Question

In which of the following pairs of solutions will the values of the van't Hoff factor be the same?

• A. $0.05 MK _{4}\left[ Fe ( CN )_{6}\right]$ and $0.10 M FeSO _{4}$
• B. $0.10 M K _{4}\left[ Fe ( CN )_{6}\right]$ and $0.05 M FeSO _{4} \cdot\left( NH _{4}\right)_{2} SO _{4}$ $6 H _{2} O$
• C. $0.20 M NaCl$ and $0.10 M BaCl _{2}$
• D. $0.05 M FeSO _{4}\left( NH _{4}\right)_{2} SO _{4} \cdot 6 H _{2} O$ and $0.02 M KCl$. $MgCl _{2} .6 H _{2} O$

Answer 1

Answer: (B), (D)

Those which have same no of ions after dissociation will have same Van't Hoff factor.

$K _{4}\left[ Fe ( CN )_{6}\right] \& FeSO _{4} \cdot\left( NH _{4}\right)_{2} SO _{4} \cdot 6 H _{2} O$ have 5 ions each

$\& FeSO _{4}\left( NH _{4}\right)_{2} SO _{4} \cdot 6 H _{2} O \& KCl . MgCl _{2} \cdot 6 H _{2} O$ have ions each