1. Tardigrade
  2. Question
  3. Chemistry
  4. Density of NaCl is 1.8 g/cc . KCl has similar unit cell as NaCl and the following relationship among ionic radii exist r(Na+)=0.5r(Cl-),r(K+)=0.8r(Cl-) . The density of KCl is

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. Density of $NaCl$ is $1.8\,g/cc$ . $KCl$ has similar unit cell as $NaCl$ and the following relationship among ionic radii exist $r\left(Na^{+}\right)=0.5r\left(Cl^{-}\right),r\left(K^{+}\right)=0.8r\left(Cl^{-}\right)$ . The density of $KCl$ is

NTA AbhyasNTA Abhyas 2022

Solution:

Density $=\frac{4 \times M}{N_{A} \times a^{3}}$
$\frac{d_{NaCl}}{d_{KCl}}=\frac{58 . 5}{74 . 5}\left(\frac{a_{KC l}}{a_{NaCl}}\right)^{3}$
$d_{KCl}=1.8\times \frac{74 . 5}{58 . 5}\left(\frac{1 . 5 r \left(Cl^{-}\right)}{1 . 8 r \left(Cl^{-}\right)}\right)^{3}=1.33\,g/cc$