If the freezing point of a 0.01 molal aqueous solution of a cobalt (III) chloride-ammonia complex (which behaves as a strong electrolyte) is -0.0558 ° C , the number of chloride(s) in the coordination sphere of the complex is [Kf for water =1.86 Kkg mol- 1 ]

Question

If the freezing point of a 0.01 molal aqueous solution of a cobalt (III) chloride-ammonia complex (which behaves as a strong electrolyte) is -0.0558 ° C , the number of chloride(s) in the coordination sphere of the complex is [Kf for water =1.86 Kkg mol- 1 ] (A) 1 (B) 2 (C) 4 (D) 3

Tardigrade Admin · Accepted Answer

Δ Tf=iKfm 0.0558=i× 1.86× 0.01 i=3 As Co is in +3 oxidation state so formula should be [ Co ( NH 3)5 Cl ] Cl 2 ⋅[ Co 3+. forms octahedral complexes ]

Q. If the freezing point of a 0.01 molal aqueous solution of a cobalt (III) chloride-ammonia complex (which behaves as a strong electrolyte) is -0.0558 $^{\circ} C$ , the number of chloride(s) in the coordination sphere of the complex is [Kf for water $= 1.86$ Kkg $m o l^{- 1}$ ]

$1$

$2$

$4$

$3$

$Δ T_{f} = i K_{f} m$

$0.0558 = i \times 1.86 \times 0.01$

$i = 3$

As Co is in +3 oxidation state so formula should be $[C o (N H_{3})_{5} Cl] C l_{2} \cdot [C o^{3 +}$ forms octahedral complexes $]$

Q. If the freezing point of a 0.01 molal aqueous solution of a cobalt (III) chloride-ammonia complex (which behaves as a strong electrolyte) is -0.0558 ∘C , the number of chloride(s) in the coordination sphere of the complex is [Kf for water =1.86 Kkg mol−1 ]

1

2

4

3

ΔTf​=iKf​m 0.0558=i×1.86×0.01 i=3 As Co is in +3 oxidation state so formula should be [Co(NH3​)5​Cl]Cl2​⋅[Co3+ forms octahedral complexes ]

Q. If the freezing point of a 0.01 molal aqueous solution of a cobalt (III) chloride-ammonia complex (which behaves as a strong electrolyte) is -0.0558 $^{\circ} C$ , the number of chloride(s) in the coordination sphere of the complex is [Kf for water $= 1.86$ Kkg $m o l^{- 1}$ ]

$1$

$2$

$4$

$3$

$Δ T_{f} = i K_{f} m$

$0.0558 = i \times 1.86 \times 0.01$

$i = 3$

As Co is in +3 oxidation state so formula should be $[C o (N H_{3})_{5} Cl] C l_{2} \cdot [C o^{3 +}$ forms octahedral complexes $]$