A 0.0020 M aqueous solution of an ionic compound `Co(NH_(3))_(4)(NO_(2))_(2)Cl` freeze at - `0.00732^(@)C`. Number of moles of ions which 1 mol of ionic compound produces on being dissolved in water will be `(K_(f)=1.86^(@)C//m)`.

Options

A. 3
B. 4
C. 1
D. 2

Answer

D

Explanation

The number of moles produced by 1 mole of ionic compound
`DeltaT_(f)=iK_(f)m, i=DeltaT_(f)//K_(f)m`
`DeltaT_(f)=0-(-0.00732)`
`=0.00732^(@)C`
`K_(f)=1.86^(@)C//m`
`m=0.0020`
`i=(0.00732)/(1.86xx0.0020)`
`=1.96~~2`