Question

1 molal aqueous solution of which of the following compounds will show the highest freezing point?

• A. $\left[Co\right(H_{2}O{)}_{3}C{l}_3].3H_{2}O$
• B. $\left[Co\right(H_{2}O{)}_6]C{l}_3$
• C. $\left[Co\right(H_{2}O{)}_{5}Cl]C{l}_2.H_{2}O$
• D. $\left[Co\right(H_{2}O{)}_{4}C{l}_2]Cl.2H_{2}O$

Answer 1

The correct option is A $\left[Co\right(H_{2}O{)}_{3}C{l}_3].3H_{2}O$

The complex giving the least number of ions during dissolution will have the lowest depression in freezing point. Thus $\left[Co\right(H_{2}O{)}_{3}C{l}_3].3H_{2}O$ will have the highest freezing point.