{{N}_{A}}\] = \[6\times {{10}^{23}}\])

    A) 35.64   

    B) 64.36

    C) 74                    

    D) none of these

    Correct Answer: B

    Solution :

    [b] \[1c{{m}^{3}}=1ml\] \[\Rightarrow d=1.68g/c{{m}^{3}},\]mol \[wt=40,\] \[{{N}_{A}}=6\times {{10}^{23}}\] \[\Rightarrow \frac{d\times {{N}_{A}}}{mol.wt}=\frac{Z}{{{a}^{3}}}\] Efficiency \[=\frac{Z\times \frac{4}{3}\pi {{R}^{3}}}{{{a}^{3}}}=\frac{d\times {{N}_{A}}\times \frac{4\pi }{3}\pi {{R}^{3}}}{mol.wt}\] \[=\frac{1.68\times 6\times {{10}^{23}}\times 4\times 3.14\times {{(1.50\times {{10}^{-8}})}^{3}}}{40\times 3}\]\[=0.35604\] % efficiency = 35.604% \[\Rightarrow void%=100-35.604%=64.39%\]


You need to login to perform this action.
You will be redirected in 3 sec spinner