Q. HCl was passed through a solution of $CaCl_2$, $MgCl_2$ and NaCl. Which of the following compound(s) crystallise(s) ?
A) Only NaCl
B) Only $MgCl_2$
C) NaCl, $MgCl_2$ and $CaCl_2$
D) Both $MgCl_2$ and $CaCl_2$
Explanation
[Solution] By the common ion effect, the least soluble NaCl crystallises; $MgCl_2$ and $CaCl_2$ are more soluble and remain in solution. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.