Question

A $0.0020\, M$ aqueous solution of an ionic compound $Co \left( NH _{3}\right)_{5}\left( NO _{2}\right) Cl$ freezes at $-0.00732^{\circ} C$. Number of moles of ions which 1 mole of ionic compound produces on being dissolved in water will be : $\left( k _{ f }=1.86^{\circ} C / m \right)-$

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

Answer: (B)

$\Delta T _{ f } = ik _{ f }. m$

$i =\frac{\Delta T _{ f }}{ k _{ f } \cdot m }$

$=\frac{0.00732}{1.86 \times 0.002}=\frac{0.00732}{0.00372}$

$i =2$

Compound will be $\left.\left[ Co \left( NH _{3}\right)_{5}\right] NO _{5} NO _{2}\right] Cl$

Total possible ions $=2$