JEE Main202523 Jan 2025Morning ShiftChemistryCoordination CompoundsActual
CrCl ₃ xNH ₃ can exist as a complex. 0.1 molal aqueous solution of this complex shows a depression in freezing point of 0.558^ C . Assuming 100 % ionisation of this complex and coordination number of Cr is 6 , the complex will be (Given K _ f =1.86 ~K ~kg ~mol ⁻¹ )
Options
- A[ Cr ( NH ₃ )₅ Cl ] Cl ₂
- B[ Cr ( NH ₃ )₆ ] Cl ₃
- C[ Cr ( NH ₃ )₃ Cl ₃ ]
- D[ Cr ( NH ₃ )₄ Cl ₂ ] Cl
Correct answer
A. [ Cr ( NH ₃ )₅ Cl ] Cl ₂
Step-by-step solution
aligned & T_f=i K_f m & 0.558=i 1.86 0.1 & i= 0.558 0.186 =3 aligned Number of ions when 100 % ionisation takes place =3 [ Cr ( NH ₃ )₅ Cl ] Cl ₂ aqueous solution [ Cr ( NH ₃ )₅ Cl ²⁺ ]²⁺+2 Cl ⁻ Number of ions =3