Verified Solution • 2025–26 Session moderate

QJEEM10Che02e: JEE Main 2010 Chemistry - Class 12 JEEM10Che02e Solution: A solution containing 2.675g of CoCl 3 . 6NH 3 (molar mass =…

A solution containing 2.675g of CoCl3. 6NH3 (molar mass = 267.5 g mol–1) is passed through a cation exchanger. The chloride ions obtained in solution were treated with excess of AgNO3 to give 4.78 g of AgCl (molar mass = 143.5 g mol–1). The formula of the complex is : (At. Mass of Ag = 108 u)

Multiple Choice Options

  • A [Co(NH3)6]Cl3
  • B [CoCl2(NH3)4]Cl
  • C [CoCl3(NH3)3]
  • D [CoCl(NH3)5]Cl2

Step-by-Step Verified Solution

CoCl3.6NH32.675g⟶xCl−

xCl−+AgNO3⟶xAgCl↓4.78g

Number of moles of the complex

=2.675267.5=0.01= {{2.675} \over {267.5}} = 0.01 moles

Number of moles of AgClAgCl obtained

=4.78143.5=0.03= {{4.78} \over {143.5}} = 0.03 moles

∴\therefore    \,\,\, Number of moles of AgClAgCl obtained

=3×  = 3 \times \,\, No. of moles of complex

∴\therefore    \,\,\, n=0.030.01=3n = {{0.03} \over {0.01}} = 3

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