Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
0 votes

The pycnometric density of sodium chloride crystal is $2.165\times 10^3kg m^{-3}$ while its X-ray density is $2.178\times 10^3kg m^{-3}$.The fraction of the unoccupied sites in sodium chloride crystal is

$\begin{array}{1 1}5.96\times 10^{-3}\\4.96\times 10^{-3}\\3.96\times 10^{-3}\\2.96\times 10^{-3}\end{array} $

Can you answer this question?

1 Answer

0 votes
Molar volume from pycnometric density =$\large\frac{M}{2.165\times 10^3}$$m^3$
Molar volume from X-ray density =$\large\frac{M}{2.178\times 10^3}$$m^3$
$\therefore$ Volume occupied =$\large\frac{M}{10^3}\big(\frac{1}{2.165}-\frac{1}{2.178}\big)$$m^3$
$\Rightarrow \large\frac{M}{10^3}\big(\large\frac{0.013}{2.165\times 2.178}\big)$$m^3$
Fraction unoccupied =$\large\frac{\big(\Large\frac{0.013M\times 10^{-3}}{2.165\times 2.178}\big)}{\Large\frac{M\times 10^{-3}}{2.165}}$
$\Rightarrow 5.96\times 10^{-3}$
answered Aug 1, 2014 by sreemathi.v

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, AIPMT Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App